CN114466995A - Air conditioner - Google Patents

Air conditioner Download PDF

Info

Publication number
CN114466995A
CN114466995A CN202080065478.6A CN202080065478A CN114466995A CN 114466995 A CN114466995 A CN 114466995A CN 202080065478 A CN202080065478 A CN 202080065478A CN 114466995 A CN114466995 A CN 114466995A
Authority
CN
China
Prior art keywords
heating
cooling
heat exchanger
unit
intermediate heat
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202080065478.6A
Other languages
Chinese (zh)
Other versions
CN114466995B (en
Inventor
滨岛哲磨
木口行雄
浅利峻
有田照平
三浦贤
清水智纪
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Carrier Corp
Original Assignee
Toshiba Carrier Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toshiba Carrier Corp filed Critical Toshiba Carrier Corp
Publication of CN114466995A publication Critical patent/CN114466995A/en
Application granted granted Critical
Publication of CN114466995B publication Critical patent/CN114466995B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
    • F24F11/63—Electronic processing
    • F24F11/65—Electronic processing for selecting an operating mode
    • F24F11/67—Switching between heating and cooling modes
    • 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
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F1/00—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station
    • F24F1/0003—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station characterised by a split arrangement, wherein parts of the air-conditioning system, e.g. evaporator and condenser, are in separately located units
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F24F11/46—Improving electric energy efficiency or saving
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
    • F24F11/63—Electronic processing
    • F24F11/64—Electronic processing using pre-stored data
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
    • F24F11/63—Electronic processing
    • F24F11/65—Electronic processing for selecting an operating mode
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/86—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling compressors within refrigeration or heat pump circuits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/89—Arrangement or mounting of control or safety devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/30—Arrangement or mounting of heat-exchangers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F5/00—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater
    • 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
    • F25B25/00—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00
    • F25B25/005—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00 using primary and secondary 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
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/30—Expansion means; Dispositions thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/30—Expansion means; Dispositions thereof
    • F25B41/31—Expansion valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/40—Fluid line arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/005—Arrangement or mounting of control or safety devices of safety devices
    • 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
    • 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
    • F25B49/022—Compressor control arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • F24F2110/10—Temperature
    • F24F2110/12—Temperature of the outside air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2140/00—Control inputs relating to system states
    • F24F2140/20—Heat-exchange fluid temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2140/00—Control inputs relating to system states
    • F24F2140/50—Load
    • 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
    • F25B2313/007—Compression machines, plants or systems with reversible cycle not otherwise provided for three pipes connecting the outdoor side to the indoor side with 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
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0231—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units with simultaneous cooling and heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/025—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units
    • F25B2313/0253—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units in parallel arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/031—Sensor arrangements
    • F25B2313/0312—Pressure 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
    • F25B2313/0314—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
    • F25B2339/00—Details of evaporators; Details of condensers
    • F25B2339/04—Details of condensers
    • F25B2339/047—Water-cooled condensers
    • 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
    • F25B2500/19—Calculation of parameters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/02—Compressor control
    • F25B2600/025—Compressor control by controlling speed
    • F25B2600/0253—Compressor control by controlling speed with variable speed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2513—Expansion valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/19—Pressures
    • F25B2700/197—Pressures of the evaporator
    • 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
    • F25B2700/2106—Temperatures of fresh outdoor air
    • 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
    • F25B2700/2117—Temperatures of an evaporator
    • F25B2700/21174—Temperatures of an evaporator of the refrigerant at the inlet of the evaporator

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Chemical & Material Sciences (AREA)
  • Signal Processing (AREA)
  • Fuzzy Systems (AREA)
  • Mathematical Physics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

An air conditioner according to an embodiment of the present invention performs a heating operation and a cooling operation, and causes a part of exhaust gas to flow into one of a plurality of intermediate heat exchangers and condense, causes the remaining part of the exhaust gas to condense in an outdoor side heat exchanger, causes the condensed condensate to be mixed with a refrigerant condensed in the intermediate heat exchanger through a liquid pipe, causes the mixed condensate to flow into another intermediate heat exchanger through a second expansion valve and evaporate, the cooling-heating hybrid operation in which cooling is prioritized is performed by flowing the exhaust gas into one of the plurality of intermediate heat exchangers and condensing the exhaust gas, flowing a part of the exhaust gas into the outdoor heat exchanger through the liquid pipe and evaporating the exhaust gas, and flowing the remaining part of the condensate into the other intermediate heat exchanger through the second expansion valve and evaporating the condensate.

