CN114466995B - Air conditioner - Google Patents

Air conditioner Download PDF

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Publication number
CN114466995B
CN114466995B CN202080065478.6A CN202080065478A CN114466995B CN 114466995 B CN114466995 B CN 114466995B CN 202080065478 A CN202080065478 A CN 202080065478A CN 114466995 B CN114466995 B CN 114466995B
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CN
China
Prior art keywords
heating
cooling
heat exchanger
unit
intermediate heat
Prior art date
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Active
Application number
CN202080065478.6A
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Chinese (zh)
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CN114466995A (en
Inventor
滨岛哲磨
木口行雄
浅利峻
有田照平
三浦贤
清水智纪
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Toshiba Carrier Corp
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Toshiba Carrier Corp
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Publication of CN114466995A publication Critical patent/CN114466995A/en
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Classifications

    • 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
    • F24F11/62—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
    • 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

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  • 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, mixes the condensed condensate with refrigerant condensed in the intermediate heat exchanger through a liquid pipe, causes the mixed condensate to flow into the other intermediate heat exchanger through a second expansion valve and evaporate, thereby performing a cooling-heating mixing operation with priority of cooling, causes the exhaust gas to flow into one of the plurality of intermediate heat exchangers and condense, causes a part of the exhaust gas to flow into the outdoor side heat exchanger through the liquid pipe and evaporate, and causes the remaining part of the condensate to flow into the other intermediate heat exchanger through a second expansion valve and evaporate, thereby performing a cooling-heating mixing operation with priority of heating.

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 restricted in stages, starting from the european amendment of fluorine gas regulations. Accordingly, development of air conditioners using a refrigerant having a low GWP is being advanced, and R410A, which is the main stream in home air conditioners and commercial air conditioners, has been replaced with R32.
On the other hand, R32 is a micro-flammable (A2L) refrigerant, and for example, when used in a Variable Refrigerant Flow (VRF) type air conditioner having a large refrigerant charge amount, safety in the case of leakage into the room needs to be considered. Accordingly, although the VRF air conditioner continues to use R410A, according to recent research and development, a system has been proposed in which water is circulated as a heating agent to cool and heat an indoor unit alone. As an example, in the air conditioner of this type, the relay unit is provided between the outdoor unit and the 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, refrigerant piping passes from the outdoor unit to the relay unit, and water piping passes between the relay unit and the indoor unit. Thus, safety can be ensured against leakage of the refrigerant in the room, and a slightly flammable refrigerant such as R32 can be used.
Prior art literature
Patent literature
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 described above, the flow path is appropriately switched by the flow path switching valve so that cold water is circulated in the indoor unit requesting cooling operation and hot water is circulated in the indoor unit requesting heating operation. When the air conditioner is operated in a mode of mixing cooling and heating (cooling and heating mixing 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 equal to or greater than half, the outdoor units perform the cooling/heating hybrid operation in which the cooling is prioritized. In contrast, when the ratio of the heating requests to the indoor units is equal to or greater than half, the outdoor units perform the cooling/heating hybrid operation in which the heating is prioritized. Thus, when the operation mode of the outdoor unit is switched, the capability of the indoor unit to be predicted as requiring a large number of operation modes, such as cooling in summer and heating in winter, may be reduced in response to a change in the ratio of the setting request. In addition, with switching of the operation mode of the outdoor unit, a swing in the circulation state may occur.
The present invention has been made in view of the above-described circumstances, and a first object thereof is to provide a water circulation type air conditioner capable of suppressing a decrease in capacity predicted to request a large number of operation modes and occurrence of hunting in a circulation state.
In the air conditioner described above, the rotation speed of the compressor provided in the outdoor unit is controlled based on the temperature of the heating agent on the downstream side of the heating agent in the intermediate heat exchanger. At this time, the target heating agent temperature of the intermediate heat exchanger is 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, thereby using energy exceeding that required.
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.
In addition, in the above air conditioner, for example, when the cooling and heating hybrid 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 the outdoor exchanger. This is because, when the cooling/heating hybrid operation with heating prioritized is performed in winter, since the outdoor heat exchanger is an evaporator, the pressure of the refrigerant flowing through the intermediate heat exchanger for cooling is led to the outdoor heat exchanger side, and the evaporation temperature is lowered. In this case, when the refrigerant is water, the intermediate heat exchanger for cooling may be frozen, and therefore, it is necessary to prevent this freezing.
In the air conditioner described above, water circulates in each indoor unit. Therefore, it is necessary to consider piping resistance due to the flow path length of water so that the water flow rate of each indoor unit does not vary. As a countermeasure for this, for example, a flow control valve for each indoor unit is disposed in the relay unit, but in this case, the size of the housing of the relay unit, the cost, and the like are easily increased. In particular, when the heat discharged from the outdoor unit is used as heat recovery, a water heat exchanger and a flow path switching valve, a circulation pump, and even a flow rate regulating valve, each of which has a capacity corresponding to the VRF, need to be housed in the relay unit. As a result, there is a possibility that the housing size of the relay unit further increases, and the number of personnel for installation work increases, and the installation space is ensured.
In the air conditioner described above, the cooling-dedicated operation or the heating-dedicated operation can be performed using two heat exchangers, but when the relay unit is installed in a small space such as the back surface of a ceiling, for example, the height method of the relay unit is limited in size, and it is necessary to use a plurality of small heat exchangers to construct the cooling-dedicated heat exchanger or the heating-dedicated heat exchanger. In this case, the cost of the single body of the intermediate heat exchanger is also increased, and the manufacturing cost is also increased due to the increase in the number of parts and the increase in the number of welded parts.
The present invention has been made in view of the above circumstances, and a third object thereof is to provide a water circulation type air conditioner capable of preventing freezing of an intermediate heat exchanger for cooling.
A fourth object of the present invention is to provide a circulating air conditioner that can reduce manufacturing costs.
Technical means for solving the technical 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 heat exchanging the refrigerant and the 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 heat-exchanging the heating agent and indoor air. The valve unit has a flow path switching valve for allowing either the heating agent cooled by the intermediate heat exchanger or the heating agent heated to flow into the indoor side heat exchanger. The control unit has a control portion for controlling each unit, the outdoor unit, the heat exchange unit, the indoor unit, and the valve unit are divided and formed with housings, respectively. The outdoor unit and the heat exchange unit are connected by a liquid pipe that conveys the condensate condensed by the outdoor side 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 a heating operation, a cooling-heating mixture operation with a cooling priority, and a cooling-heating mixture with a heating priority. During 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 exhaust gas at the outdoor side 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 with priority of cooling, the control unit causes a part of the exhaust gas to flow into one of the plurality of intermediate heat exchangers and condense, causes the remaining part of the exhaust gas to condense through the outdoor side heat exchanger, causes the condensed condensate to mix with the refrigerant condensed by the intermediate heat exchanger through the liquid pipe, and causes the mixed condensate to flow into the other intermediate heat exchanger through the second expansion valve and evaporate. In the heating-prioritized cooling/heating mixing operation, the control unit causes the exhaust gas to flow into one of the plurality of intermediate heat exchangers and condense, causes a part of the exhaust gas to flow into the outdoor-side heat exchanger through the liquid pipe and evaporate, and causes 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 the air conditioner according to embodiment 1.
Fig. 3 is a diagram schematically showing an example of the arrangement of each unit of the air conditioner according to embodiment 1.
Fig. 4A is a diagram schematically showing a piping system of a heat source side refrigeration cycle in a cooling/heating mixing operation of the air conditioner according to embodiment 1.
Fig. 4B is a mollier diagram of a heat source side refrigeration cycle in the cooling/heating hybrid operation of the air conditioner according to embodiment 1.
FIG. 5 is a graph showing the refrigerant density (kg/m) of embodiment 1 3 ) Ratio (%), refrigerant flow rate (m/s), (refrigerant flow rate) 2 A ratio (%) and a relationship between 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 chart showing operation mode selection processing of an outdoor unit in the air conditioner according to embodiment 1.
Fig. 8 is a control flow chart showing a summer operation mode selection process of an outdoor unit in the air conditioner of embodiment 1.
Fig. 9 is a control flow chart showing winter operation mode selection processing of the outdoor unit in the air conditioner of embodiment 1.
Fig. 10 is a control flow chart showing the intermediate-period operation mode selection process of the outdoor unit in the air conditioner of embodiment 1.
Fig. 11 is a diagram showing an example of a change in the ratio of a cooling request to an indoor unit and a heating request with time 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 corresponding to the outside air temperature at an intermediate time when the ratio of the cooling request to the heating request is changed in the air conditioner according to embodiment 1 as shown in fig. 11.
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 is changed 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 according to the outside air temperature in winter when the ratio of the cooling request to the heating request is changed as shown in fig. 11 in the air conditioner according to embodiment 1.
Fig. 13 is a graph showing a relationship between the operation modes at the time of cooling operation and at the time of heating operation of embodiment 2 and the target temperature of the heating agent.
Fig. 14 is a control flow chart showing one example of the switching processing of this operation mode of 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 heat exchanger for cooling 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 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 the air conditioner according to the present embodiment. Fig. 3 schematically shows an example of the arrangement 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 each unit is provided with a housing, and the units are connected by predetermined pipes 6 to 9. Among 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 or the like of each floor 1F, 2F of the building B. The ceiling space CS is a space defined between a beam on the back surface of the ceiling of the building B and the ceiling, for example. Fig. 1, 2, and 3 schematically show an air conditioner 1, and the number of units and the number of pipes can be appropriately increased or decreased from the illustrated embodiments.
These units 2, 3, 4, 5 are provided with control units 20, 30, 40, 50 for controlling the operations of the constituent elements described later. The control units 20, 30, 40, 50 constitute control means of the air conditioner 1, and each include 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, the respective control units 20, 30, 40, 50 read various data by the input/output circuits, perform arithmetic processing by the CPU by using a program read from the storage device to the memory, and perform operation control of the respective unit constituent elements based on the processing results. At this time, the control sections 20, 30, 40, 50 transmit and receive control signals to and from the respective unit constituent elements and each other by wire or wireless.
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 operations of the air conditioner can be set and adjusted by the manager (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 manager operating the control panel 100.
The control unit 30 of the heat exchange unit 3 stores the target temperature setting of the heating agent in each of the cooling operation mode and the heating operation mode, 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 agent 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 energy-saving operation mode) in which operation is performed with less power than the first mode.
The outdoor unit 2 and the heat exchange unit 3 constitute a heat source side refrigeration cycle that circulates a refrigerant in the air conditioner 1. The heat exchange unit 3, the valve unit 4, and the indoor unit 5 constitute a heating agent 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 6c.
The outdoor unit 2 includes, as main parts, 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 reservoir 2i, opening and closing valves 2j, 2k, and an outside air temperature sensor 2l. The outdoor unit fan 2h and the outside air temperature sensor 2l are connected to the inside of the casing 21 by pipes, and are disposed in the refrigerant flow paths circulating with the heat exchange unit 3, respectively. The outdoor unit fan 2h is provided adjacent to the outdoor heat exchanger 2e in a wall portion of the casing 21. The casing 21 defines the outline of the outdoor unit 2.
The heat exchange unit 3 is configured such that expansion valves 3a, 31a, 32a, 33a, intermediate heat exchangers 3b, 31b, 32b, an on-off valve 3c, and temperature sensors 3d, 31d, 32d are accommodated in a casing 31 as main parts, respectively. The housing 31 defines the outline of the heat exchange unit 3. The expansion valves 31a and 32a correspond to a second expansion valve facing the expansion valve 2f (first expansion valve) provided in the outdoor unit 2, and the expansion valve 33a corresponds to a third expansion valve facing the expansion valve 2 f. The intermediate heat exchanger 3b exchanges heat between the refrigerant and the heating agent. In the present embodiment, the heat exchange unit 3 includes a plurality of intermediate heat exchangers 3b, and at least one of the intermediate heat exchangers 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 also be an antifreeze solution. The temperature sensor 3d is provided on the downstream side of the intermediate heat exchanger 3b, and detects the temperature of the heating agent 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 intermediate heat exchanger 31b for cooling and the intermediate heat exchanger 32b for heating, the air conditioner 1 can perform either one or both of the cooling operation and the heating operation.
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, in the outdoor unit 2 and the heat exchange unit 3, the control sections 40 and 50 and the control sections 20 and 30 of the valve unit 4 and the indoor unit 5 appropriately transmit and receive control signals, and the constituent elements of the respective units 2 and 3 are operated.
In 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 in the gas refrigerant from the suction port 21a, compresses the sucked gas refrigerant, and discharges the gas refrigerant from the discharge port 22 a. The compressor 2a is a device that compresses a refrigerant to be in a high-temperature and high-pressure state, and is, for example, a capacity-controllable inverter compressor or the like. 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 heat exchanger 2e. At this time, a part of the gas refrigerant is branched by the four-way valve 2d and flows into the outdoor heat exchanger 2e. The gas refrigerant flowing in is radiated to the outside air through the outdoor heat exchanger 2e, condensed and liquefied. The outdoor heat exchanger 2e performs heat exchange between the refrigerant and the outside air, and functions as a condenser at the time of cooling operation. The liquefied refrigerant (condensate) is depressurized 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 sucks outside air into the casing 21 and flows into the outdoor side heat exchanger 2e, and then discharges outside the casing 21.
In the heat exchange unit 3, the supplied liquid refrigerant (condensate) is expanded through the cooling expansion valve 31a and flows into the cooling intermediate heat exchanger 31b. The inflowing liquid refrigerant absorbs heat from the heating agent through the intermediate heat exchanger 31b for cooling, and evaporates and vaporizes. The vaporized refrigerant (vapor gas) returns to the outdoor unit 2 through the expansion valve 33a for pressure control and the suction gas pipe 6 b. The vapor gas is defined as a refrigerant passing through the intermediate heat exchanger 31b for cooling and passing through the evaporation process. The vapor gas also includes, for example, a refrigerant that does not completely evaporate, 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 agent.
The vapor gas returned to the outdoor unit 2 is separated into a gas refrigerant and a liquid refrigerant in the memory 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 memory 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 on-off valve 2j is opened, and the gas refrigerant (exhaust gas) is supplied to the heat exchange unit 3 through the exhaust gas pipe 6 c.
In the heat exchange unit 3, the on-off valve 3c is opened, and the supplied gas refrigerant is cooled by the intermediate heat exchanger 32b for heating to the heating agent, 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 on-off valve 2k is opened, and the liquid refrigerant (condensate) returned to the outdoor unit 2 is expanded via the liquid tank 2g via the expansion valve 2f and flows into the outdoor heat exchanger 2e. The liquid refrigerant after inflow absorbs heat from the outside air through the outdoor side heat exchanger 2e and evaporates and vaporizes. During the heating operation, the outdoor heat exchanger 2e functions as an evaporator. At this time, the outdoor unit fan 2h sucks outside air into the casing 21, causes the outside air to flow into the outdoor side heat exchanger 2e, and then discharges the outside air to the outside 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 compressed again.
When the cooling and heating hybrid operation 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 (discharge gas) discharged from the compressor 2a is supplied to the heat exchange unit 3 through the discharge gas pipe 6c in the same manner as in the heating operation. In the heat exchange unit 3, similarly to the heating operation, the supplied gas refrigerant is condensed and liquefied by radiating heat to the heating medium through the intermediate heat exchanger 32b for heating. The liquefied refrigerant (condensate) is expanded by the heating expansion valve 32a and the cooling expansion valve 31a, respectively, and flows into the cooling intermediate heat exchanger 31b. The inflowing liquid refrigerant (condensate) absorbs heat from the heating agent through 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 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/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/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 agent 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 units 4 are connected to the heat exchange unit 3 via heating agent pipes 7, 8, respectively.
The heating agent pipe 7 constitutes a flow path of a heating agent (hereinafter referred to as a cooling heating agent) cooled by the intermediate heat exchanger 31b for cooling. The coolant piping 7 includes a coolant supply pipe 7a and a coolant return pipe 7b. The cooling-refrigerant supply pipe 7a is a flow path for supplying the cooling-refrigerant from the heat exchange unit 3 to the valve unit 4. The cooling-refrigerant return pipe 7b is a flow path for returning the cooling-refrigerant from the valve unit 4 to the heat exchange unit 3.
The heating agent pipe 8 constitutes a flow path of a heating agent (hereinafter referred to as a heating agent) heated by the intermediate heat exchanger 32b for heating. The heating agent pipe 8 includes a heating agent supply pipe 8a and a heating agent return pipe 8b. The heating agent supply pipe 8a is a flow path for supplying the heating agent from the heat exchange unit 3 to the valve unit 4. The heating-agent return pipe 8b is a flow path for returning the heating agent 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 to supply the heating agent to the indoor unit 5 and a water return pipe 9b to return the heating agent to the valve unit 4. The water inlet pipe 9a forms a flow path for supplying the cooling heating agent supplied from the cooling heating agent supply pipe 7a and the heating agent supplied from the heating agent supply pipe 8a to the indoor unit 5. The return pipe 9b constitutes a flow path for returning the cooling heating agent and the heating agent to the valve unit 4.