Description

Air conditioner
Technical Field
Embodiments of the present invention relate to an air conditioner that performs cooling and heating by circulating a heating agent such as water.
Background
In recent years, the use of a part of HFC (hydrofluorocarbon) refrigerants having a high Global Warming Potential (GWP) has been regarded as a problem, and the use thereof has been limited in stages, including the modification of fluorine gas regulations in europe. Therefore, development of air conditioners using refrigerants having low GWP is being advanced, and R410A, which is the mainstream among household air conditioners and commercial air conditioners, has been replaced with R32.
On the other hand, R32 is a slightly flammable (A2L) refrigerant, and when used in a variable refrigerant flow rate (VRF) type air conditioner having a large refrigerant charge amount, for example, safety in the case of leakage into a room needs to be taken into consideration. Therefore, while the VRF type air conditioner continues to use R410A, a system has been proposed in which water is circulated as a heating agent to perform cooling and heating of the indoor units individually, according to research and development in recent years. As one example, in an air conditioner of this type, a relay unit is provided between an outdoor unit and an indoor unit, the outdoor unit and the relay unit are connected by a refrigerant pipe, and the relay unit and the indoor unit are connected by a water pipe. In the relay unit, the refrigerant and the heating agent exchange heat. Therefore, a refrigerant pipe passes from the outdoor unit to the relay unit, and a water pipe passes between the relay unit and the indoor unit. This ensures safety against leakage of the refrigerant in the room, and a slightly flammable refrigerant such as R32 can be used.
Documents of the prior art
Patent document
Patent document 1: japanese patent No. 5236009
Disclosure of Invention
Technical problem to be solved by the invention
In the relay unit of the air conditioner, the flow path is appropriately switched by the flow path switching valve so that cold water is circulated to the indoor unit that requests the cooling operation and hot water is circulated to the indoor unit that requests the heating operation. When the air conditioner is operated in a mode in which cooling and heating are mixed (cooling-heating mixed operation), the outdoor unit is operated in the following manner according to the proportion of the setting request of the operation mode of the indoor unit. For example, when the ratio of the cooling requests to the indoor units is more than half, the outdoor unit performs a cooling-heating hybrid operation in which cooling is prioritized. On the other hand, when the ratio of the heating requests to the indoor units is more than a half, the outdoor unit performs the cooling/heating hybrid operation in which heating is prioritized. Thus, when the operation mode of the outdoor unit is switched, the capability of the operation mode predicted to be requested more, such as cooling in summer and heating in winter, may be reduced in accordance with the change in the ratio of the setting request of the indoor unit. In addition, a hunting of the circulation state may occur along with the switching of the operation mode of the outdoor unit.
The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a water circulation type air conditioner capable of suppressing a decrease in the capacity of an operation mode predicted to be frequently requested and the occurrence of hunting in a circulation state.
In the above-described air conditioner, the rotation speed of the compressor provided in the outdoor unit is controlled based on the heating-medium temperature on the downstream side of the heating medium in the intermediate heat exchanger. At this time, the target heating medium temperature of the intermediate heat exchanger is also determined so that the cooling capacity or the heating capacity of the indoor unit reaches a predetermined capacity. Therefore, for example, when the target cooling capacity on the indoor unit side is the minimum capacity of the air conditioner, the rotation speed of the outdoor unit compressor is excessive with respect to the cooling capacity required on the indoor unit side, and thus energy exceeding the required amount is used.
The present invention has been made in view of the above circumstances, and a second object thereof is to provide a water circulation type air conditioner capable of saving energy.
Further, in the above-described air conditioner, for example, when the cooling-heating mixed operation is performed in an environment lower than 0 ℃ in winter, the evaporation temperature of the evaporator at the time of the refrigeration cycle may be lowered to the same temperature as that of the outdoor exchanger. This is because, when a cooling-heating hybrid operation in which heating is prioritized is performed in winter, the pressure of the refrigerant flowing through the intermediate cooling heat exchanger is led to the outdoor heat exchanger side because the outdoor heat exchanger is an evaporator, and the evaporation temperature decreases. In this case, when the refrigerant is water, the intermediate heat exchanger for cooling may freeze, and therefore, it is necessary to prevent the freezing.
Further, in the above-described air conditioner, water circulates in each indoor unit. Therefore, it is necessary to consider piping resistance due to the length of the flow path of water so that the flow rate of water does not vary among the indoor units. As a countermeasure, for example, a flow rate control valve for each indoor unit is disposed in the relay unit, but in this case, the housing size, cost, and the like of the relay unit are likely to increase. In particular, when the exhaust heat of the outdoor unit is used for heat recovery, a water heat exchanger, a flow path switching valve, a circulation pump, and a flow rate control valve having a capacity corresponding to the VRF need to be housed in the relay unit. As a result, the size of the housing of the relay unit may be further increased, and there may be problems such as an increase in the number of persons for mounting the relay unit and an increase in the installation space.
In the air conditioner, the cooling-only operation or the heating-only operation can be performed using two heat exchangers, but, for example, when the relay unit is installed in a narrow space such as a ceiling back surface, the size of the height method of the relay unit is limited, and it is necessary to configure the cooling-only heat exchanger or the heating-only heat exchanger using a plurality of small heat exchangers. In this case, the cost of the intermediate heat exchanger as a single unit also increases, and the manufacturing cost also increases due to an increase in the number of parts and an increase in the number of welded portions.
The present invention has been made in view of the above circumstances, and a third object of the present invention is to provide a water circulation type air conditioner capable of preventing freezing of a cooling intermediate heat exchanger.
Further, a fourth object of the present invention is to provide a circulation type air conditioner capable of suppressing the manufacturing cost.
Means for solving the problems
According to an embodiment, an air conditioner includes: an outdoor unit, a heat exchange unit, an indoor unit, a valve unit, and a control unit. The outdoor unit has a compressor for circulating a refrigerant, an outdoor-side heat exchanger, and a first expansion valve. The heat exchange unit has a plurality of intermediate heat exchangers for exchanging heat between a refrigerant and a heating agent, and a second expansion valve corresponding to the plurality of intermediate heat exchangers. The indoor unit has an indoor-side heat exchanger for exchanging heat between the heating agent and indoor air. The valve unit has a flow path switching valve for allowing either one of the refrigerant cooled by the intermediate heat exchanger and the refrigerant heated by the intermediate heat exchanger to flow into the indoor-side heat exchanger. The control unit has a control unit for controlling each unit, and the outdoor unit, the heat exchange unit, the indoor unit, and the valve unit are respectively divided into housings. The outdoor unit and the heat exchange unit are connected by a liquid pipe that conveys the condensate condensed by the outdoor heat exchanger to the heat exchange unit or conveys the condensate condensed by the intermediate heat exchanger to the outdoor unit, a suction gas pipe that conveys the refrigerant evaporated by the intermediate heat exchanger to the outdoor unit, and a discharge gas pipe that conveys the discharge gas compressed by the compressor to the heat exchange unit.
The control unit performs any one of heating operation, cooling-heating-mixing operation with priority on cooling, and cooling-heating-mixing operation with priority on heating. In the heating operation, the control unit causes exhaust gas to flow into the intermediate heat exchanger. In the cooling operation, the control unit condenses the discharge gas in the outdoor heat exchanger, and causes the condensed condensate to flow into the intermediate heat exchanger via the second expansion valve. In the cooling-heating mixing operation in which the cooling is prioritized, the control unit may cause a part of the exhaust gas to flow into one of the plurality of intermediate heat exchangers and condense the exhaust gas, cause the remaining part of the exhaust gas to flow through the outdoor-side heat exchanger and condense the exhaust gas, cause the condensed condensate to be mixed with the refrigerant condensed by the intermediate heat exchanger via the liquid pipe, and cause the mixed condensate to flow into the other intermediate heat exchanger via the second expansion valve and evaporate. In the cooling-heating hybrid operation in which the heating is prioritized, the control unit may cause the exhaust gas to flow into one of the plurality of intermediate heat exchangers and condense, cause a part of the exhaust gas to flow into the outdoor-side heat exchanger through the liquid pipe and evaporate, and cause the remaining part of the condensate to flow into the other intermediate heat exchanger through the second expansion valve and evaporate.
Drawings
Fig. 1 is a diagram schematically showing the structure of an air conditioner according to embodiment 1.
Fig. 2 is a diagram schematically showing a piping system of an air conditioner according to embodiment 1.
Fig. 3 is a diagram schematically showing an example of installation of each unit of the air conditioner according to embodiment 1.
Fig. 4A is a diagram schematically illustrating a piping system of the heat-source-side refrigeration cycle in the cooling-heating hybrid operation of the air conditioner according to embodiment 1.
Fig. 4B is a morel diagram of the heat source side refrigeration cycle in the cooling-heating hybrid operation of the air conditioner according to embodiment 1.
FIG. 5 shows the density (kg/m) of the refrigerant in embodiment 13) Ratio (%), refrigerant flow rate (m/s), (refrigerant flow rate)2And the ratio (%) and the compression ratio, and the discharge gas pipe, the liquid pipe, and the suction gas pipe.
Fig. 6A is a diagram schematically showing a piping system of an air conditioner according to a first modification.
Fig. 6B is a diagram schematically showing a piping system of an air conditioner according to a second modification.
Fig. 7 is a control flow showing an operation mode selection process of the outdoor unit in the air conditioner according to embodiment 1.
Fig. 8 is a control flowchart showing a summer operation mode selection process of the outdoor unit in the air conditioner according to embodiment 1.
Fig. 9 is a control flowchart showing winter operation mode selection processing of the outdoor unit in the air conditioner according to embodiment 1.
Fig. 10 is a control flowchart showing a middle-period operation mode selection process of the outdoor unit in the air conditioner according to embodiment 1.
Fig. 11 is a diagram showing an example of a change over time in the ratio of a cooling request to a heating request for an indoor unit in the air conditioner according to embodiment 1.
Fig. 12A is a diagram showing an example of a change in the operation mode of the outdoor unit in an intermediate period in accordance with the outside air temperature when the ratio of the cooling request to the heating request changes as shown in fig. 11 in the air conditioner according to embodiment 1.
Fig. 12B is a diagram showing an example of a change in the operation mode of the outdoor unit in summer according to the outside air temperature when the ratio of the cooling request to the heating request changes as shown in fig. 11 in the air conditioner according to embodiment 1.
Fig. 12C is a diagram showing an example of a change in the operation mode of the outdoor unit in winter according to the outside air temperature when the ratio of the cooling request to the heating request changes as shown in fig. 11 in the air conditioner according to embodiment 1.
Fig. 13 is a diagram showing the relationship between the operation mode and the target temperature of the heating agent in the cooling operation and the heating operation of embodiment 2.
Fig. 14 is a control flowchart showing an example of the switching processing of the operation mode in embodiment 2.
Fig. 15 is a diagram schematically showing the structure of an air conditioner according to embodiment 3.
Fig. 16 is a diagram showing an example of installation of the intermediate cooling heat exchanger according to embodiment 3.
Fig. 17 is a diagram showing an example of installation of the intermediate heat exchanger for heating according to embodiment 3.
Detailed Description
Embodiments of the present invention will be described below with reference to the drawings.
(embodiment mode 1)
Fig. 1 is a diagram schematically showing the structure of an air conditioner according to the present embodiment. Fig. 2 is a diagram schematically showing a piping system of an air conditioner according to the present embodiment. Fig. 3 schematically shows an example of installation of each unit of the air conditioner according to the present embodiment.
As shown in fig. 1, 2, and 3, the air conditioner 1 includes an outdoor unit 2, a heat exchange unit 3, a valve unit 4, and an indoor unit 5. The units are divided into units and formed with housings, and the units are connected by predetermined pipes 6 to 9. Of these units, for example, the outdoor unit 2 is provided on the roof RF of the building B, and the heat exchange unit 3, the valve unit 4, and the indoor unit 5 are provided in the ceiling space CS of each of the floors 1F, 2F of the building B, and the like. The ceiling space CS is a predetermined space such as a space between a beam on the back of the ceiling of the building B and the ceiling. In addition, fig. 1, 2, and 3 schematically show the air conditioner 1, and the number of units and the number of pipes can be increased or decreased as appropriate from the illustrated embodiment.
Each of these units 2, 3, 4, and 5 includes a control unit 20, 30, 40, and 50 that controls the operation of each component described later. These control units 20, 30, 40, and 50 constitute control means of the air conditioner 1, each including a CPU, a memory, a storage device (nonvolatile memory), an input/output circuit, a timer, and the like, and execute predetermined arithmetic processing. For example, each of the control units 20, 30, 40, and 50 reads various data via the input/output circuit, performs arithmetic processing by the CPU using a program read from the storage device to the memory, and controls the operation of each unit component based on the processing result. At this time, the control sections 20, 30, 40, 50 transmit and receive control signals with each unit constituent member and with each other by wire or wirelessly.
In the present embodiment, the control panel 100 is connected to the outdoor unit 2. The control panel 100 includes a plurality of switches, buttons, dials, and the like, and the operation of the air conditioner can be set and adjusted by an administrator (user) operating the switches, buttons, dials, and the like. In the present embodiment, the operation mode of the air conditioner 1 can be changed by the administrator operating the control panel 100.
The control unit 30 of the heat exchange unit 3 stores the setting of the target temperature of the heating agent in each operation mode of the cooling operation and the heating operation, and acquires the temperature of the heating agent by a temperature sensor 3d described later. The control unit 20 of the outdoor unit 2 controls the rotation speed of the compressor 2a based on the temperature of the heating medium acquired by the temperature sensor 3d and the set target temperature. The setting of the target temperature will be described with reference to fig. 4, and the control (the switching process of the operation mode) will be described with reference to fig. 5. As the cooling operation and the heating operation of the air conditioner 1, there are two operation modes: a first mode (also referred to as a normal operation mode); and a second mode (hereinafter also referred to as an energy saving operation mode) that operates with power saving than the first mode.
The outdoor unit 2 and the heat exchange unit 3 constitute a heat source side refrigeration cycle in which a refrigerant circulates in the air conditioner 1. Further, the heat exchange unit 3, the valve unit 4, and the indoor unit 5 constitute a heating medium flow path cycle in the air conditioner 1.
The outdoor unit 2 and the heat exchange unit 3 are connected by a pipe (hereinafter referred to as a refrigerant pipe) 6. The refrigerant pipe 6 includes a liquid pipe 6a, a suction gas pipe 6b, and a discharge gas pipe 6 c.
The outdoor unit 2 includes, as main portions, a compressor 2a, a check valve 2b, an oil separator 2c, a four-way valve 2d, an outdoor-side heat exchanger 2e, an expansion valve 2f, a liquid tank 2g, an outdoor-unit fan 2h, a memory 2i, opening and closing valves 2j, 2k, and an outside air temperature sensor 2 l. The outdoor unit fan 2h and the outside air temperature sensor 2l are connected by pipes inside the casing 21 and are disposed in refrigerant flow paths that circulate between the heat exchange unit 3 and the respective units. The outdoor unit fan 2h is provided adjacent to the outdoor side heat exchanger 2e on a wall portion of the casing 21. The housing 21 defines the outline of the outdoor unit 2.