Accordingly, the cooling heating agent and the heating agent circulate 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 in the four water inlet pipes 9a, respectively, and the cooling heating agent and the heating agent are distributed to the four indoor units 5, respectively. The distributed cooling heating agent and heating agent are returned from the four return pipes 9b to the valve unit 4, respectively, and circulated between the valve unit and the heat exchange unit 3 through the cooling heating agent return pipe 7b or the heating agent return pipe 8b.
Therefore, the heating agent pipes 7 and 8 and the distribution pipe 9 have different pipe diameters. In the present embodiment, as an example, the pipe diameters of the cooling-agent supply pipe 7a and the cooling-agent return pipe 7b are larger than the pipe diameter of the water intake pipe 9 a. The pipe diameters of the heating agent supply pipe 8a and the heating agent return pipe 8b are larger than the pipe diameter of the return pipe 9 b. Therefore, the heating agent can be circulated smoothly and stably between the heating agent pipes 7, 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 units 5. Since each capacity (capacity) of the indoor unit 5 has a different design flow rate, the rated flow rate is obtained by using each capacity. If indoor units of 0.5HP to 5HP are used as series, the rated flow rates thereof are different from each other, and it is considered that the circulation pump 5a also requires about 3 series. In the present embodiment, the case where the heating agent flow path is circulated as a closed circuit is assumed, but the pipe flow rate is set to an appropriate value in consideration of air invasion caused by foreign matter mixing, water leakage, or the like. Therefore, the pipe diameters of the heating agent pipes 7 and 8 differ according to the total connection capacity of the indoor units 5.
The valve unit 4 is configured to house the flow path switching valve 4a as a main part in the case 41. The flow path switching valve 4a is a valve for allowing either one of the cooling heating agent and the heating agent 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 42a. The water inlet valve 41a and the water return valve 42a are three-way valves opened and closed by the control section 40, details of which will be described later. The housing 41 defines the outline of the valve unit 4.
The indoor unit 5 includes a circulation pump 5a, an indoor side heat exchanger 5b, an indoor unit fan 5c, and an information acquisition section 5d as main parts. The circulation pump 5a and the indoor heat exchanger 5b are connected by piping in the casing 51, and are disposed in the heating agent flow path circulating between the valve unit 4 and the heat exchange unit 3, respectively. The indoor unit fan 5c and the information acquisition unit 5d are disposed adjacent to the wall 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 a user, and is, for example, a panel for operation, a switch, a button, a display for display, or the like. The information acquisition unit 5d acquires information (data) such as the start of operation of the indoor unit 5, mode selection of cooling operation and heating operation, setting of indoor temperature, and the like, and supplies the acquired information to the control unit 50.
The following describes a heating agent flow path cycle constituted by the heat exchange unit 3, the valve unit 4, and the indoor unit 5.
In the refrigerant flow path cycle, the intermediate heat exchanger 31b for cooling of the heat exchange unit 3 radiates heat to the refrigerant, and the cooled refrigerant (cooling refrigerant) is supplied from the cooling refrigerant supply pipe 7a to the valve unit 4. Further, the intermediate heat exchanger 32b absorbs heat from the refrigerant and supplies the heated heating agent (heating agent) 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 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 water inlet valve 41a is connected to the cooling heating agent supply pipe 7a, and the cooling heating agent is supplied to the indoor unit 5 that performs the cooling operation. On the other hand, the flow path of the valve unit 4 is switched so that the water inlet valve 41a is connected to the heating agent supply pipe 8a, thereby supplying the heating agent to the indoor unit 5 performing the heating operation. The control section 50 switches between the cooling operation and the heating operation in the indoor unit 5 in accordance with, for example, the user's selection of the operation mode or the like acquired by the information acquisition section 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 water return valve 42a operates in correspondence with the water inlet valve 41a on the same flow path, and returns the heating agent supplied to the indoor unit 5 to the valve unit 4. Specifically, the water return valve 42a switches the flow path of the valve unit 4 so that the heating agent returned from the indoor unit 5 that performs the cooling operation is guided to the cooling heating agent return pipe 7b. The heating agent guided to the cooling heating agent return pipe 7b radiates heat to the refrigerant through the cooling intermediate heat exchanger 31b and is cooled again. On the other hand, the water return valve 42a switches the flow path of the valve unit 4 so that the heating agent returned from the indoor unit 5 performing the heating operation is guided to the heating agent return pipe 8b. The heating agent guided to the heating agent return pipe 8b absorbs heat from the refrigerant through the heating intermediate heat exchanger 32b and is heated again.
In the indoor unit 5, the circulation pump 5a operates in response to the operation or stop of the indoor unit 5, and sucks in the cooling heating agent or the heating agent and discharges the cooling heating agent to the indoor side heat exchanger 5b. The circulation pump 5a is an inverter type pump capable of increasing or decreasing the rotation speed, and increases or decreases the rotation speed based on, for example, the outlet temperature of the heating agent (outlet water temperature of the indoor side heat exchanger 5 b). The indoor heat exchanger 5b exchanges heat between indoor air and a heating agent to adjust the temperature. The indoor unit fan 5c sucks in indoor air into the casing 51, causes the indoor air to flow into the indoor heat exchanger 5b, and then blows the temperature-regulated air from the casing 51 toward the space to be air-conditioned. The indoor-unit fan 5c rotates almost simultaneously with the operation start request for cooling or heating and stops almost simultaneously with the operation stop request. The order of stopping the circulation pump 5a and the indoor unit fan 5c may be either one of stopping first. As one example, from the standpoint of sensing the indoor temperature, it is desirable to first stop the circulation pump 5a and continue rotating 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 mixture operation with priority of cooling, and the cooling/heating mixture operation with priority of heating. For example, 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.
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 intermediate heat exchanger 31b for cooling via the expansion valve 31a for cooling.
The heating operation is an operation mode in which the exhaust gas of the compressor 2a flows into the intermediate heat exchanger for heating 32 b.
The cooling-heating hybrid operation in which cooling is prioritized is an operation mode in which the cooling operation and the heating operation are performed in a hybrid manner, but the cooling operation is performed appropriately in priority. In the cooling/heating mixing operation with priority of cooling, a part of the discharge gas of the compressor 2a flows into the intermediate heat exchanger for heating 32b and is condensed, and the remaining part of the discharge gas is condensed by the outdoor heat exchanger 2 e. The condensate of the two is mixed, and the mixed condensate flows into the intermediate heat exchanger 31b for cooling through the expansion valve 31a for cooling and is evaporated.
The heating-prioritized cooling-heating hybrid operation is an operation mode in which the cooling operation and the heating operation are performed in a hybrid manner, but the heating operation is performed preferentially and appropriately. In the cooling/heating mixing operation in which heating is prioritized, the exhaust gas of the compressor 2a flows into the intermediate heat exchanger for heating 32b and is condensed. Part of the condensate flows into the outdoor heat exchanger 2e through the liquid pipe 6a and is evaporated. The remaining portion 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 at the time of these cooling-heating hybrid 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, P1 to P2 represent a state change of the refrigerant at the compressor 2a, P2 to P3 represent a state change of the refrigerant at the outdoor side heat exchanger 2e (condenser), P3a to P4 represent a state change of the refrigerant at the cooling expansion valve 31a, P4 to P5 represent a state change of the refrigerant at the cooling intermediate heat exchanger 31B, and P5 to P1 represent a state change of the refrigerant at the pressure control expansion valve 33 a. In fig. 4B, P3B to P6 represent changes in the state of the refrigerant at the heating expansion valve 32a and the expansion valve 2f, and P6 to P7 (P1) represent changes in the state of the refrigerant at the outdoor side heat exchanger 2e (evaporator). P1 to P7 shown by the left white points 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, in general, the pressure loss dP of the refrigerant can be obtained by the following expressions (1) and (2).
[ mathematics 1]
dP＝p×g×dH…(1)
[ math figure 2]
Here, dP is the pressure loss, dH is the total head loss, g is the gravitational acceleration, ρ is the fluid density, λ is the tube friction coefficient, l is the tube length, d is the tube inner diameter, and ν is the average flow velocity in the tube. In addition, in the case of the optical fiber,
[ math 3]
Is a coefficient for various losses other than friction.
As is clear from the above equations (1) and (2), when the pipe diameter d is fixed, the influence on the pressure loss dP is that the influence of the pipe friction coefficient λ, the fluid density ρ, and the average flow velocity ν in the pipe becomes large.
Here, in the present embodiment, when the discharge gas pipe 6c, the liquid pipe 6a, and the suction gas pipe 6b are fixed to have a fixed pipe diameter d, one example of the refrigerant density and the refrigerant flow rate is shown in table T1 of fig. 5. In addition, the pressure loss ratio is refrigerant density× (refrigerant flow rate) 2 Is a ratio of (2).
The refrigerant density (kg/m) is shown in FIG. 5 3 ) Ratio (%), refrigerant flow rate (m/s), (refrigerant flow rate) 2 The ratio (%) and the compression ratio, and the discharge gas pipe, the liquid pipe, and the suction gas pipe. As shown in fig. 5, the refrigerant density is "94.2" for the discharge gas piping, "980.4" for the liquid piping, "34.6" for the suction gas piping, and the ratio is "100" for the discharge gas piping, "1041" for the liquid piping, and "37" for the suction gas piping. The refrigerant flow rates are the discharge gas piping "23.3", the liquid piping "2.2", and the suction gas piping "63.4", the pressure loss is the discharge gas piping "542.4", the liquid piping "5.0", the suction gas piping "4025.7", and the ratios are the discharge gas piping "100", the liquid piping "10", and the 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 so that the suction gas pipe 6b > the discharge gas pipe 6c > the liquid pipe 6a. Thus, the air conditioner 1 can be made an efficient and excellent system by constituting the pipe diameter d of the air conditioner 1.
In fig. 4A, when the heating load is large, the outdoor side heat exchanger 2e needs to function as an evaporator. Therefore, for example, when the outside air temperature in winter is 0 ℃, the outdoor side heat exchanger 2e absorbs heat from the outside air, and therefore the evaporation temperature of the outdoor side heat exchanger 2e is a temperature of about-10 ℃.
Here, it is assumed that the air conditioner 1 does not have the expansion valve (intermediate pressure control expansion valve) 33a in fig. 4A, and the evaporation temperature of the intermediate heat exchanger 31b for cooling becomes substantially the same temperature as the outdoor side heat exchanger 2 e. Therefore, when water is used as the heating agent, the intermediate heat exchanger 31b for cooling may freeze and crack (actually, the evaporation temperature of the intermediate heat exchanger for cooling may slightly increase in accordance with the piping pressure loss).
Therefore, the air conditioner 1a according to the first modification shown in fig. 6A includes a temperature sensor 34 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. Based on the temperature detected by the temperature sensor 34, the control unit 30 performs control of opening and closing the expansion valve 33 a. 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 a plate heat exchanger used as an evaporator may be provided with a flow dividing mechanism at a refrigerant inlet, and pressure loss may occur. In contrast, in the air conditioner 1a according to the first modification, the evaporation temperature of the intermediate heat exchanger for cooling 31b can be controlled based on the detected temperature of the temperature sensor 34, and thus the risk of cracking of the intermediate heat exchanger for cooling 31b due to freezing can be suppressed.
In the first modification (fig. 6A), the case where the opening and closing of the expansion valve 33a are 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 to this. 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 for cooling 31B instead 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 section 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 if configured in this manner, the risk of cracking of the intermediate heat exchanger 31b for cooling due to freezing can be suppressed as in the case of providing the temperature sensor 34.
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 the above-described embodiment 1. Therefore, the same structures 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 in accordance with a control flow of the control section 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 control units 20, 30, 40, 50 of the respective units 2, 3, 4, 5 are linked to start the operation of the air conditioner 1 (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 air conditioner 1 is operated, and 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 operated, the operation mode selection process is not performed (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 atmosphere temperature of the outdoor unit 2. The outside air temperature sensor 2l transmits detection data (detection value of TO) TO the control section 20.
When transmitting the detection data, the control unit 20 determines a summer condition and a 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) defining a range of outside air Temperature (TO), TH is a first predetermined temperature, and TL is a second predetermined temperature having a value smaller than TH. As an example, TH is about 28 ℃ and TL is about 18 ℃, but may be arbitrarily set, and is not limited thereto. Values of the first predetermined Temperature (TH) and the second predetermined Temperature (TL) are stored in a memory device of the control unit 20, for example, and are read out as parameters in the memory when the summer condition or the winter condition is determined.
In this example, first, the control unit 20 determines the summer condition (to+.th) (S03). When the summer condition is determined, the control unit 20 compares the value of the outside air Temperature (TO) with the value of the first predetermined Temperature (TH).
When the summer condition is satisfied, the control unit 20 executes the summer operation mode selection process (S1) of the outdoor unit 2 (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 control unit 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 section 20 executes winter operation mode selection processing (S2) of the outdoor unit 2 (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, when the winter condition is not satisfied in S05, the control unit 20 executes the middle period 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 according TO the ratio of the cooling request and the heating request TO the indoor unit 5, except for summer and winter (TL < TO < TH). The details of which will be set forth later.
As described above, the control unit 20 executes 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 described.
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 a ratio of a cooling request and a heating request (hereinafter referred to as a cooling/heating request ratio) to the indoor unit 5 (S101). In the calculation, the control unit 20 acquires information (data) of a request (cooling request or heating request) of an operation mode of each indoor unit 5 from the control unit 50 of the indoor unit 5. For example, a cooling request and a heating request are set according to an operation mode selected by the user from the operation panel of the information acquisition unit 5d, and the signals are transmitted to the control unit 50.
When calculating the cooling/heating request ratio, the control unit 20 compares the cooling/heating request ratio with a predetermined threshold, and based on the result, selects the operation mode of the outdoor unit 2 as described below, and appropriately switches the operation mode. In addition to 0 (%) and 100 (%), the present embodiment uses two thresholds (A1, A2) as prescribed thresholds. 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 half of the number, and as one example, is about 51%. A2 is a second threshold value of the proportion of heating requests to the indoor unit 5. In other words, 100-A2 is also the second threshold value of the proportion of the cooling request to the indoor unit 5. A2 is an arbitrary value larger than A1 and smaller than 100%, for example, in the range from 90% to 70%, and is about 75% as an example.
The control unit 20 determines whether or not the ratio of the heat request is zero, that is, whether or not the ratio of the cooling request is 100% (S102).
When the ratio of the heating request is zero, the control unit 20 causes the outdoor unit 2 to perform a cooling operation (S103).
In contrast, when the ratio of the heating requests is not zero, the control unit 20 determines whether or not the ratio of the heating requests is smaller than the first threshold (S104).
When the ratio of the heating requests is smaller than the first threshold, the control unit 20 causes the outdoor unit 2 to perform the cooling/heating hybrid operation in which the cooling is prioritized (S105).
In contrast, when the ratio of the heating requests is equal to or greater than the first threshold, the control unit 20 determines whether or not the ratio of the heating requests is smaller than the second threshold (S106).
When the proportion 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 subjected to a cooling/heating hybrid operation in which cooling is prioritized (S105). Therefore, when the outdoor unit 2 performs the cooling-heating hybrid operation with priority of cooling, the hybrid operation is continued. That is, in this case, the operation mode of the outdoor unit 2 is maintained as the cooling-heating hybrid operation in which cooling is prioritized without switching.
In contrast, when the ratio of the heating requests is equal to or greater than the second threshold, the control unit 20 determines whether or not the ratio of the heating requests is less than 100% (S108).
When the ratio of the heating request is less than 100%, the control unit 20 causes the outdoor unit 2 to perform the cooling/heating hybrid operation in which heating is prioritized (S109). Therefore, when the outdoor unit 2 performs the cooling/heating mixture operation with the cooling priority, the control unit 20 releases the reservation of the heating request (S107), and switches from the cooling/heating mixture operation with the cooling priority to the cooling/heating mixture operation with the heating priority.
In contrast, 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 an operation mode according to the cooling/heating request ratio and appropriately switches the operation mode.
When the air conditioner 1 stops operating, 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 operation mode selection process (S2). As shown in fig. 9, the control unit 20 calculates a cooling/heating request ratio (S201). The calculation of the cooling/heating request ratio is the same as in step S101 in the summer operation mode selection process (S1).
When calculating the cooling/heating request ratio, the control unit 20 compares the cooling/heating request ratio with a predetermined threshold value, and based on the result, selects the operation mode of the outdoor unit 2 as described below, and appropriately switches the operation mode. In addition to 0 (%) and 100 (%), the present embodiment uses two thresholds (A1, A3) as prescribed thresholds. 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 of the proportion of heating requests to the indoor unit 5. In other words, 100-A3 is also the third threshold value of the proportion of the cooling request to the indoor unit 5. A3 is an arbitrary value smaller than A1 and larger than 0%, for example, in the range from 10% to 30%, and is about 25% as an example.