The heat exchange unit 3 is configured to house, as main portions, expansion valves 3a, 31a, 32a, and 33a, intermediate heat exchangers 3b, 31b, and 32b, an opening/closing valve 3c, and temperature sensors 3d, 31d, and 32d in a casing 31. The shell 31 defines the outline of the heat exchange unit 3. The expansion valves 31a and 32a correspond to a second expansion valve that faces an expansion valve 2f (first expansion valve) provided in the outdoor unit 2, and the expansion valve 33a corresponds to a third expansion valve that faces the expansion valve 2 f. The intermediate heat exchanger 3b exchanges heat between the refrigerant and the heating medium. In the present embodiment, the heat exchange unit 3 includes a plurality of intermediate heat exchangers 3b, at least one of which 3b cools the heating agent by the refrigerant, and the other intermediate heat exchangers 3b heat the heating agent by the refrigerant. The refrigerant is, for example, R32 having a lower Global Warming Potential (GWP) than R410A and R407C. As an example, the heating agent is water, but may be an antifreeze. The temperature sensor 3d is provided on the downstream side of the intermediate heat exchanger 3b, and detects the temperature of the heating medium flowing out of the intermediate heat exchanger 3 b. The temperature thus detected is sent to the control section 20.
Since the heat exchange unit 3 includes the cooling intermediate heat exchanger 31b and the heating intermediate heat exchanger 32b, the air conditioner 1 can perform either one of the cooling operation and the heating operation or both of them simultaneously.
The operation modes of the heat source side refrigeration cycle constituted by the outdoor unit 2 and the heat exchange unit 3 in the cooling operation, the heating operation, and the cooling/heating hybrid operation of the air conditioner 1 will be described. In the above operation described below, the control units 40 and 50 and the control units 20 and 30 of the valve unit 4 and the indoor unit 5 in the outdoor unit 2 and the heat exchange unit 3 appropriately transmit and receive control signals, and the components of the units 2 and 3 are operated.
During the cooling operation, the outdoor unit 2 and the heat exchange unit 3 operate as follows. At this time, in the outdoor unit 2, the compressor 2a sucks the gas refrigerant from the suction port 21a, compresses the sucked gas refrigerant, and discharges the compressed gas refrigerant from the discharge port 22 a. The compressor 2a is a device that compresses a refrigerant to a high-temperature and high-pressure state, and is, for example, an inverter compressor or the like whose capacity can be controlled. The discharged gas refrigerant (discharge gas) passes through the check valve 2b, and the lubricating oil component is separated by the oil separator 2c and flows into the outdoor-side heat exchanger 2 e. At this time, a part of the gas refrigerant is branched by the four-way valve 2d and flows into the outdoor heat exchanger 2 e. The inflowing gas refrigerant radiates heat to the outside air through the outdoor side heat exchanger 2e, and is condensed and liquefied. The outdoor heat exchanger 2e exchanges heat between the refrigerant and the outside air, and functions as a condenser during the cooling operation. The liquefied refrigerant (condensate) is decompressed by the expansion valve 2f, stored in the liquid tank 2g, and supplied to the heat exchange unit 3 through the liquid pipe 6 a. The outdoor unit fan 2h draws outside air into the casing 21 and flows into the outdoor-side heat exchanger 2e, and then is discharged outside the casing 21.
In the heat exchange unit 3, the supplied liquid refrigerant (condensate) is expanded by the cooling expansion valve 31a and flows into the cooling intermediate heat exchanger 31 b. The inflowing liquid refrigerant absorbs heat from the heating agent through the cooling intermediate heat exchanger 31b and evaporates and vaporizes. The vaporized refrigerant (evaporation gas) is returned to the outdoor unit 2 through the expansion valve 33a for pressure control and the suction gas pipe 6 b. The evaporated gas is defined as a refrigerant that passes through the intermediate heat exchanger for cooling 31b and undergoes an evaporation process. The evaporated gas may contain a refrigerant that is not completely evaporated, has a dryness of 1.0 or less, and contains a liquid refrigerant. The expansion valve 33a for pressure control controls the evaporation temperature of the intermediate heat exchanger 31b for cooling, and prevents freezing of water as a heating medium.
The evaporated gas returned to the outdoor unit 2 is separated into a gas refrigerant and a liquid refrigerant in the accumulator 2 i. The separated gas refrigerant is sucked into the compressor 2a from the suction port 21a and compressed again. On the other hand, the separated liquid refrigerant is stored in the accumulator 2 i.
In contrast, during the heating operation, the outdoor unit 2 and the heat exchange unit 3 operate as follows. At this time, in the outdoor unit 2, the gas refrigerant discharged from the compressor 2a passes through the check valve 2b in the same manner as in the cooling operation, and the lubricating oil component is separated in the oil separator 2 c. At this time, the opening/closing valve 2j is opened, and the gas refrigerant (discharge gas) is supplied to the heat exchange unit 3 through the discharge gas pipe 6 c.
In the heat exchange unit 3, the opening/closing valve 3c is opened, and the supplied gas refrigerant radiates heat to the heating agent through the intermediate heat exchanger for heating 32b, and is condensed and liquefied. The liquefied refrigerant (condensate) is expanded by the heating expansion valve 32a and returned to the outdoor unit 2 through the liquid pipe 6 a.
At this time, the opening/closing valve 2k is opened, and the liquid refrigerant (condensate) returned to the outdoor unit 2 is expanded by the expansion valve 2f via the liquid tank 2g and flows into the outdoor heat exchanger 2 e. The liquid refrigerant after inflow absorbs heat from the outside air by the outdoor side heat exchanger 2e and is evaporated and vaporized. During the heating operation, the outdoor heat exchanger 2e functions as an evaporator. At this time, the outdoor unit fan 2h draws outside air into the casing 21 and causes the outside air to flow into the outdoor side heat exchanger 2e and then to be discharged out of the casing 21. The vaporized refrigerant (vapor gas) is sucked into the compressor 2a from the suction port 21a through the four-way valve 2d and the accumulator 2i and is compressed again.
When the mixed operation of cooling and heating is performed, the outdoor unit 2 and the heat exchange unit 3 operate as follows, respectively. At this time, in the outdoor unit 2, the gas refrigerant (exhaust gas) discharged from the compressor 2a is supplied to the heat exchange unit 3 through the exhaust gas pipe 6c in the same manner as in the heating operation. In the heat exchange unit 3, the supplied gas refrigerant radiates heat to the heating agent by the intermediate heat exchanger 32b for heating, and is condensed and liquefied, as in the heating operation. The liquefied refrigerant (condensate) is expanded by the heating expansion valve 32a and the cooling expansion valve 31a, and flows into the cooling intermediate heat exchanger 31 b. The inflowing liquid refrigerant (condensate) absorbs heat from the heating agent via the intermediate heat exchanger for cooling 31b and evaporates and vaporizes.
At this time, when cooling is prioritized over heating, the flow path is switched to supply the liquid refrigerant (condensate) from the outdoor unit 2 to the heat exchange unit 3. On the other hand, when heating is prioritized over cooling, the flow path is switched to supply the liquid refrigerant (condensate) from the heat exchange unit 3 to the outdoor unit 2. For example, when the opening/ closing valves 2j, 2k, and 3c are opened and closed, the flow path is changed by the four-way valve 2d, and the supply direction of the liquid refrigerant passing through the liquid pipe 6a is switched. When the opening and closing valves 2j, 2k, 3c are closed, the liquid refrigerant is supplied from the outdoor unit 2 to the heat exchange unit 3 through the four-way valve 2 d. When the opening and closing valves 2j, 2k, 3c are opened, the liquid refrigerant is supplied from the heat exchange unit 3 to the outdoor unit 2 through the four-way valve 2 d.
The heat exchange unit 3, the valve unit 4, and the indoor unit 5 constitute a heating medium flow path cycle in the air conditioner 1.
The valve unit 4 is interposed between the heat exchange unit 3 and the indoor unit 5. The valve unit 4 is connected to the heat exchange unit 3 through the heating agent pipes 7 and 8, respectively.
The heating medium pipe 7 constitutes a flow path for the heating medium (hereinafter referred to as cooling heating medium) cooled by the cooling intermediate heat exchanger 31 b. The heating agent pipe 7 includes a cooling heating agent supply pipe 7a and a cooling heating agent return pipe 7 b. The cooling heating medium supply pipe 7a is a flow path for supplying the cooling heating medium from the heat exchange unit 3 to the valve unit 4. The cooling heating-medium return pipe 7b is a flow path for returning the cooling heating medium from the valve unit 4 to the heat exchange unit 3.
The heating medium pipe 8 constitutes a flow path for the heating medium (hereinafter referred to as heating medium) heated by the intermediate heat exchanger for heating 32 b. The heating agent pipe 8 includes a heating agent supply pipe 8a for heating and a heating agent return pipe 8b for heating. The heating refrigerant supply pipe 8a is a flow path for supplying the heating refrigerant from the heat exchange unit 3 to the valve unit 4. The heating refrigerant return pipe 8b is a flow path for returning the heating refrigerant from the valve unit 4 to the heat exchange unit 3.
Further, the valve unit 4 is connected to the indoor unit 5 through a distribution pipe 9. The distribution pipe 9 includes a water inlet pipe 9a supplying the heating agent to the indoor unit 5 and a water return pipe 9b returning the heating agent to the valve unit 4. The inlet pipe 9a constitutes a flow path for supplying the cooling heating medium supplied from the cooling heating medium supply pipe 7a and the heating medium supplied from the heating medium supply pipe 8a to the indoor unit 5. The return pipe 9b constitutes a flow path for returning the cooling heating medium and the heating medium to the valve unit 4.
Therefore, the cooling heating agent and the heating agent are circulated between the heat exchange unit 3 and the indoor unit 5 via the valve unit 4, respectively. In the configuration example shown in fig. 2, the cooling heating agent supply pipe 7a and the heating agent supply pipe 8a are branched into four inlet pipes 9a, respectively, and the cooling heating agent and the heating agent are distributed to four indoor units 5, respectively. The distributed cooling heating medium and heating medium are returned from the four water return pipes 9b to the valve unit 4, respectively, and circulated to the heat exchange unit 3 through the cooling heating medium return pipe 7b or the heating medium return pipe 8 b.
Therefore, the pipe diameters of the heating agent pipes 7 and 8 and the distribution pipe 9 are different. In the present embodiment, as an example, the pipe diameters of the cooling refrigerant supply pipe 7a and the cooling refrigerant return pipe 7b are larger than the pipe diameter of the inlet pipe 9 a. The pipe diameters of the heating refrigerant supply pipe 8a and the heating refrigerant return pipe 8b are larger than the pipe diameter of the return pipe 9 b. Therefore, the heating agent can be smoothly and stably circulated between the heating agent pipes 7 and 8 and the distribution pipe 9.
The pipe diameters of the heating agent pipes 7 and 8 may be different depending on the total connection capacity of the indoor unit 5. Since each capacity (capacity) of the indoor unit 5 has a different design flow rate, the rated flow rate is determined for each capacity. Assuming that 0.5HP to 5HP indoor units are classified into a series, the rated flow rates thereof are different from each other, and it is considered that about 3 series of circulation pumps 5a are required. In the present embodiment, the heating agent flow path is assumed to be a closed circuit, but the pipe flow velocity is set to an appropriate value in consideration of air intrusion due to contamination with foreign matter, water leakage, or the like. Therefore, the pipe diameters of the heating agent pipes 7 and 8 are different depending on the total connection capacity of the indoor unit 5.
The valve unit 4 is configured to include the flow path switching valve 4a as a main portion in the housing 41. The flow path switching valve 4a is a valve that allows either the cooling heating medium or the heating medium to flow into the indoor-side heat exchanger 5b of the indoor unit 5, and includes a water inlet valve 41a and a water return valve 42 a. The water inlet valve 41a and the water return valve 42a are three-way valves that are opened and closed by the control portion 40, the details of which will be described later. The housing 41 defines the outline of the valve unit 4.
The indoor unit 5 includes, as main portions, a circulation pump 5a, an indoor-side heat exchanger 5b, an indoor-unit fan 5c, and an information acquisition section 5 d. The circulation pump 5a and the indoor-side heat exchanger 5b are connected by piping in the casing 51, and are disposed in the heating agent flow path that circulates between the valve unit 4 and the heat exchange unit 3. The indoor unit fan 5c and the information acquisition unit 5d are disposed adjacent to a wall portion of the casing 51. The housing 51 defines the outline of the indoor unit 5. The circulation pump 5a circulates the heating agent in the heating agent flow path.
The information acquisition unit 5d is an interface unit for exchanging information between the indoor unit 5 and the user, and is, for example, a panel for operation, a switch, a button, a display for display, or the like. The information acquiring unit 5d acquires information (data) such as operation start of the indoor unit 5, mode selection of the cooling operation and the heating operation, and setting of the indoor temperature, and supplies the acquired information to the control unit 50.
The heating agent flow path circulation constituted by the heat exchange unit 3, the valve unit 4, and the indoor unit 5 will be described below.
In the heating agent flow path cycle, the cooled heating agent (cooling heating agent) is supplied from the cooling heating agent supply pipe 7a to the valve unit 4 while releasing heat to the refrigerant by the cooling intermediate heat exchanger 31b of the heat exchange unit 3. The heating agent (heating agent) that absorbs heat from the refrigerant and is heated by the intermediate heating heat exchanger 32b is supplied from the heating agent supply pipe 8 a. The supplied cooling heating agent and heating agent are supplied from the inlet pipe 9a to the indoor unit 5 through the inlet valve 41 a. The water inlet valve 41a supplies either one of the cooling heating agent or the heating agent to the indoor unit 5. Specifically, the flow path of the valve unit 4 is switched so that the inlet valve 41a is connected to the cooling refrigerant supply pipe 7a, thereby supplying the cooling refrigerant to the indoor unit 5 performing the cooling operation. On the other hand, the flow path of the valve unit 4 is switched so that the feed valve 41a is connected to the heating agent supply pipe 8a for heating, thereby supplying the heating agent to the indoor unit 5 performing the heating operation. The control unit 50 switches between the cooling operation and the heating operation in the indoor unit 5 in accordance with, for example, the selection of the operation mode by the user acquired by the information acquisition unit 5 d.
Further, the heating agent returned from the indoor unit 5 is returned from the return pipe 9b to the valve unit 4 through the return valve 42 a. The return valve 42a operates in correspondence with the inlet valve 41a on the same flow path, and returns the heating medium supplied to the indoor unit 5 to the valve unit 4. Specifically, the return valve 42a switches the flow path of the valve unit 4 so that the heating medium returned from the indoor unit 5 performing the cooling operation is guided to the cooling heating medium return pipe 7 b. The heating medium guided to the cooling heating medium return pipe 7b is cooled again by radiating heat to the refrigerant by the cooling intermediate heat exchanger 31 b. On the other hand, the return valve 42a switches the flow path of the valve unit 4 so as to guide the heating agent returned from the indoor unit 5 performing the heating operation to the heating agent return pipe 8b for heating. The heating medium guided to the heating medium return pipe 8b passes through the intermediate heating heat exchanger 32b, receives heat from the refrigerant, and is heated again.
In the indoor unit 5, the circulation pump 5a operates in accordance with the operation or stop of the indoor unit 5, and sucks and discharges the cooling heating medium or the heating medium to the indoor-side heat exchanger 5 b. The circulation pump 5a is an inverter type pump capable of increasing or decreasing the rotation speed, and the rotation speed is increased or decreased based on, for example, the outlet temperature of the heating agent (the outlet water temperature of the indoor-side heat exchanger 5 b). The indoor-side heat exchanger 5b exchanges heat between the indoor air and the heating medium to adjust the temperature. The indoor unit fan 5c sucks indoor air into the casing 51, flows the air into the indoor-side heat exchanger 5b, and blows the temperature-adjusted air from the casing 51 to the air-conditioned space. The indoor unit fan 5c rotates almost at the same time as an operation start request for cooling or heating and stops almost at the same time as an operation stop request. The order of stopping the circulation pump 5a and the indoor unit fan 5c may be such that either one is stopped first. As one example, from the viewpoint of sensing the indoor temperature, it is desirable to first stop the circulation pump 5a and continue to rotate the indoor unit fan 5c when thermally disconnected.
In the present embodiment, the air conditioner 1, specifically, the outdoor unit 2 is operated in any one of the cooling operation, the heating operation, the cooling-heating hybrid operation in which cooling is prioritized, and the cooling-heating hybrid operation in which heating is prioritized. These operation modes may be selected by the control section 20 based on the outside air temperature detected by the outside air temperature sensor 2l, or may be selected based on an instruction from the control panel 100 of the outdoor unit 2, for example.
The cooling operation is an operation mode in which the discharge gas of the compressor 2a is condensed in the outdoor side heat exchanger 2e, and the condensate flows into the cooling intermediate heat exchanger 31b via the cooling expansion valve 31 a.
The heating operation is an operation mode in which the discharge gas of the compressor 2a flows into the intermediate heat exchanger for heating 32 b.