The control unit 20 determines whether or not the ratio of the cooling requests is zero, that is, whether or not the ratio of the heating requests 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).
In contrast, if the ratio of the heating requests is not zero, the control unit 20 determines whether or not the ratio of the cooling requests is smaller than the first threshold (S204).
When the ratio of the cooling requests is smaller than the first threshold, the control unit 20 causes the outdoor unit 2 to perform the cooling/heating hybrid operation in which heating is prioritized (S205).
In contrast, when the ratio of the cooling requests is equal to or greater than the first threshold, the control unit 20 determines whether or not the ratio of the cooling requests is smaller than the third threshold (S206).
When the proportion of the cooling request 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 made to perform the cooling/heating hybrid operation in which heating is prioritized (S205). Therefore, when the outdoor unit 2 performs the cooling-heating mixing operation with heating prioritized, the mixing operation is continued. That is, in this case, the operation mode of the outdoor unit 2 is maintained as the cooling/heating hybrid operation in which heating is prioritized without switching.
In contrast, when the ratio of the cooling requests is equal to or greater than the third threshold, the control unit 20 determines whether or not the ratio of the cooling requests 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 in which the cooling is prioritized (S209). Therefore, when the outdoor unit 2 performs the heating-priority cooling/heating hybrid operation, the control unit 20 releases the reservation of the cooling request (S207) and switches from the heating-priority cooling/heating hybrid operation to the cooling-priority cooling/heating hybrid operation.
In contrast, when the ratio 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 an operation mode according to the cooling/heating request ratio and appropriately switches the operation mode.
When the air conditioner 1 stops operating, the control unit 20 ends the season 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 a cooling/heating request ratio (S301). The calculation of the cooling/heating request ratio is the same as the step S101 in the summer operation mode selection process (S1) and the winter operation mode selection process (S2).
When calculating the cooling/heating request ratio, the control unit 20 compares the cooling/heating request ratio with a predetermined threshold value, and based on the result, selects the operation mode of the outdoor unit 2 as described below, and appropriately switches the operation mode. In addition to 0 (%) and 100 (%), the present embodiment uses the first threshold value (A1) as a 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 or not the ratio of the heat request is zero, that is, whether or not the ratio of the cooling request is 100% (S302).
When the ratio of the heating request is zero, the control unit 20 causes the outdoor unit 2 to perform a cooling operation (S303).
In contrast, if the ratio of the heating requests is not zero, the control unit 20 determines whether or not the ratio of the heating requests is smaller than the first threshold (S304).
When the ratio of the heating requests is smaller than the first threshold, the control unit 20 causes the outdoor unit 2 to perform the cooling/heating hybrid operation in which the cooling is prioritized (S305).
In contrast, when the ratio of the heating requests is equal to or greater than the first threshold, the control unit 20 determines whether or not the ratio of the heating requests is less than 100% (S306).
When the ratio of the heating request is less than 100%, the control unit 20 causes the outdoor unit 2 to perform the cooling/heating hybrid operation in which heating is prioritized (S307). Therefore, when the outdoor unit 2 performs the cooling-heating mixture operation with the cooling priority, the control portion 20 switches from the cooling-heating mixture operation with the cooling priority to the cooling-heating mixture operation with the heating priority. That is, in the intermediate 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 hybrid operation with the cooling priority is switched to the cooling/heating hybrid operation with the heating priority.
In contrast, 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 an operation mode according to the cooling/heating request ratio and appropriately switches the operation mode.
When the air conditioner 1 stops operating, the control unit 20 ends the intermediate period operation mode selection process.
In contrast, in the intermediate period operation mode selection process (S3), if the ratio of the cooling request is zero, the control section 20 switches the outdoor unit 2 to the heating operation; if the ratio of the cooling requests is zero or more and less than the first threshold, the control unit 20 switches the outdoor unit 2 to the cooling/heating hybrid operation with heating prioritized; if the ratio of the cooling request 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 with priority for cooling; if the ratio of the cooling request is 100%, the control unit 20 switches the outdoor unit 2 to the cooling operation. As described above, when the ratio of the cooling request is equal to or greater than the first threshold value and less than 100%, the control unit 20 switches the outdoor unit 2 from the heating-priority cooling-heating hybrid operation to the cooling-priority cooling-heating hybrid operation. That is, in the intermediate period operation mode selection process (S3), the cooling request to the indoor unit 5 is not held as in the winter operation mode selection process (S2), but the outdoor unit 2 is switched from the heating-priority cooling-heating hybrid operation to the cooling-priority cooling-heating hybrid operation.
Fig. 11 is a diagram showing an example in which the ratio of the cooling request and the heating request to the indoor unit 5 changes with time. In this example, the total of the proportions of the cooling requests and the heating requests for the four indoor units 5 is shown. The cooling request and the heating request are set, for example, in accordance with an operation mode or the like of the indoor unit selected by the user from the operation panel of the information acquisition unit 5 d.
In fig. 12, as shown in fig. 11, when the ratio of the cooling request and the heating request to the indoor unit 5 is changed, a change example of the operation mode of the outdoor unit 2 corresponding to the outside air temperature is shown for each season. Fig. 10 (a) is a diagram of one example of an operation mode change in the middle period (TL < TO < TH), fig. 10 (b) is a diagram of one example of an operation mode change in the summer (to+.th), and fig. 10 (c) is a diagram of one example of an operation mode change in the winter (to+.tl).
As shown in fig. 11, for example, at time t0, operation start control is performed in a state where a cooling request is made to all the indoor units 5, and then, the state is maintained to time t1. 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 is reached, the operation is performed in a state in which the indoor unit 5 for cooling and the indoor unit 5 for heating are mixed in the operation mode. During this period, as the times t2, t3, and t4 pass, the ratio of the heating requests to the indoor units 5 (the ratio of the operation mode being heating) gradually increases. After time t5, a heating request is issued to all the indoor units 5 (all the operation modes are heating). L11 shown in fig. 11 is a trace 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 the times t0, t1, t2, t3, t4, t5, and t 6. Conversely, the time series may be a time series in descending order from time t6 to time t0, or a time series in which time points other than those are randomly arranged.
In fig. 11, A1, A2, A3 are thresholds of the cooling/heating request ratio to the indoor unit, and correspond to the first, second, and third thresholds, respectively.
Fig. 12A shows a 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 a cooling state, that is, the proportion of the cooling requests to the indoor units 5 is 100%. Thus, the outdoor unit 2 is made to perform a cooling operation.
At time t1, a heating request is issued in a part of the indoor units 5, and the ratio of the heating requests to the indoor units 5 increases from 0%, and the ratio of the cooling requests decreases from 100%. At this time, the outdoor unit 2 switches from the cooling operation to the cooling-heating hybrid operation with priority of cooling.
At time t2, the ratio of heating requests to the indoor units 5 is A3%, the ratio of cooling requests is 100-A3%, but the ratio of cooling requests still exceeds 100-A1%. Therefore, the outdoor unit 2 continues the cooling-heating hybrid operation with priority of cooling.
At time t3, the ratio of heating requests to the indoor units 5 is A1%, the ratio of cooling requests is 100 to A1%, and the ratios are almost equal (as an example, the ratio of heating requests is a half of the number). At this time, the outdoor unit 2 switches from the cooling-heating hybrid operation with the priority of cooling to the cooling-heating hybrid operation with the priority of heating.
At time t4, the heating request ratio to the indoor unit 5 is increased to A2%, and the cooling request ratio is decreased to 100-A2%, but the heating request ratio is not 100%. Therefore, the outdoor unit 2 continues the cooling/heating hybrid operation in which the heating is prioritized.
At time t5, the operation mode of all the indoor units 5 is a state of heating, that is, the proportion of heating requests to the indoor units 5 becomes 100%. Therefore, the outdoor unit 2 switches from the cooling-heating hybrid operation, in which heating is prioritized, to the heating operation. Then, after the time t5, the outdoor unit 2 continues the heating operation even until the time t 6.
When the control method of the operation mode of the outdoor unit 2 at the intermediate time shown in fig. 12A is understood as a time series descending from time t6 to time t0, the outdoor unit 2 switches the operation mode as follows, contrary to the control method described above. That is, at time t5, the heating operation is switched to the cooling/heating hybrid operation with heating prioritized. Next, at time t3, the cooling/heating hybrid operation with the heating priority is switched to the cooling/heating hybrid operation with the cooling priority. Then, at time t1, the cooling-heating hybrid operation with priority of cooling is switched to the cooling operation.