The cooling-preferential cooling-heating hybrid operation is an operation mode in which the cooling operation and the heating operation are performed mixedly, but the cooling operation is preferentially performed appropriately. In the cooling-heating hybrid operation in which cooling is prioritized, a part of the exhaust gas of the compressor 2a flows into the intermediate heat exchanger 32b for heating and is condensed, and the remaining part of the exhaust gas is condensed by the outdoor heat exchanger 2 e. The two condensates are mixed, and the mixed condensate flows into the intermediate cooling heat exchanger 31b through the expansion valve 31a for cooling and is evaporated.
The heating-prioritized cooling-heating mixed operation is an operation mode in which the cooling operation and the heating operation are performed mixedly, but the heating operation is preferentially performed appropriately. In the cooling-heating hybrid operation in which heating is prioritized, the discharge gas of the compressor 2a flows into the intermediate heat exchanger for heating 32b and is condensed. A part of the condensate flows into the outdoor heat exchanger 2e through the liquid pipe 6a and is evaporated. The remaining part of the condensate flows into the intermediate heat exchanger for cooling 31b through the expansion valve for heating 32a and the expansion valve for cooling 31a and is evaporated.
Fig. 4A and 4B show the heat source side refrigeration cycle in these cooling and heating combined operations. Fig. 4A is a diagram schematically showing a piping system of the heat-source-side refrigeration cycle, and fig. 4B is a morel diagram of the heat-source-side refrigeration cycle. In fig. 4B, changes in the state of the refrigerant at the compressor 2a are indicated from P1 to P2, changes in the state of the refrigerant at the outdoor side heat exchanger 2e (condenser) are indicated from P2 to P3, changes in the state of the refrigerant at the cooling expansion valve 31a are indicated from P3a to P4, changes in the state of the refrigerant at the cooling intermediate heat exchanger 31B are indicated from P4 to P5, and changes in the state of the refrigerant at the pressure control expansion valve 33a are indicated from P5 to P1. In fig. 4B, changes in the state of the refrigerant in the heating expansion valves 32a and 2f are indicated from P3B to P6, and changes in the state of the refrigerant in the outdoor heat exchanger 2e (evaporator) are indicated from P6 to P7 (P1). P1 to P7 shown by the white dots in fig. 4B correspond to respective points of the piping system shown in fig. 4A. L41 shown in fig. 4B is a saturated liquid line and L42 is a saturated vapor line.
The pipe diameter of the pipe 6 of the air conditioner 1 will be described.
First, the pressure loss dP of the refrigerant can be generally obtained by the following expressions (1) and (2).
[ mathematical formula 1]
dP＝p×g×dH…(1)
[ mathematical formula 2]
Figure BDA0003552217920000141
Where dP is pressure loss, dH is total head loss, g is gravitational acceleration, ρ is fluid density, λ is tube friction coefficient, l is tube length, d is tube inside diameter, and ν is average flow velocity in the tube. In addition to this, the present invention is,
[ mathematical formula 3]
Figure BDA0003552217920000151
Are coefficients for various losses other than friction.
As can be seen from the above equations (1) and (2), when the pipe diameter d is fixed, the pipe friction coefficient λ, the fluid density ρ, and the average flow velocity ν in the pipe have large influences on the pressure loss dP.
Here, in the present embodiment, an example of the refrigerant density and the refrigerant flow rate of the discharge gas pipe 6c, the liquid pipe 6a, and the suction gas pipe 6b when the pipe diameter d is fixed is shown in table T1 of fig. 5. Further, the pressure loss ratio is the refrigerant density (refrigerant flow rate)2The ratio of (a) to (b).
The refrigerant density (kg/m) is shown in FIG. 53) Ratio (%), refrigerant flow rate (m/s), (refrigerant flow rate)2The ratio (%) and the compression ratio, and the discharge gas piping, the liquid piping, and the suction gas piping. As shown in fig. 5, the refrigerant density is the discharge gas pipe "94.2", the liquid pipe "980.4", and the suction gas pipe "34.6", and the ratio is the discharge gas pipe "100", the liquid pipe "1041", and the suction gas pipe "37". The refrigerant flow rates were discharge gas pipe "23.3", liquid pipe "2.2" and suction gas pipe "63.4", the pressure loss was discharge gas pipe "542.4", liquid pipe "5.0" and suction gas pipe "4025.7", and the ratios were discharge gas pipe "100", "liquid pipe" 10 ", and", suction gas piping" 272 ".
In the pressure loss ratio, the value of the liquid pipe is the smallest and the value of the suction gas pipe 6b is the largest. That is, in order to equalize the pressure loss coefficients, the pipe diameters d of the suction gas pipe 6b, the discharge gas pipe 6c, and the liquid pipe 6a need to be set such that the suction gas pipe 6b > the discharge gas pipe 6c > the liquid pipe 6 a. Thus, the air conditioner 1 can be an efficient and excellent system by configuring the pipe diameter d of the air conditioner 1.
In fig. 4A, when the heating load is large, the outdoor heat exchanger 2e needs to function as an evaporator. Therefore, for example, when the outside air temperature in winter is 0 ℃, the outdoor heat exchanger 2e absorbs heat from the outside air, and therefore the evaporation temperature of the outdoor heat exchanger 2e is about-10 ℃.
Here, if the air conditioner 1 does not have the expansion valve (expansion valve for intermediate pressure control) 33a in fig. 4A, the evaporation temperature of the intermediate heat exchanger 31b for cooling becomes substantially the same temperature as the outdoor heat exchanger 2 e. Therefore, when water is used as the heating medium, the cooling intermediate heat exchanger 31b may freeze and crack (actually, the evaporation temperature of the cooling intermediate heat exchanger may slightly increase corresponding to the pipe pressure loss).
Therefore, in the air conditioner 1a of the first modification shown in fig. 6A, the temperature sensor 34 is provided in addition to the expansion valve 33 a. The temperature sensor 34 detects the temperature of the refrigerant flowing into the intermediate heat exchanger 31 b. The control unit 30 controls the opening and closing of the expansion valve 33a based on the temperature detected by the temperature sensor 34. Thereby, the evaporation temperature of the intermediate heat exchanger 31b for cooling is controlled based on the detected temperature of the temperature sensor 34.
In general, it is desirable to use a plate heat exchanger formed by stacking plates as the intermediate heat exchanger, but the plate heat exchanger used as the evaporator may be provided with a flow dividing mechanism at the refrigerant inlet, and a pressure loss may occur. In contrast, in the air conditioner 1a according to the first modification, the evaporation temperature of the cooling intermediate heat exchanger 31b can be controlled based on the temperature detected by the temperature sensor 34, and therefore the risk of the cooling intermediate heat exchanger 31b breaking due to freezing can be suppressed.
In addition, in the first modification (fig. 6A), the case where the opening and closing of the expansion valve 33a is controlled based on the temperature detected by the temperature sensor 34 provided at the inlet of the intermediate heat exchanger for cooling 31b is described, but the opening and closing control of the expansion valve 33a is not limited thereto. For example, as in the air conditioner 1B of the second modification shown in fig. 6B, a pressure sensor 35 may be provided at the outlet of the intermediate heat exchanger 31B for cooling in place of the temperature sensor 34, and the control unit 30 may control the opening and closing of the expansion valve 33a based on the pressure detected by the pressure sensor 35. More specifically, the control portion 30 may convert the pressure value detected by the pressure sensor 35 into a saturation temperature, and may control the opening and closing of the expansion valve 33a based on the converted saturation temperature. Even with this configuration, the risk of the intermediate heat exchanger for cooling 31b breaking due to freezing can be suppressed, as in the case where the temperature sensor 34 is provided.
The basic configuration of the air conditioner 1a shown in fig. 6A and the air conditioner 1B shown in fig. 6B is the same as that of the air conditioner 1 of embodiment 1 described above. Therefore, the same configurations as those of the air conditioner 1 are denoted by the same reference numerals in the drawings, and the description thereof is omitted.
Next, one example of selection control (operation mode selection processing) of these operation modes based on the outside air temperature will be described according to the control flow of the control portion 20. Fig. 7 shows a control flow of the control section 20 in the operation mode selection process (S0) of the outdoor unit 2.
As shown in fig. 7, in the operation mode selection process (S0), the operation of the air conditioner 1 is started by the control units 20, 30, 40, and 50 of the respective units 2, 3, 4, and 5 being interlocked with each other (S01). For example, the control unit 20 starts the operation of the outdoor unit 2, the control unit 30 starts the operation of the heat exchange unit 3, the control unit 40 starts the operation of the valve unit 4, and the control unit 50 starts the operation of the indoor unit 5. The operation of the air conditioner 1 is a precondition for the operation mode selection process (S0). With this state as a trigger, the control unit 20 may execute the operation mode selection process (S0). Therefore, when the air conditioner 1 is not operating, the operation mode selection process is not executed (S0).
In a state where the air conditioner 1 is operating, the control unit 20 causes the outside air temperature sensor 2l TO detect the outside air Temperature (TO) (S02). The outside air Temperature (TO) is a temperature outside the air-conditioning target space, and as one example, is an atmospheric temperature of the outdoor unit 2. The outside air temperature sensor 2l transmits detection data (a detected value of TO) TO the control unit 20.
When the detection data is transmitted, the control section 20 determines the summer condition and the winter condition. The summer condition is a determination condition as TO whether or not the outside air Temperature (TO) is equal TO or higher than a predetermined Temperature (TH). The winter condition is a determination condition as TO whether or not the outside air Temperature (TO) is equal TO or lower than a predetermined Temperature (TL). TH and TL are temperatures (threshold temperatures) that define a range of outside air Temperatures (TO), TH is a first defined temperature, and TL is a second defined temperature that is lower than TH. As an example, TH is about 28 ℃ and TL is about 18 ℃, but may be arbitrarily set, and is not limited thereto. The values of the first predetermined Temperature (TH) and the second predetermined Temperature (TL) are stored in, for example, a storage device of the control unit 20, and are read out as parameters to the memory when determining the summer condition or the winter condition.
In this example, first, the control unit 20 determines the summer condition (TO ≧ TH) (S03). When determining the summer condition, the control unit 20 compares the value of the outside air Temperature (TO) with the value of the first predetermined Temperature (TH).
In the case where the summer condition is satisfied, the control part 20 performs a summer operation mode selection process of the outdoor unit 2 (S1) (S04). The summer operation mode selection process (S1) is a process of selecting (switching) the operation mode of the outdoor unit 2 in summer according to the ratio of the cooling request and the heating request to the indoor unit 5. The details of which will be set forth later.
On the other hand, if the summer condition is not satisfied in S03, the controller 20 determines the winter condition (TO ≦ TL) (S05). When determining the winter condition, the control unit 20 compares the value of the outside air Temperature (TO) with the value of the second predetermined Temperature (TL).
In the case where the winter condition is satisfied, the control part 20 performs a winter operation mode selection process of the outdoor unit 2 (S2) (S06). The winter operation mode selection process (S2) is a process of selecting (switching) the operation mode of the outdoor unit 2 in winter according to the ratio of the cooling request and the heating request to the indoor unit 5. The details of which will be set forth later.
On the other hand, if the winter condition is not satisfied in S05, the control unit 20 executes the intermediate operation mode selection process (S3) (S07). The intermediate period operation mode selection process (S3) is a process of selecting (switching) the operation mode of the outdoor unit 2 in accordance with the ratio of the cooling request TO the heating request TO the indoor unit 5, in the summer and in the winter (TL < TO < TH). The details of which will be set forth later.
As described above, the control part 20 performs any one of the summer operation mode selection process (S1), the winter operation mode selection process (S2), and the middle period operation mode selection process (S3) according to the outside air temperature. Then, by ending these selection processes (S1, S2, S3), the operation mode selection process (S0) ends. Next, the respective selection processes (S1, S2, S3) will be explained.
Fig. 8 shows a control flow of the control unit 20 in the summer operation mode selection process (S1). As shown in fig. 8, the control unit 20 calculates the ratio of the cooling request to the heating request to the indoor unit 5 (hereinafter referred to as the cooling/heating request ratio) (S101). In the calculation, the control unit 20 acquires information (data) of a request (cooling request or heating request) for an operation mode of each indoor unit 5 from the control unit 50 of the indoor unit 5. For example, the cooling request and the heating request are set in accordance with the operation mode selected by the user from the operation panel of the information acquiring unit 5d, and the signals are transmitted to the control unit 50.
When calculating the cooling/heating request rate, the control unit 20 compares the cooling/heating request rate with a predetermined threshold value, selects an operation mode of the outdoor unit 2 as described below based on the result, and appropriately switches the operation mode. In addition to 0 (%) and 100 (%), the present embodiment uses two threshold values (a1, a2) as the prescribed threshold values. A1 is a first threshold value of the ratio of the cooling request and the heating request for the indoor unit 5. For example, the first threshold is a majority, and as an example, is about 51%. A2 is a second threshold value for the proportion of heating requests for the indoor unit 5. In other words, 100-a2 is also the second threshold for the proportion of the cooling request to the indoor unit 5. A2 is any value greater than a1 and less than 100%, for example in the range from 90% to 70%, as an example around 75%.
The control unit 20 determines whether the ratio of the heating request is zero, that is, whether the ratio of the cooling request is 100% (S102).
When the ratio of the heating requests is zero, the control unit 20 causes the outdoor unit 2 to perform the cooling operation (S103).
On the other hand, when the ratio of the heating requests is not zero, the control unit 20 determines whether the ratio of the heating requests is smaller than the first threshold (S104).
When the ratio of the heating request is smaller than the first threshold value, the control unit 20 causes the outdoor unit 2 to perform the cooling-heating hybrid operation with priority for cooling (S105).
On the other hand, when the ratio of the heating requests is equal to or greater than the first threshold, the control unit 20 determines whether the ratio of the heating requests is smaller than the second threshold (S106).
When the ratio of the heating requests is smaller than the second threshold, the control section 20 retains the heating requests to the indoor units 5 during this period (S107).
Then, the outdoor unit 2 is caused to perform a cooling-heating hybrid operation in which cooling is prioritized (S105). Therefore, when the outdoor unit 2 performs the cooling-heating mixed operation in which cooling is prioritized, the mixed operation is continued. That is, in this case, the operation mode of the outdoor unit 2 is maintained as the cooling-heating mixed operation with priority for cooling without switching.
On the other hand, when the ratio of the heating request is equal to or greater than the second threshold value, the control unit 20 determines whether the ratio of the heating request is less than 100% (S108).
When the percentage of the heating request is less than 100%, the control unit 20 causes the outdoor unit 2 to perform the cooling-heating hybrid operation with heating priority (S109). Therefore, when the outdoor unit 2 performs the cooling-heating hybrid operation with the cooling priority, the control unit 20 releases the reservation of the heating request (S107), and switches from the cooling-heating hybrid operation with the cooling priority to the cooling-heating hybrid operation with the heating priority.
On the other hand, when the ratio of the heating request is 100%, the control unit 20 causes the outdoor unit 2 to perform the heating operation (S110).
While the air conditioner 1 is operating, the control unit 20 repeats the summer operation mode selection process for the outdoor unit 2 described above (S111). Thus, the outdoor unit 2 selects the operation mode according to the ratio of the cooling/heating request, and appropriately switches the operation mode.
When the operation of the air conditioner 1 is stopped, the control unit 20 ends the summer operation mode selection process.
Fig. 9 shows a control flow of the control unit 20 in the winter season operation mode selection process (S2). As shown in fig. 9, the control unit 20 calculates the ratio of the cooling/heating request (S201). The calculation of the cooling/heating request ratio is the same as step S101 in the summer operation mode selection process (S1).
When calculating the cooling/heating request rate, the control unit 20 compares the cooling/heating request rate with a predetermined threshold value, selects the operation mode of the outdoor unit 2 as described below based on the result of comparison, and appropriately switches the operation mode. In addition to 0 (%) and 100 (%), the present embodiment uses two threshold values (a1, A3) as the prescribed threshold values. A1 is a first threshold value of the ratio of the cooling request to the heating request for the indoor unit 5, and is common to the summer operation mode selection process (S1) (about 51% as an example). A3 is a third threshold value for the proportion of heating requests for indoor unit 5. In other words, 100-a3 is also the third threshold for the proportion of the cooling request to the indoor unit 5. A3 is any value smaller than a1 and larger than 0%, for example in the range from 10% to 30%, as an example around 25%.