As described above, by switching the operation mode of the outdoor unit 2 based on the request 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 in which a large cooling request to the indoor unit 5 is predicted, winter in which a large heating request to the indoor unit 5 is predicted, or the like, a cycle state swing 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 based on the outside air temperature in addition to the requested ratio of the operation mode of the indoor unit 5 as follows.
For example, in summer, the outdoor unit 2 is operated in the control mode of the operation mode shown in fig. 12B.
As an example, summer is when the outside air Temperature (TO) is equal TO or higher than the first predetermined Temperature (TH) (TO.gtoreq.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 at the intermediate time shown in fig. 12A. That is, the outdoor unit 2 is caused to perform the cooling operation during a period from time t0 to time t1 when the ratio of the cooling request is 100%. During a period from time t1 to time t3 when the ratio of the cooling request decreases from 100%, the outdoor unit 2 performs the cooling-heating hybrid operation with priority of cooling.
At time t3, even if the cooling request ratio further decreases to 100-A1%, which is almost equivalent to the ratio of the heating requests (A1%) (as an example, the ratio of the heating requests is half as large), the outdoor unit 2 continues the cooling-heating hybrid operation of the cooling priority. At this time, unlike the intermediate period (fig. 12A), the switching from the cooling/heating hybrid operation with the priority of cooling to the cooling/heating hybrid operation with the priority of heating is not performed.
At time t4, when the ratio of the cooling request decreases to 100-A2% and the ratio of the heating request increases to A2%, the outdoor unit 2 switches from the cooling-heating hybrid operation with the cooling priority to the cooling-heating hybrid operation with the heating priority. That is, after the switching from the cooling operation at time t1 to time t4, the cooling/heating hybrid operation with the priority of cooling is continued in the outdoor unit 2. During this period, the heating request is reserved, and the cooling-heating hybrid operation with the priority of cooling is maintained.
In this embodiment, A2 is set as the second threshold as the threshold for the ratio of heating requests to keep the heating requests and maintain the cooling-heating hybrid operation with priority of cooling, and 100-A2 is set as the second threshold as the threshold for the ratio of cooling requests.
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, in which the heating is prioritized, to the heating operation. Then, after time t5, even until time t6, the outdoor unit 2 continues the heating operation. During this period, 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 shown in fig. 12C. As an example, winter is a case where the outside air Temperature (TO) is equal TO or lower than the 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 at the intermediate time shown in fig. 12A. That is, the outdoor unit 2 is operated for heating from time t6 to time t5, at which the ratio of the heating request is 100%. During a period from time t5 when the ratio of the heating request decreases 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 ratio further decreases to 100 to A1%, which is almost equivalent to the ratio (A1%) of the cooling request (as an example, the ratio of the cooling request is half as large), the outdoor unit 2 continues the cooling/heating hybrid operation with heating prioritized. At this time, the switching from the heating-prioritized cooling-heating hybrid operation to the cooling-prioritized cooling-heating hybrid operation is not performed.
At time t2, when the ratio of the heating request decreases to A3% and the ratio of the cooling request increases to 100-A3%, the outdoor unit 2 switches from the heating-priority cooling-heating hybrid operation to the cooling-priority cooling-heating hybrid operation. That is, the cooling/heating hybrid operation, in which the heating is prioritized, is continued in the outdoor unit 2 from the time t5 after the switching of the heating operation to the time t 2. During this period, the cooling and heating hybrid operation with heating priority is maintained with the refrigeration request maintained.
In the present embodiment, as described above, 100-A3 is set as the third threshold as the threshold for the proportion of the cooling request to maintain the cooling/heating hybrid operation in which the heating is prioritized while retaining the cooling request, and A3 is set as the third threshold as the threshold for the proportion of the heating request.
Thereafter, at time t1, when the ratio of the heating requests is 0% and the ratio of the cooling requests is 100%, the outdoor unit 2 switches from the cooling-heating hybrid operation, in which cooling is prioritized, to the cooling operation. Then, after the time t1, the outdoor unit 2 continues the heating operation even until the time t 0. The manner of controlling the operation mode of the outdoor unit 2 during this period is the same as the intermediate period shown in fig. 12A.
By switching the operation mode of the outdoor unit 2 based on the outside air temperature in addition to the request ratio of the operation mode of the indoor unit 5, the timing of switching from the cooling/heating hybrid operation with the cooling priority to the cooling/heating hybrid operation with the heating priority can be shifted (delayed). Thus, for example, in summer (to+.th), even when 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 predicted TO request more cooling priority can be maintained. On the other hand, in winter (to+.tl), even when 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 request more heating priority 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 ability of predicting the operation mode in which a large number of requests are required and the occurrence of hunting in the circulation state. Even in the operation mode of the indoor unit 5 predicted to request less, for example, the heating mode in summer and the cooling mode in winter, when a certain request ratio (the second threshold or the third threshold) is exceeded, the operation mode of the outdoor unit 2 is switched. Therefore, the reservation of the request for the operation mode predicted to be less requested 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, even in summer, the operation mode of the outdoor unit 2 can be appropriately switched to the heating-prioritized cooling-heating hybrid operation, and even in winter, the operation mode of the outdoor unit 2 can be appropriately switched to the cooling-prioritized cooling-heating hybrid operation. That is, the capability of providing 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 ratio can be more effectively reduced.
In the above embodiment, the second threshold value and the third threshold value are set in addition to the first threshold value as the threshold value defining the range of the outside air temperature, but the threshold value added to the first threshold value may be further increased. Thereby, the operation mode of the outdoor unit 2 can be further switched in multiple stages, and the capability of the operation mode actually requested by the user can be provided more finely.
(embodiment 2)
Next, embodiment 2 will be described. The configuration of the air conditioner according to embodiment 2 is the same as that of the air conditioner 1 according to embodiment 1 shown in fig. 1 and 2.
Hereinafter, switching control of the operation modes (first mode, second mode) at the time of cooling operation and at the time of heating operation in the air conditioner 1 of the present embodiment will be described.
Fig. 13 shows a relationship between the operation modes (first mode, second mode) at the time of cooling operation and at the time of heating operation and the target temperature of the heating agent. 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 time of the cooling operation is set higher than the target temperature of the first mode.
When the target temperature in the first mode (normal operation mode) is the target temperature TB1 during the heating operation of the air conditioner 1, 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 lower than the target temperature of the first mode. Here, for example, target temperatures TA1, TA2, TB1, TB2 of the heating agent may be set from the control panel 100.
Next, the switching process of the operation mode performed by the control unit will be described. A flowchart as one example of the switching process of this operation mode is shown in fig. 14. In the present embodiment, a case will be described in which the control unit 30 of the heat exchange unit 3 performs main control, and the control unit 20 performs rotation control of the compressor 2 a.
The control unit 30 determines whether the operation of the air conditioner 1 is a cooling operation or a heating operation based on an instruction from the control panel 100, for example (ST 101). In step ST101, when it is determined 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. When the first mode (normal operation mode) is determined, the control unit 30 sets TA1 as the target temperature of the heating agent (ST 103). That is, the current operating state is continued. If it is determined that the second mode (energy saving operation mode), the control unit 30 sets TA2 (> TA 1) as the target temperature of the heating agent (ST 104). Thereby, the target temperature of the heating agent during the cooling operation is changed.
On the other hand, in step ST101, when it is determined that the heating operation is performed, the control unit 30 determines the mode (ST 105). The mode determination based on the instruction from the control panel 100 is the same as the case of the cooling operation. When it is determined that the first mode (normal operation mode) is the first mode, the control unit 30 sets TB1 as the target temperature of the heating agent (ST 106). That is, the current operating state is continued. When the second mode (energy saving operation mode) is determined, the control unit 30 sets TB2 (< TB 1) as the target temperature of the heating agent (ST 107). Thereby, the target temperature of the heating agent during the heating operation is changed. 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 obtained from the heating agent becomes the target temperature set for the heating agent.
Next, the operational effects of the air conditioner 1 will be described.