The control unit 20 determines whether the ratio of the cooling request is zero, that is, whether the ratio of the heating request is 100% (S202).
When the ratio of the cooling request is zero, the control unit 20 causes the outdoor unit 2 to perform the heating operation (S203).
On the other hand, when the rate of the heating request is not zero, the control unit 20 determines whether the rate of the cooling request is smaller than the first threshold (S204).
When the ratio of the cooling requests is smaller than the first threshold value, the control unit 20 causes the outdoor unit 2 to perform the cooling-heating hybrid operation with heating priority (S205).
On the other hand, when the ratio of the cooling request is equal to or greater than the first threshold value, the control unit 20 determines whether the ratio of the cooling request is smaller than the third threshold value (S206).
When the ratio of the cooling requests is smaller than the third threshold value, the control section 20 retains the cooling request to the indoor unit 5 during this period (S207).
Then, the outdoor unit 2 is caused to perform a cooling-heating hybrid operation in which heating is prioritized (S205). Therefore, when the outdoor unit 2 performs the cooling-heating mixed operation in which heating is prioritized, the mixed operation is continued. That is, in this case, the operation mode of the outdoor unit 2 is maintained as the cooling-heating mixed operation with heating priority without switching.
On the other hand, when the rate of the cooling request is equal to or higher than the third threshold value, the control unit 20 determines whether the rate of the cooling request is less than 100% (S208).
When the ratio of the cooling request is less than 100%, the control unit 20 causes the outdoor unit 2 to perform the cooling-heating hybrid operation with priority for cooling (S209). Therefore, when the outdoor unit 2 performs the cooling-heating hybrid operation with heating priority, the control unit 20 releases the reservation of the cooling request (S207), and switches from the cooling-heating hybrid operation with heating priority to the cooling-heating hybrid operation with cooling priority.
On the other hand, when the rate of the cooling request is 100%, the control unit 20 causes the outdoor unit 2 to perform the cooling operation (S210).
While the air conditioner 1 is operating, the control unit 20 repeats the winter operation mode selection process for the outdoor unit 2 described above (S211). Thus, the outdoor unit 2 selects the operation mode according to the ratio of the cooling/heating request, and appropriately switches the operation mode.
When the operation of the air conditioner 1 is stopped, the control unit 20 ends the season-shifting operation mode selection process.
Fig. 10 shows a control flow of the control unit 20 in the intermediate-period operation mode selection process (S3). As shown in fig. 10, the control unit 20 calculates the ratio of the cooling/heating request (S301). The calculation of the cooling/heating request ratio is the same as the step S101 and the winter operation mode selection process (S2) in the summer operation mode selection process (S1).
When calculating the cooling/heating request rate, the control unit 20 compares the cooling/heating request rate with a predetermined threshold value, and selects the operation mode of the outdoor unit 2 as described below based on the result of comparison, and appropriately switches the operation mode. In addition to 0 (%) and 100 (%), the present embodiment uses the first threshold value (a1) as the prescribed threshold value. A1 is a first threshold value of the ratio of the cooling request to the heating request for the indoor unit 5, and is common to the summer operation mode selection process (S1) and the winter operation mode selection process (S2) (about 51% as an example).
The control unit 20 determines whether the ratio of the heating request is zero, that is, whether the ratio of the cooling request is 100% (S302).
When the ratio of the heating requests is zero, the control unit 20 causes the outdoor unit 2 to perform the cooling operation (S303).
On the other hand, when the rate of the heating request is not zero, the control unit 20 determines whether the rate of the heating request is smaller than the first threshold (S304).
When the ratio of the heating request is smaller than the first threshold value, the control unit 20 causes the outdoor unit 2 to perform the cooling-heating hybrid operation with priority for cooling (S305).
On the other hand, when the ratio of the heating request is equal to or greater than the first threshold value, the control unit 20 determines whether the ratio of the heating request is less than 100% (S306).
When the percentage of the heating request is less than 100%, the control unit 20 causes the outdoor unit 2 to perform the cooling-heating hybrid operation with heating priority (S307). Therefore, when the outdoor unit 2 performs the cooling-heating mixed operation in which the cooling is prioritized, the control unit 20 switches from the cooling-heating mixed operation in which the cooling is prioritized to the heating-heating mixed operation in which the heating is prioritized. That is, in the middle-period operation mode selection process (S3), the heating request to the indoor unit 5 is not retained as in the summer operation mode selection process (S1), but the cooling-heating mixed operation with the cooling priority is switched to the cooling-heating mixed operation with the heating priority.
On the other hand, when the ratio of the heating request is 100%, the control unit 20 causes the outdoor unit 2 to perform the heating operation (S308).
While the air conditioner 1 is operating, the control unit 20 repeats the intermediate-period operation mode selection process for the outdoor unit 2 described above (S309). Thus, the outdoor unit 2 selects the operation mode according to the ratio of the cooling/heating request, and appropriately switches the operation mode.
When the operation of the air conditioner 1 is stopped, the control unit 20 ends the intermediate operation mode selection process.
In contrast, in the intermediate-period operation mode selection process (S3), if the rate of the cooling requests is zero, the control section 20 switches the outdoor unit 2 to the heating operation; if the ratio of the cooling requests is equal to or greater than zero and less than the first threshold value, the control section 20 switches the outdoor unit 2 to the cooling-heating mixed operation in which heating is prioritized; if the ratio of the cooling requests is not less than the first threshold value and less than 100%, the control unit 20 switches the outdoor unit 2 to the cooling-heating hybrid operation in which cooling is prioritized; if the rate of the cooling request is 100%, the control section 20 switches the outdoor unit 2 to the cooling operation. As described above, when the ratio of the cooling request is equal to or higher than the first threshold value and less than 100%, the control unit 20 switches the outdoor unit 2 from the cooling-heating mixed operation in which heating is prioritized to the cooling-heating mixed operation in which cooling is prioritized. That is, in the intermediate period operation mode selection process (S3), the cooling request to the indoor unit 5 is not retained as in the winter operation mode selection process (S2), but the outdoor unit 2 is switched from the cooling-heating mixed operation in which heating is prioritized to the cooling-heating mixed operation in which cooling is prioritized.
Fig. 11 is a diagram showing an example of a change in the ratio of the cooling request and the heating request to the indoor unit 5 with time. In this example, the aggregate of the ratios of the cooling request and the heating request to the four indoor units 5 is shown. The cooling request and the heating request are set, for example, in accordance with an operation mode of the indoor unit selected by the user from the operation panel of the information acquisition unit 5 d.
Fig. 12 shows a variation of the operation mode of the outdoor unit 2 for each season according to the outside air temperature, when the ratio of the cooling request to the heating request for the indoor unit 5 is changed, as shown in fig. 11. FIG. 10(a) is a graph showing an example of the operation mode change in the middle period (TL < TO < TH), FIG. 10(b) is a graph showing an example of the operation mode change in summer (TO ≧ TH), and FIG. 10(c) is a graph showing an example of the operation mode change in winter (TO ≦ TL).
As shown in fig. 11, for example, at time t0, the operation start control is performed in a state where the cooling requests are issued to all the indoor units 5, and then this state is maintained to time t 1. At time t1, a heating request is issued in a part of the indoor units 5, and control is performed to switch the operation mode from cooling to heating. Then, until time t5, the operation is performed in a state where the operation mode is the mixing of the cooling indoor unit 5 and the heating indoor unit 5. During this period, as the times t2, t3, and t4 pass, the rate of the heating request to the indoor unit 5 (the rate of heating in the operation mode) gradually increases. After time t5, a heating request is issued to all indoor units 5 (heating is performed in all operation modes). L11 shown in fig. 11 is a trajectory showing a change in the ratio of the heating request to the indoor unit 5, and is a boundary line of the ratio of the cooling request to the heating request. The time series is not limited to the order (ascending order) of times t0, t1, t2, t3, t4, t5, and t 6. On the contrary, the time sequence may be descending order from time t6 to time t0, or may be a time sequence of randomly arranged times other than these.
In fig. 11, a1, a2, and A3 are thresholds of the cooling and heating request ratios for the indoor units, and correspond to the first threshold, the second threshold, and the third threshold, respectively.
Fig. 12A shows the control manner of the operation mode of the outdoor unit 2 in the intermediate period (TL < TO < TH). In the intermediate period, for example, from time t0 to time t1, the operation modes of all the indoor units 5 are in the cooling state, that is, the proportion of the cooling requests to the indoor units 5 is 100%. Thus, the outdoor unit 2 is caused to perform the cooling operation.
At time t1, a heating request is issued to some of the indoor units 5, the rate of the heating request to the indoor units 5 increases from 0%, and the rate of the cooling request decreases from 100%. At this time, the outdoor unit 2 is switched from the cooling operation to the cooling-heating mixed operation in which cooling is prioritized.
At time t2, the proportion of the heating request to the indoor units 5 is A3%, and the proportion of the cooling request is 100-A3%, but the proportion of the cooling request still exceeds 100-a 1%. Therefore, the outdoor unit 2 continues the cooling-heating mixed operation in which cooling is prioritized.
At time t3, the ratio of the heating requests to the indoor units 5 is a 1%, and the ratio of the cooling requests is 100-a 1%, which are almost equal (as an example, the ratio of the heating requests is a majority). At this time, the outdoor unit 2 switches from the cooling-heating hybrid operation with priority on cooling to the cooling-heating hybrid operation with priority on heating.
At time t4, the heating request rate to the indoor unit 5 increases to a 2%, and the cooling request rate decreases to 100-a 2%, but the heating request rate does not reach 100%. Therefore, the outdoor unit 2 continues the cooling-heating mixed operation in which heating is prioritized.
At time t5, the operation mode of all the indoor units 5 is in the heating state, that is, the proportion of the heating request to the indoor units 5 becomes 100%. Therefore, the outdoor unit 2 is switched from the cooling-heating mixed operation in which heating is prioritized to the heating operation. Then, after time t5, even by time t6, the outdoor unit 2 continues the heating operation.
When the control method of the operation mode of the outdoor unit 2 at the intermediate period shown in fig. 12A is understood as a time series descending from the time t6 to the time t0, the outdoor unit 2 switches the operation mode as follows, contrary to the above control method. That is, at time t5, the heating operation is switched to the cooling/heating hybrid operation in which heating is prioritized. Next, at time t3, the cooling/heating hybrid operation with heating priority is switched to the cooling/heating hybrid operation with cooling priority. Then, at time t1, the cooling/heating hybrid operation that gives priority to cooling is switched to the cooling operation.
As described above, by switching the operation mode of the outdoor unit 2 based on the requested ratio of the operation mode of the indoor unit 5, the outdoor unit 2 can be operated in an appropriate operation mode. However, for example, in summer when it is predicted that the cooling request to the indoor unit 5 is large, or in winter when it is predicted that the heating request to the indoor unit 5 is large, a fluctuation in the cycle state or the like may occur due to a decrease in the capacity of the outdoor unit 2 or a switching of the operation mode.
Therefore, in the present embodiment, the operation mode of the outdoor unit 2 is switched as follows based on the outside air temperature in addition to the requested ratio of the operation mode of the indoor unit 5.
For example, in summer, the outdoor unit 2 is operated in the control manner of the operation mode as shown in fig. 12B.
As an example, in summer, the outside air Temperature (TO) is equal TO or higher than the first predetermined Temperature (TH) (TO ≧ TH).
As shown in fig. 12B, for example, from time t0 to time t3, the outdoor unit 2 is operated in the same control manner as the operation mode in the intermediate period shown in fig. 12A. That is, the cooling operation is performed by the outdoor unit 2 from time t0 to time t1 at which the rate of the cooling request is 100%. During the period from time t1 to time t3 at which the proportion of the cooling request drops from 100%, the outdoor unit 2 performs the cooling-priority heating-cooling mixed operation.
At time t3, even if the cooling request rate further drops to 100-a 1%, which is almost equivalent to the rate of the heating request (a 1%) (as an example, the rate of the heating request is more than half), the outdoor unit 2 continues the cooling-heating mixed operation with priority for cooling. At this time, unlike the intermediate period (fig. 12A), the switching from the cooling-heating hybrid operation with cooling priority to the cooling-heating hybrid operation with heating priority is not performed.
At time t4, when the proportion of the cooling request decreases to 100-a 2% and the proportion of the heating request increases to a 2%, the outdoor unit 2 switches from the cooling-heating hybrid operation with cooling priority to the cooling-heating hybrid operation with heating priority. That is, after the cooling operation is switched from time t1 to time t4, the cooling-heating mixed operation that gives priority to cooling is continued in the outdoor unit 2. During this period, the heating request is retained, and the cooling-heating hybrid operation with cooling priority is maintained.
In this embodiment, a threshold value a2, which is a percentage of the heating request for maintaining the cooling-heating hybrid operation with the heating request kept and the cooling priority, is set as the second threshold value, and a threshold value 100-a2, which is a percentage of the cooling request, is set as the second threshold value.
Thereafter, at time t5, when the ratio of the cooling request is 0% and the ratio of the heating request is 100%, the outdoor unit 2 switches from the cooling-heating hybrid operation with heating priority to the heating operation. Then, after time t5, even by time t6, the outdoor unit 2 continues the heating operation. During this time, the operation mode of the outdoor unit 2 is controlled in the same manner as the intermediate period shown in fig. 12A.
For example, in winter, the outdoor unit 2 is operated in the control manner of the operation mode as shown in fig. 12C. As an example, winter is when the outside air Temperature (TO) is below a second prescribed Temperature (TL) (TO ≦ TL). In fig. 12C, from time t6 to time t0 are time series in descending order.
As shown in fig. 12C, for example, from time t6 to time t3, the outdoor unit 2 is operated in the same control manner as the operation mode in the intermediate period shown in fig. 12A. That is, the outdoor unit 2 is caused to perform the heating operation from the time t6 when the ratio of the heating request is 100% to the time t 5. During the period from time t5 when the proportion of the heating request drops from 100% to time t3, the outdoor unit 2 performs the cooling-heating hybrid operation in which the heating is prioritized.
At time t3, even if the heating request rate further decreases to 100-a 1%, which is almost equal to the rate of the cooling request (a 1%) (as an example, the rate of the cooling request is more than half), the outdoor unit 2 continues the cooling-heating hybrid operation in which the heating priority is given. At this time, the switching from the cooling-heating mixed operation with heating priority to the cooling-heating mixed operation with cooling priority is not performed.
At time t2, when the proportion of the heating request decreases to A3% and the proportion of the cooling request increases to 100-A3%, the outdoor unit 2 switches from the cooling-heating mixed operation with heating priority to the cooling-heating mixed operation with cooling priority. That is, during the period from the time t5 when the heating operation is switched to the time t2, the cooling-heating mixed operation in which the heating is prioritized continues in the outdoor unit 2. During this time, the cooling request is retained, and the cooling-heating hybrid operation with heating priority is maintained.
In the present embodiment, as described above, the threshold value of the ratio of the cooling request to the cooling/heating hybrid operation in which the cooling request is retained and the heating priority is maintained is set to 100-A3 as the third threshold value, and the threshold value of the ratio of the heating request is set to A3 as the third threshold value.
Thereafter, at time t1, when the proportion of the request for heating is 0% and the proportion of the request for cooling is 100%, the outdoor unit 2 switches from the cooling-heating hybrid operation with priority for cooling to the cooling operation. Then, after time t1, even by time t0, the outdoor unit 2 continues the heating operation. The operation mode of the outdoor unit 2 during this period is controlled in the same manner as the intermediate period shown in fig. 12A.
Thus, by switching the operation mode of the outdoor unit 2 based on the outside air temperature in addition to the requested ratio of the operation mode of the indoor unit 5, the timing of switching from the cooling-heating hybrid operation with priority on cooling to the cooling-heating hybrid operation with priority on heating can be shifted (delayed). Thus, for example, in summer (TO ≧ TH), even if there is a heating request, the heating request can be retained without switching the operation mode of the outdoor unit 2, and the cooling-heating hybrid operation that is predicted TO give priority TO the cooling that is requested more can be maintained. On the other hand, in winter (TO ≦ TL), even if there is a cooling request, the cooling request can be retained without switching the operation mode of the outdoor unit 2, and the cooling-heating hybrid operation predicted TO give priority TO the request of more heating can be maintained.
Therefore, frequent switching of the operation mode of the outdoor unit 2 can be suppressed. As a result, it is possible to suppress the decrease in the capability of predicting that the operation mode is requested more and the occurrence of hunting of the cycle state. Further, even in an operation mode of the indoor unit 5 predicted to have a small request, for example, a heating mode in summer and a cooling mode in winter, when a certain request ratio (the second threshold value or the third threshold value) is exceeded, the operation mode of the outdoor unit 2 is switched. Therefore, the request reservation for the operation mode predicted to be requested less can be released, and the operation mode of the outdoor unit 2 can be switched according to the actual operation mode of the indoor unit 5 requested by the user. Therefore, the operation mode of the outdoor unit 2 can be appropriately switched to the cooling-heating hybrid operation with priority for heating even in summer, and the operation mode of the outdoor unit 2 can be appropriately switched to the cooling-heating hybrid operation with priority for cooling even in winter. That is, the capability of the operation mode actually requested by the user can be appropriately provided, and the switching loss of the operation mode of the outdoor unit 2 accompanying the fluctuation of the request rate can be more effectively reduced.
In the above embodiment, the second threshold value and the third threshold value are set as the threshold value for defining the range of the outside air temperature in addition to the first threshold value, but the threshold value added to the first threshold value may be further increased. This allows the operation mode of the outdoor unit 2 to be switched in multiple stages, and the capability of the operation mode actually requested by the user can be provided more finely.
(embodiment mode 2)
Next, embodiment 2 will be explained. The structure itself of the air conditioner of embodiment 2 is the same as the structure of the air conditioner 1 of embodiment 1 shown in fig. 1 and 2.
Hereinafter, switching control of the operation modes (first mode, second mode) at the cooling operation and the heating operation in the air conditioner 1 of the present embodiment will be described.
Fig. 13 shows the relationship between the operation modes (first mode, second mode) and the target temperature of the heating agent during the cooling operation and the heating operation. This relationship is stored as a set value in a memory in the control unit 30. When the target temperature in the first mode (normal operation mode) is the target temperature TA1 during the cooling operation of the air conditioner 1, the target temperature in the second mode (energy saving operation mode) is the target temperature TA2 (> TA 1). That is, the target temperature of the second mode at the cooling operation is set higher than the target temperature of the first mode.
In the heating operation of the air conditioner 1, when the target temperature in the first mode (normal operation mode) is the target temperature TB1, the target temperature in the second mode (energy saving operation mode) is the target temperature TB2(< TB 1). That is, the target temperature of the second mode at the time of heating operation is set to be lower than the target temperature of the first mode. Here, the target temperatures TA1, TA2, TB1, TB2 of the heating agent can be set from the control panel 100, for example.
Next, the operation mode switching process performed by the control unit will be described. Fig. 14 shows a flowchart as an example of the switching process of the operation mode. In the present embodiment, a case will be described in which the control unit 30 of the heat exchange unit 3 executes main control and the control unit 20 executes rotation control of the compressor 2 a.
The control unit 30 determines whether the operation of the air conditioner 1 is the cooling operation or the heating operation, for example, based on an instruction from the control panel 100 (ST 101). If it is determined at step ST101 that the cooling operation is performed, control unit 30 determines the mode (ST 102). In the present embodiment, as described above, the mode is determined based on the instruction from the control panel 100. If it is determined that the mode is the first mode (normal operation mode), control unit 30 sets TA1 as the target temperature of the heating medium (ST 103). That is, the current operation state is continued. If it is determined that the mode is the second mode (energy saving operation mode), control unit 30 sets TA2 (> TA1) as the target temperature of the heating agent (ST 104). This changes the target temperature of the heating medium during the cooling operation.
On the other hand, if it is determined that the heating operation is performed in step ST101, the control unit 30 determines the mode (ST 105). The mode is determined based on the instruction from the control panel 100, which is the same as the case of the cooling operation. If it is determined that the mode is the first mode (normal operation mode), control unit 30 sets TB1 as the target temperature of the heating medium (ST 106). That is, the current operation state is continued. If it is determined that the mode is the second mode (energy saving operation mode), control unit 30 sets TB2(< TB1) as the target temperature of the heating agent (ST 107). Thereby, the target temperature of the heating agent during the heating operation is changed. Thus, after setting the target temperature of the heating agent, the control unit 20 operates the air conditioner 1 at the set target temperature (ST 108). That is, the control unit 20 controls the rotation speed of the compressor 2a so that the temperature currently acquired from the heating medium becomes the target temperature set for the heating medium.
Next, the operational effects of the air conditioner 1 will be explained.
When each indoor unit 5 performs a cooling operation, the rotation speed of the compressor 2a of the outdoor unit 2 is controlled in accordance with the target temperature of the heating medium set for the cooling intermediate heat exchanger 31 b. Therefore, the lower the target temperature of the heating agent, the greater the rotation speed of the compressor 2 a. For example, in the first mode (normal operation mode), the outlet set temperature of the cooling intermediate heat exchanger 31b, that is, the target temperature of the heating agent is set to 7 ℃, and in the energy saving operation mode, the outlet set temperature of the cooling intermediate heat exchanger 31b, that is, the target temperature of the heating agent is set to 12 ℃. As described above, by setting the target temperature of the heating agent higher in the second mode than in the first mode, the rotation speed of the compressor 2a of the outdoor unit 2 can be suppressed at the time of the second mode setting, so that energy consumption can be saved.
For example, when each indoor unit 5 performs a heating operation, the rotation speed of the compressor 2a of the outdoor unit 2 is controlled in accordance with the target temperature of the heating agent set for the intermediate heat exchanger 32b for heating. Therefore, the higher the target temperature of the heating agent, the greater the rotation speed of the compressor 2 a. For example, in the first mode (normal operation mode), the outlet set temperature of the heating intermediate heat exchanger 32b, that is, the target temperature of the heating agent is set to 45 ℃, and in the second mode (energy saving operation mode), the outlet set temperature of the heating intermediate heat exchanger 32b, that is, the target temperature of the heating agent is set to 40 ℃. In the second mode, by setting the target temperature of the heating agent to be low as compared with the first mode, the rotation speed of the compressor 2a of the outdoor unit 2 can be suppressed at the time of the second mode setting, so that energy consumption can be saved.
In the present embodiment, the operation mode can be changed from the control panel 100, that is, from the first mode (normal operation mode) to the second mode (energy saving operation mode). Therefore, for example, at the time of a power peak, the manager of the air conditioner 1 operates the control panel 100 to change the operation mode of the air conditioner 1 from the first mode to the second mode, thereby making it possible to suppress the amount of power consumption at the time of the peak. That is, the air conditioner 1 can save power consumption.
In the present embodiment, the case where the operation mode of the air conditioner 1 is changed by the administrator operating the control panel 100 has been described, but the method of changing the operation mode is not limited to this. For example, the control unit 30 is configured to change the operation mode of the air conditioner 1 from the first mode to the second mode according to the operation state of the indoor unit 5. Specifically, the control section 40 of the valve unit 4 communicates with the control section 50 of each indoor unit 5 connected to the valve unit 4, and acquires the operating condition of each indoor unit 5. The control unit 30 communicates with the control unit 40 of the valve unit 4 to acquire the operating state of each indoor unit 5, and when it is acquired that all the indoor units 5 are operated at the minimum capacity, the control unit 30 changes the operating mode of the air conditioner 1 from the first mode (normal operating mode) to the second mode (energy saving mode). Even in this case, as in the above-described embodiment, the rotational speed of the compressor 2a of the outdoor unit 2 can be suppressed, and energy consumption of the air conditioner 1 can be reduced. In addition, even if no instruction is issued from the control panel 100, the air conditioner 1 can automatically save power consumption.
In the present embodiment, the case where the pumps 5a are provided in the respective indoor units 5 has been described, but the pump positions may be provided not in the respective indoor units 5 but in the vicinity of the respective indoor units 5. For example, as in the third modification shown in fig. 15, even if no pump is provided in each indoor unit 5, a pump Pa for adjusting the flow rate of the heating medium for cooling and a pump Pb for adjusting the flow rate of the heating medium for heating may be provided between the heat exchange unit 3 and the valve unit 4. Fig. 15 shows an air conditioner 1c according to a third modification. The basic configuration of the air conditioner 1c is the same as that of the air conditioner 1 of embodiment 1 described above. Therefore, the same configurations as those of the air conditioner 1 are denoted by the same reference numerals in the drawings, and the description thereof is omitted.
(embodiment mode 3)
Next, embodiment 3 will be explained. The basic configuration of the air conditioner of embodiment 3 is the same as that of the air conditioner 1 of embodiment 1 shown in fig. 1 and 2. Therefore, the same configurations as those of the air conditioner 1 are denoted by the same reference numerals in the drawings, and the description thereof is omitted.
Embodiment 3 differs from embodiment 1 in the arrangement of the intermediate cooling heat exchanger 31b and the intermediate heating heat exchanger 32 b. Therefore, the arrangement of the cooling intermediate heat exchanger 31b and the heating intermediate heat exchanger 32b will be described in detail.
In the present embodiment, compact plate heat exchangers are used as the cooling intermediate heat exchanger 31b and the heating intermediate heat exchanger 32 b. The plate heat exchanger is generally designed such that the long side direction is a vertical direction and the short side direction is a horizontal direction, and the refrigerant flows in the long side direction. This is because the longitudinal direction is perpendicular, and the cross-sectional area of the flow path can be reduced, the flow velocity can be increased, and the thermal conductivity can be improved. Performance can be improved with the same volume as compared with the case where the short side direction is the vertical direction.
It is assumed that the heat exchange unit 3 is disposed in a narrow space such as a ceiling back surface. Therefore, the height direction (vertical direction) of the housing is preferably designed to be as small as possible. Therefore, as shown in fig. 16 and 17, the intermediate heat exchanger 31b for cooling and the intermediate heat exchanger 32b for heating are provided. In fig. 16 and 17, the lower side is a mounting surface G of the plate heat exchanger. In the present embodiment, the heat exchange unit 3 includes three small-sized intermediate heat exchangers 31b for cooling and one large-sized intermediate heat exchanger 32b for heating.
As shown in fig. 16, in the heat exchange unit 3, the intermediate heat exchanger for cooling 31b is provided such that the refrigerant flows in a vertical direction from below toward above with respect to the installation surface G. That is, the refrigerant flows into the inlet E11 as indicated by an arrow R1 in the figure and then flows out in a gas phase (gas) state from the outlet E12, with the inlet E11 of the refrigerant being located downward and the outlet E12 of the refrigerant being located upward on the installation surface G. Since the two-phase refrigerant (gas phase, liquid phase) flows into the cooling intermediate heat exchanger 31b, if it is installed in the horizontal direction with respect to the installation surface G (as in the heating intermediate heat exchanger 32b in fig. 17), the refrigerant liquid is biased downward, and therefore the plates in the cooling intermediate heat exchanger 31b cannot be effectively used, and the performance of the heat exchanger is greatly reduced, and there is a possibility that a problem such as freezing may occur due to a reduction in the evaporation temperature. Therefore, as shown in fig. 16, a cooling intermediate heat exchanger 31b is provided.
On the other hand, as shown in fig. 17, in the heat exchange unit 3, the intermediate heat exchanger for heating 32b is provided so that the refrigerant flows in the horizontal direction with respect to the installation surface G. That is, as indicated by an arrow R2, the refrigerant flows in from the inlet E21 and then flows out from the outlet E22. In the intermediate heat exchanger for heating 32b, the refrigerant flows in a gas-phase (gas) state and flows out in a refrigerant-liquid (condensate) state, and therefore, even if the refrigerant is provided to flow in the horizontal direction, the plates in the intermediate heat exchanger for heating 32b can be effectively used, and the performance of the heat exchanger can be suppressed from being lowered as compared with the intermediate heat exchanger for cooling 31 b. Therefore, as shown in fig. 17, a heating intermediate heat exchanger 32b is provided.
Therefore, as shown in fig. 16 and 17, by providing the intermediate heat exchanger 31b for cooling and the intermediate heat exchanger 32b for heating, a plurality of intermediate heat exchangers 31b for cooling are required, but since one intermediate heat exchanger 32b for heating can be provided, the cost of the intermediate heat exchanger can be reduced while suppressing the performance degradation of the air conditioner 1, and the manufacturing cost due to the increase of the number of parts and the increase of the number of welding parts can be suppressed.
In the present embodiment, the case where the number of the cooling intermediate heat exchangers 31b is 3 in the heat exchange unit 3 has been described, but the number of the cooling intermediate heat exchangers 31b is not limited to this. The number of the intermediate heat exchangers 31b for cooling and the number of the intermediate heat exchangers 32b for heating may be increased or decreased within a range of reducing the increase of the number of the welded portions and the number of the members as much as possible according to the environment such as the installation area of the place where the heat exchangers are installed and the height of the place where the heat exchangers are installed.
While the embodiments of the present invention have been described above, these embodiments are presented by way of example only, and are not intended to limit the scope of the invention. These new embodiments may be implemented in other various ways, and various omissions, substitutions, and changes may be made without departing from the scope of the invention. These embodiments and modifications are included in the scope and gist of the invention, and are also included in the invention described in the scope of the claims and the equivalent scope thereof.
Description of the reference symbols
1. 1a, 1b, 1c … air conditioner, 2 … outdoor unit, 2l … outside air temperature sensor, 3 … heat exchange unit, 3b … intermediate heat exchanger, 4 … valve unit, 4a … flow path switching valve, 5 … indoor unit, 5a … circulating pump, 5b … indoor side heat exchanger, 5d … information acquisition unit, 6 … refrigerant pipe, 6a … liquid pipe, 6b … suction gas pipe, 6c … discharge gas pipe, 7, 8 … heating agent pipe, 7a 2 cooling heating agent supply pipe, 7b … heating agent return pipe, 8a … heating agent supply pipe, 8b … heating agent return pipe, 9 … distribution pipe, 9a … water inlet pipe, 9b … water return pipe, 20, 30, 40, 50 … control unit, 21, 31, 41, 51 b … casing, 31b … cooling intermediate heat exchanger 5474, and … heating heat exchanger …, 31d, 32d, 34 … temperature sensors, 35 … pressure sensors, 41a … water inlet valves, 42a … water return valves, E11 and E21 … inlets, and E12 and E22 … outlets.