When each indoor unit 5 performs a cooling operation, the rotation speed of the compressor 2a of the outdoor unit 2 is controlled according to the target temperature of the heating agent set for the intermediate heat exchanger 31b for cooling. 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 intermediate heat exchanger for cooling 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 intermediate heat exchanger for cooling 31b, that is, the target temperature of the heating agent is set to 12 ℃. As described above, in the second mode, the target temperature of the heating agent is set higher than in the first mode, so that the rotation speed of the compressor 2a of the outdoor unit 2 can be suppressed at the time of setting the second mode, and 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 according to the target temperature of the heating agent set for the heating intermediate heat exchanger 32 b. Therefore, the higher the target temperature of the heating agent, the higher the rotation speed of the compressor 2 a. For example, in the first mode (normal operation mode), the outlet set temperature of the intermediate heat exchanger for heating 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 intermediate heat exchanger for heating 32b, that is, the target temperature of the heating agent is set to 40 ℃. In the second mode, the target temperature of the heating agent is set lower than in the first mode, so that the rotation speed of the compressor 2a of the outdoor unit 2 can be suppressed at the time of setting the second mode, and 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, when the power peaks, the administrator 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, whereby the power consumption at the time of the peak can be suppressed. That is, the air conditioner 1 can save energy.
In the present embodiment, the case where the operation mode of the air conditioner 1 is changed by the manager 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 be able to change the operation mode of the air conditioner 1 from the first mode to the second mode according to the operation condition 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 operation condition of each indoor unit 5. The control unit 30 communicates with the control unit 40 of the valve unit 4 to acquire the operation state of each indoor unit 5, and when the operation state of all the indoor units 5 is acquired to operate at the minimum capacity, the control unit 30 changes the operation mode of the air conditioner 1 from the first mode (normal operation mode) to the second mode (energy saving mode). Even in this way, as in the above embodiment, the rotation speed of the compressor 2a of the outdoor unit 2 can be suppressed, and the energy consumption of the air conditioner 1 can be reduced. In addition, even if no instruction is given from the control panel 100, the air conditioner 1 can automatically save energy consumption.
In the present embodiment, the case where the pumps 5a are provided in the respective indoor units 5 has been described, but the positions of the pumps may be provided in the vicinity of the respective indoor units 5 instead of in 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 agent for cooling and a pump Pb for adjusting the flow rate of the heating agent for heating may be provided between the heat exchange unit 3 and the valve unit 4, respectively. Fig. 15 shows an air conditioner 1c according to a third modification. The basic structure of the air conditioner 1c is the same as that of the air conditioner 1 of embodiment 1. Therefore, the same components 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
Next, embodiment 3 will be described. The basic structure 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 components 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 that the arrangement of the intermediate heat exchanger for cooling 31b and the intermediate heat exchanger for heating 32b is performed. Therefore, the arrangement of the intermediate heat exchanger for cooling 31b and the intermediate heat exchanger for heating 32b will be described in detail.
In the present embodiment, a compact plate heat exchanger is used as the intermediate heat exchanger for cooling 31b and the intermediate heat exchanger for heating 32b. The plate heat exchanger is generally designed such that the long side direction is a vertical direction, 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 flow path cross-sectional area 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 in 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 the back of the ceiling. Therefore, the height direction (vertical direction) of the housing is preferably designed to be as small as possible. Accordingly, as shown in fig. 16 and 17, the intermediate heat exchanger for cooling 31b and the intermediate heat exchanger for heating 32b are provided, respectively. In fig. 16 and 17, the lower side is shown as the installation 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 31b for cooling is provided so that the refrigerant flows in a vertical direction from below to above with respect to the installation surface G. That is, the refrigerant is provided on the installation surface G such that the inlet E11 of the refrigerant is located below and the outlet E12 of the refrigerant is located above, and the refrigerant flows in from the inlet E11 and then flows out from the outlet E12 in a gas phase (gas) state as indicated by an arrow R1 in the drawing. Since the two-phase refrigerant (gas phase and liquid phase) flows into the intermediate heat exchanger 31b for cooling, if the refrigerant is provided in the horizontal direction with respect to the installation surface G (as in the intermediate heat exchanger 32b for heating in fig. 17), the refrigerant liquid is biased to the lower side, and therefore the plate in the intermediate heat exchanger 31b for cooling cannot be used effectively, and the performance of the heat exchanger is greatly lowered, and there is a possibility that problems such as freezing due to a lowering of the evaporation temperature may occur. Therefore, as shown in fig. 16, an intermediate heat exchanger 31b for cooling 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 such that the refrigerant flows in the horizontal direction with respect to the installation surface G. That is, as shown by the illustrated 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, since the refrigerant flows in a gas phase (gas) state and flows out in a refrigerant liquid (condensate) state, 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 degradation of the heat exchanger can be suppressed as compared with the intermediate heat exchanger for cooling 31b. Therefore, as shown in fig. 17, the intermediate heat exchanger for heating 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 the intermediate heat exchanger 32b for heating may be one, the cost of the intermediate heat exchanger can be reduced and the manufacturing cost due to the increase in the number of parts and the number of welded parts can be reduced in addition to the reduction in the performance of the air conditioner 1.
In the present embodiment, the case where the number of the intermediate heat exchangers 31b for cooling in the heat exchange unit 3 is 3 has been described, but the number of the intermediate heat exchangers 31b for cooling 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 minimizing the increase in the number of welded parts and the number of components depending on the environments such as the installation area of the installed location and the height of the installed location.
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 novel embodiments may be implemented in various other ways, and various omissions, substitutions, and changes may be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the invention described in the scope of claims and their equivalents.
Description of the reference numerals
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 switching valve, 5 … indoor unit, 5a … circulation pump, 5b … indoor side heat exchanger, 5d … information acquisition part, 6 … refrigerant piping, 6a … liquid piping, 6b … intake gas piping, 6c … exhaust gas piping, 7, 8 … heating agent piping, 7a … cooling agent supply pipe, 7b … heating agent return pipe, 8b … heating agent return pipe, 9 … distribution pipe, 9a … inlet pipe, 9b … return pipe, 20, 30, 40, 50 … control part, 21, 31, 41, 51 … housing, 31b … cooling intermediate heat exchanger, 32b … heat exchanger, 31d, 31E 37, 31E, 35E 37 pressure sensor, 21E, and 21E 37 inlet and outlet valve … E, and pressure sensor … inlet and outlet.

Claims (6)

1. An air conditioner, 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 heat-exchanging 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 heating agent cooled by the intermediate heat exchanger and the heating agent heated to flow into the indoor side heat exchanger; and
a control unit having a control section for controlling the respective units,
the outdoor unit, the heat exchange unit, the indoor unit, and the valve unit are divided and formed with housings,
the outdoor unit and the heat exchange unit are connected by a liquid pipe that conveys condensate condensed by the outdoor side heat exchanger to the heat exchange unit or conveys condensate condensed by the intermediate heat exchanger to the outdoor unit, a suction gas pipe that conveys refrigerant evaporated by the intermediate heat exchanger to the outdoor unit, and a discharge gas pipe that conveys 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,
The exhaust gas is condensed by the outdoor heat exchanger, and the condensed condensate is flowed into the intermediate heat exchanger through the second expansion valve to perform a cooling operation,
a cooling/heating mixing operation in which a part of the exhaust gas is introduced into one of the plurality of intermediate heat exchangers and condensed, the remaining part of the exhaust gas is condensed by the outdoor heat exchanger, the condensed condensate is mixed with the refrigerant condensed by the intermediate heat exchanger through the liquid pipe, the mixed condensate is introduced into the other intermediate heat exchanger through the second expansion valve and evaporated, and the cooling priority is given to the cooling/heating mixing operation,
the exhaust gas is flowed into one of the plurality of intermediate heat exchangers and condensed, a part of the exhaust gas is flowed into the outdoor side heat exchanger through the liquid pipe and evaporated, and the remaining part of the condensed liquid is flowed into the other intermediate heat exchanger through the second expansion valve and evaporated, whereby a heating-prioritized cooling/heating mixing operation is performed,
The pipe diameters of the pipes connecting the outdoor unit and the heat exchange unit are as follows: the suction gas pipe > the discharge gas pipe > the liquid pipe,
at least one of the intermediate heat exchangers is a cooling intermediate heat exchanger for cooling the refrigerant during a cooling operation, the remaining intermediate heat exchangers are heating intermediate heat exchangers for heating the refrigerant during a 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 intermediate heat exchanger for heating and the intermediate heat exchanger for cooling,
a third expansion valve is arranged in the heat exchange unit,
the third expansion valve is provided between the intake gas pipe and the intermediate heat exchanger for cooling.
2. The air conditioner according to claim 1, wherein,
the third expansion valve operates based on an inlet temperature of the intermediate cooling heat exchanger or an evaporation gas saturation temperature obtained by converting an outlet pressure of the intermediate cooling heat exchanger into a saturation temperature.