Claims (12)

1. An air conditioner, characterized by comprising:
an outdoor unit having a compressor for circulating a refrigerant, an outdoor-side heat exchanger, and a first expansion valve;
a heat exchange unit having a plurality of intermediate heat exchangers for exchanging heat between a refrigerant and a heating agent, and second expansion valves corresponding to the plurality of intermediate heat exchangers;
an indoor unit having an indoor-side heat exchanger for exchanging heat between the heating agent and indoor air;
a valve unit having a flow path switching valve for allowing either one of the refrigerant cooled by the intermediate heat exchanger and the refrigerant heated by the intermediate heat exchanger to flow into the indoor-side heat exchanger; and
a control unit having a control section for controlling each unit,
the outdoor unit, the heat exchange unit, the indoor unit, and the valve unit are respectively divided and formed with a housing,
the outdoor unit and the heat exchange unit are connected by a liquid pipe for feeding the condensate condensed by the outdoor heat exchanger to the heat exchange unit or feeding the condensate condensed by the intermediate heat exchanger to the outdoor unit, a suction gas pipe for feeding the refrigerant evaporated by the intermediate heat exchanger to the outdoor unit, and a discharge gas pipe for feeding the discharge gas compressed by the compressor to the heat exchange unit,
the control unit performs a heating operation by flowing the exhaust gas into the intermediate heat exchanger,
performing a cooling operation by condensing the exhaust gas in the outdoor heat exchanger and allowing the condensed condensate to flow into the intermediate heat exchanger via the second expansion valve,
a cooling-heating hybrid operation in which a part of the exhaust gas flows into one of the intermediate heat exchangers and is condensed, the other part of the exhaust gas flows into the outdoor heat exchanger and is condensed, the condensed condensate is mixed with the refrigerant condensed by the intermediate heat exchanger through the liquid pipe, and the mixed condensate flows into the other intermediate heat exchanger through the second expansion valve and is evaporated, thereby performing cooling-priority hybrid operation,
the exhaust gas is caused to flow into one of the plurality of intermediate heat exchangers and to condense, a part of the exhaust gas is caused to flow into the outdoor heat exchanger through the liquid pipe and to evaporate, and the remaining part of the condensate is caused to flow into the other intermediate heat exchanger through the second expansion valve and to evaporate, whereby a cooling-heating hybrid operation in which heating is prioritized is performed.
2. The air conditioner according to claim 1,
the pipe diameters of pipes connecting the outdoor unit and the heat exchange unit satisfy the following relationship: the suction gas pipe > the discharge gas pipe > the liquid pipe.
3. An air conditioner according to claim 2,
at least one of the plurality of intermediate heat exchangers is a cooling intermediate heat exchanger that cools the refrigerant during cooling operation, and the remaining intermediate heat exchangers are heating intermediate heat exchangers that heat the refrigerant during heating operation,
the exhaust gas pipe is connected to the intermediate heat exchanger for heating,
the suction gas pipe is connected to the intermediate heat exchanger for cooling,
the liquid pipe is connected to the heating intermediate heat exchanger and the cooling intermediate heat exchanger.
4. An air conditioner according to claim 3,
a third expansion valve is provided in the heat exchange unit,
the third expansion valve is provided between the suction gas pipe and the intermediate heat exchanger for cooling.
5. The air conditioner according to claim 4,
the third expansion valve operates based on an inlet temperature of the intermediate heat exchanger for cooling or an evaporation gas saturation temperature obtained by converting an outlet pressure of the intermediate heat exchanger for cooling to a saturation temperature.
6. The air conditioner according to claim 1,
the intermediate heat exchanger is a plate heat exchanger constructed by stacking plates,
the plurality of plate heat exchangers include a plurality of cooling intermediate heat exchangers for cooling the heating medium, and a number of heating intermediate heat exchangers for heating the refrigerant smaller than the number of the plurality of cooling intermediate heat exchangers,
the intermediate heat exchanger for cooling is disposed so that the refrigerant flows in a direction perpendicular to a mounting surface,
the intermediate heat exchanger for heating is provided so that the refrigerant flows in a horizontal direction with respect to an installation surface.
7. The air conditioner according to claim 1,
the outdoor unit has an outside air temperature sensor for detecting an outside air temperature,
the control unit selects any one of the heating operation, the cooling-priority cooling-heating hybrid operation, and the heating-priority cooling-heating hybrid operation based on a ratio of a cooling request or a heating request to the indoor unit and the outside air temperature detected by the outside air temperature sensor, and operates the outdoor unit.
8. An air conditioner according to claim 7,
the control unit sets the outside air temperature detected by the outside air temperature sensor TO TO, a first predetermined temperature defining a range of the outside air temperature TO TH, and a second predetermined temperature TO TL,
switching the outdoor unit from the cooling-priority cooling-heating hybrid operation TO the heating-priority cooling-heating hybrid operation if a ratio of heating requests TO the indoor units is equal TO or greater than a first threshold when TL < TO < TH, and switching the outdoor unit from the heating-priority cooling-heating hybrid operation TO the cooling-priority cooling-heating hybrid operation if a ratio of cooling requests TO the indoor units is equal TO or greater than a first threshold when the outdoor unit performs the heating-priority cooling-heating hybrid operation,
if the TO is equal TO or greater than TH, if the outdoor unit performs the cooling-heating hybrid operation with priority for cooling, the outdoor unit continues TO perform the cooling-heating hybrid operation with priority for cooling even if the ratio of the heating requests TO the indoor units is equal TO or greater than the first threshold value,
if the TO is equal TO or less than TL, if the outdoor unit performs the cooling-heating hybrid operation with priority on heating, the outdoor unit continues TO perform the cooling-heating hybrid operation with priority on heating even if the ratio of the cooling requests TO the indoor units is equal TO or greater than the first threshold value.
9. The air conditioner according to claim 8,
the control unit switches the outdoor unit from the cooling-priority cooling-heating hybrid operation TO the heating-priority cooling-heating hybrid operation if the ratio of the heating requests TO the indoor units is equal TO or greater than a second threshold value that is greater than a first threshold value when TO is equal TO or greater than TH,
and switching the outdoor unit from the heating-prioritized cooling-heating hybrid operation TO the cooling-prioritized cooling-heating hybrid operation if a ratio of cooling requests TO the indoor units is greater than or equal TO a third threshold value that is greater than the first threshold value, in a case where TO is equal TO or less than TL.
10. The air conditioner according to claim 1,
the heat exchange unit has a temperature sensor for detecting a temperature of the heating agent on a downstream side of the intermediate heat exchanger,
the control unit stores a setting of a target temperature of the heating agent in each operation mode of a cooling operation and a heating operation, and acquires the temperature of the heating agent detected by the temperature sensor, controls a rotation speed of the compressor based on the acquired temperature and the target temperature,
the operation mode has a first mode and a second mode operating in a power-saving manner with respect to the first mode,
the target temperature of the second mode at the cooling operation is set higher than the target temperature of the first mode, and the target temperature of the second mode at the heating operation is set lower than the target temperature of the first mode.
11. An air conditioner according to claim 10,
the outdoor unit is connected to a control panel,
the air conditioner shifts from the first mode to the second mode based on an instruction of the control panel.
12. An air conditioner according to claim 10,
the valve unit includes a communication unit for communicating with a plurality of the indoor units connected thereto, respectively,
the control unit acquires the operating states of the plurality of indoor units via the valve unit, and shifts the air conditioner from the first mode to the second mode based on the acquired operating states of the plurality of indoor units.
CN202080065478.6A 2019-09-17 2020-06-26 Air conditioner Active CN114466995B (en)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
JP2019168316 2019-09-17
JP2019168319 2019-09-17
JP2019-168317 2019-09-17
JP2019168317 2019-09-17
JP2019-168316 2019-09-17
JP2019-168319 2019-09-17
PCT/JP2020/025338 WO2021053924A1 (en) 2019-09-17 2020-06-26 Air conditioner