3. An air conditioner, 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 heat-exchanging 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 heating agent cooled by the intermediate heat exchanger and the heating agent heated to flow into the indoor side heat exchanger; and
a control unit having a control section for controlling the respective units,
the outdoor unit, the heat exchange unit, the indoor unit, and the valve unit are divided and formed with housings,
the outdoor unit and the heat exchange unit are connected by a liquid pipe that conveys condensate condensed by the outdoor side heat exchanger to the heat exchange unit or conveys condensate condensed by the intermediate heat exchanger to the outdoor unit, a suction gas pipe that conveys refrigerant evaporated by the intermediate heat exchanger to the outdoor unit, and a discharge gas pipe that conveys 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,
the exhaust gas is condensed by the outdoor heat exchanger, and the condensed condensate is flowed into the intermediate heat exchanger through the second expansion valve to perform a cooling operation,
a cooling/heating mixing operation in which a part of the exhaust gas is introduced into one of the plurality of intermediate heat exchangers and condensed, the remaining part of the exhaust gas is condensed by the outdoor heat exchanger, the condensed condensate is mixed with the refrigerant condensed by the intermediate heat exchanger through the liquid pipe, the mixed condensate is introduced into the other intermediate heat exchanger through the second expansion valve and evaporated, and the cooling priority is given to the cooling/heating mixing operation,
the exhaust gas is flowed into one of the plurality of intermediate heat exchangers and condensed, a part of the exhaust gas is flowed into the outdoor side heat exchanger through the liquid pipe and evaporated, and the remaining part of the condensed liquid is flowed into the other intermediate heat exchanger through the second expansion valve and evaporated, whereby a heating-prioritized cooling/heating mixing operation is performed,
The intermediate heat exchanger is a plate heat exchanger formed by stacking plates,
the plurality of plate heat exchangers includes a plurality of intermediate heat exchangers for cooling the heating agent, and a smaller number of intermediate heat exchangers for heating the refrigerant than the plurality of intermediate heat exchangers for cooling,
the intermediate heat exchanger for cooling is provided so that the refrigerant flows in a vertical direction with respect to the installation surface,
the intermediate heat exchanger for heating is provided such that the refrigerant flows in a horizontal direction with respect to the installation surface.
4. An air conditioner, 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 heat-exchanging 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 heating agent cooled by the intermediate heat exchanger and the heating agent heated to flow into the indoor side heat exchanger; and
A control unit having a control section for controlling the respective units,
the outdoor unit, the heat exchange unit, the indoor unit, and the valve unit are divided and formed with housings,
the outdoor unit and the heat exchange unit are connected by a liquid pipe that conveys condensate condensed by the outdoor side heat exchanger to the heat exchange unit or conveys condensate condensed by the intermediate heat exchanger to the outdoor unit, a suction gas pipe that conveys refrigerant evaporated by the intermediate heat exchanger to the outdoor unit, and a discharge gas pipe that conveys 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,
the exhaust gas is condensed by the outdoor heat exchanger, and the condensed condensate is flowed into the intermediate heat exchanger through the second expansion valve to perform a cooling operation,
a cooling/heating mixing operation in which a part of the exhaust gas is introduced into one of the plurality of intermediate heat exchangers and condensed, the remaining part of the exhaust gas is condensed by the outdoor heat exchanger, the condensed condensate is mixed with the refrigerant condensed by the intermediate heat exchanger through the liquid pipe, the mixed condensate is introduced into the other intermediate heat exchanger through the second expansion valve and evaporated, and the cooling priority is given to the cooling/heating mixing operation,
The exhaust gas is flowed into one of the plurality of intermediate heat exchangers and condensed, a part of the exhaust gas is flowed into the outdoor side heat exchanger through the liquid pipe and evaporated, and the remaining part of the condensed liquid is flowed into the other intermediate heat exchanger through the second expansion valve and evaporated, whereby a heating-prioritized cooling/heating mixing operation is performed,
the outdoor unit has an outside air temperature sensor for detecting an outside air temperature,
the control section selects any one of the heating operation, the cooling-heating hybrid operation with the priority of cooling, and the cooling-heating hybrid operation with the priority of heating to operate the outdoor unit 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,
the control unit sets a first predetermined temperature defining a range of the outside air temperature TO TH, sets a second predetermined temperature TO TL when the outside air temperature detected by the outside air temperature sensor is TO,
Then, in the case TL < TO < TH, when the outdoor unit performs the cooling-heating hybrid operation with the cooling priority, if the ratio of the heating request TO the indoor unit is a first threshold or more, the outdoor unit is switched from the cooling-heating hybrid operation with the cooling priority TO the cooling-heating hybrid operation with the heating priority, when the outdoor unit performs the cooling-heating hybrid operation with the heating priority, if the ratio of the cooling request TO the indoor unit is a first threshold or more, the outdoor unit is switched from the cooling-heating hybrid operation with the heating priority TO the cooling-heating hybrid operation with the cooling priority,
if TO is larger than or equal TO TH, if the outdoor unit performs the cooling/heating hybrid operation with the cooling priority, the outdoor unit is continuously made TO perform the cooling/heating hybrid operation with the cooling priority even if the ratio of the heating requests TO the indoor unit is equal TO or larger than the first threshold value,
if TO is equal TO or less than TL, if the outdoor unit performs the heating-prioritized cooling/heating hybrid operation, the outdoor unit is continuously caused TO perform the heating-prioritized cooling/heating hybrid operation even if the ratio of the cooling requests TO the indoor unit is equal TO or greater than the first threshold.
5. The air conditioner according to claim 4, wherein,
the control unit switches the outdoor unit from the cooling/heating hybrid operation with the cooling priority TO the cooling/heating hybrid operation with the heating priority if the ratio of heating requests TO the indoor unit is equal TO or greater than a second threshold value that is greater than the first threshold value when TO is equal TO or greater than TH,
and if the ratio of the cooling request TO the indoor unit is equal TO or greater than a third threshold value greater than the first threshold value, switching the outdoor unit from the heating-priority cooling-heating hybrid operation TO the cooling-priority cooling-heating hybrid operation.
6. An air conditioner, 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 heat-exchanging 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 heating agent cooled by the intermediate heat exchanger and the heating agent heated to flow into the indoor side heat exchanger; and
a control unit having a control section for controlling the respective units,
the outdoor unit, the heat exchange unit, the indoor unit, and the valve unit are divided and formed with housings,
the outdoor unit and the heat exchange unit are connected by a liquid pipe that conveys condensate condensed by the outdoor side heat exchanger to the heat exchange unit or conveys condensate condensed by the intermediate heat exchanger to the outdoor unit, a suction gas pipe that conveys refrigerant evaporated by the intermediate heat exchanger to the outdoor unit, and a discharge gas pipe that conveys 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,
the exhaust gas is condensed by the outdoor heat exchanger, and the condensed condensate is flowed into the intermediate heat exchanger through the second expansion valve to perform a cooling operation,
A cooling/heating mixing operation in which a part of the exhaust gas is introduced into one of the plurality of intermediate heat exchangers and condensed, the remaining part of the exhaust gas is condensed by the outdoor heat exchanger, the condensed condensate is mixed with the refrigerant condensed by the intermediate heat exchanger through the liquid pipe, the mixed condensate is introduced into the other intermediate heat exchanger through the second expansion valve and evaporated, and the cooling priority is given to the cooling/heating mixing operation,
the exhaust gas is flowed into one of the plurality of intermediate heat exchangers and condensed, a part of the exhaust gas is flowed into the outdoor side heat exchanger through the liquid pipe and evaporated, and the remaining part of the condensed liquid is flowed into the other intermediate heat exchanger through the second expansion valve and evaporated, whereby a heating-prioritized cooling/heating mixing operation is performed,
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 of the operation modes at the time of cooling operation and at the time of heating operation, and acquires the temperature of the heating agent detected by the temperature sensor, controls the 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 which operates in a power saving manner than the first mode,
the target temperature of the second mode at the time of the cooling operation is set higher than the target temperature of the first mode, the target temperature of the second mode at the time of the heating operation is set lower than the target temperature of the first mode,
the valve unit includes a communication unit for communicating with a plurality of the indoor units connected thereto, respectively,
the control unit acquires the operation 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 operation states of the plurality of indoor units.
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Families Citing this family (2)

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Publication number Priority date Publication date Assignee Title
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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
CN102395841B (en) * 2009-04-17 2015-07-22 三菱电机株式会社 Heating medium converter and air-conditioning device
WO2010131378A1 (en) * 2009-05-12 2010-11-18 三菱電機株式会社 Air conditioner
WO2013102953A1 (en) * 2012-01-05 2013-07-11 三菱電機株式会社 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

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