Publications (2)

Publication Number Publication Date
CN114466995A true CN114466995A (en) 2022-05-10
CN114466995B CN114466995B (en) 2023-08-15

Family

ID=74884185

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202080065478.6A Active CN114466995B (en) 2019-09-17 2020-06-26 Air conditioner

Country Status (5)

Country Link
US (1) US20220205671A1 (en)
EP (1) EP4033177A4 (en)
JP (1) JP7356506B2 (en)
CN (1) CN114466995B (en)
WO (1) WO2021053924A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2022164260A (en) * 2021-04-16 2022-10-27 株式会社デンソー Refrigeration cycle device
JP7398582B1 (en) 2023-02-16 2023-12-14 東芝キヤリア株式会社 air conditioner

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06294551A (en) * 1993-04-06 1994-10-21 Hitachi Ltd Airconditioning apparatus
WO2010050006A1 (en) * 2008-10-29 2010-05-06 三菱電機株式会社 Air conditioner
CN203203199U (en) * 2012-03-27 2013-09-18 三菱电机株式会社 Air conditioning device
JP2016125724A (en) * 2014-12-26 2016-07-11 ダイキン工業株式会社 Heat storage type air conditioner
WO2016194145A1 (en) * 2015-06-02 2016-12-08 三菱電機株式会社 Air-conditioning device
WO2018105250A1 (en) * 2016-12-09 2018-06-14 ダイキン工業株式会社 Air conditioning apparatus

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5236009B2 (en) 1973-10-25 1977-09-13
KR100619775B1 (en) * 2005-02-15 2006-09-11 엘지전자 주식회사 Multi-air conditioner capable of cooling and heating simultaneously
US20120031130A1 (en) * 2009-04-17 2012-02-09 Mitsubishi Electric Corporation Relay unit and air conditioning apparatus
EP2431675B1 (en) * 2009-05-12 2019-09-11 Mitsubishi Electric Corporation Air conditioner
CN103975202B (en) * 2012-01-05 2016-09-14 三菱电机株式会社 Air-conditioning device
JP2017101855A (en) * 2015-11-30 2017-06-08 株式会社富士通ゼネラル Air conditioning system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06294551A (en) * 1993-04-06 1994-10-21 Hitachi Ltd Airconditioning apparatus
WO2010050006A1 (en) * 2008-10-29 2010-05-06 三菱電機株式会社 Air conditioner
CN203203199U (en) * 2012-03-27 2013-09-18 三菱电机株式会社 Air conditioning device
JP2016125724A (en) * 2014-12-26 2016-07-11 ダイキン工業株式会社 Heat storage type air conditioner
WO2016194145A1 (en) * 2015-06-02 2016-12-08 三菱電機株式会社 Air-conditioning device
WO2018105250A1 (en) * 2016-12-09 2018-06-14 ダイキン工業株式会社 Air conditioning apparatus

Also Published As

Publication number Publication date
JP7356506B2 (en) 2023-10-04
US20220205671A1 (en) 2022-06-30
JPWO2021053924A1 (en) 2021-03-25
EP4033177A1 (en) 2022-07-27
EP4033177A4 (en) 2024-01-24
CN114466995B (en) 2023-08-15
WO2021053924A1 (en) 2021-03-25

Similar Documents

Publication Publication Date Title
JP5474050B2 (en) Air conditioner
JP6072077B2 (en) Air conditioner
US10393419B2 (en) Air-conditioning apparatus
US8950202B2 (en) Heat pump system
JP5933031B2 (en) Air conditioner
JP5921719B2 (en) Air conditioner
JP5774128B2 (en) Air conditioner
US9494361B2 (en) Air-conditioning apparatus with improved defrost operation mode
KR102330339B1 (en) Multi-type air conditioner and control method for the same
JPWO2011089652A1 (en) Air conditioning and hot water supply complex system
CN114466995B (en) Air conditioner
US11112151B2 (en) Heat source unit for refrigeration apparatus including a heat-source-side heat exchanger having a heat exchange region of variable size
KR101702178B1 (en) Chiller system
CN113439188A (en) Air conditioner
JP7360285B2 (en) air conditioner
US20190011157A1 (en) Air conditioning apparatus
JP2021046952A (en) Air conditioner
KR102390900B1 (en) Multi-type air conditioner and control method for the same
JP6336066B2 (en) Air conditioner
JP7258129B2 (en) air conditioner
JP7438342B2 (en) air conditioner
JP7055239B2 (en) Air conditioner

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant