US20190383509A1 - Refrigeration cycle device and refrigeration cycle system - Google Patents

Refrigeration cycle device and refrigeration cycle system Download PDF

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Publication number
US20190383509A1
US20190383509A1 US16/470,680 US201716470680A US2019383509A1 US 20190383509 A1 US20190383509 A1 US 20190383509A1 US 201716470680 A US201716470680 A US 201716470680A US 2019383509 A1 US2019383509 A1 US 2019383509A1
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United States
Prior art keywords
refrigerant
air
controller
leakage
sending fan
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US16/470,680
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English (en)
Inventor
Masahiko Takagi
Yasuhiro Suzuki
Kenyu Tanaka
Kazuki Watanabe
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Publication date
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Assigned to MITSUBISHI ELECTRIC CORPORATION reassignment MITSUBISHI ELECTRIC CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TAKAGI, MASAHIKO, TANAKA, KENYU, WATANABE, KAZUKI, SUZUKI, YASUHIRO
Publication of US20190383509A1 publication Critical patent/US20190383509A1/en
Abandoned legal-status Critical Current

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    • 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
    • F24F11/32—Responding to malfunctions or emergencies
    • F24F11/36—Responding to malfunctions or emergencies to leakage of heat-exchange fluid
    • 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
    • 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
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Definitions

  • the present invention relates to a refrigeration cycle device and a refrigeration cycle system that detect the leakage of refrigerant with a refrigerant detector.
  • Patent Literature 1 describes an air conditioning device.
  • the air conditioning device is equipped with a gas sensor that is provided on the outer surface of an indoor unit and that detects refrigerant, and a controller that causes an indoor air-sending fan to rotate when the gas sensor detects refrigerant.
  • the gas sensor in the case where refrigerant leaks into a room from an extension pipe connected to the indoor unit, or in the case where refrigerant leaking internally in the indoor unit passes through a gap in the housing of the indoor unit and flows to the outside of the indoor unit, the leaking refrigerant can be detected by the gas sensor.
  • the indoor air-sending fan by causing the indoor air-sending fan to rotate when the leakage of refrigerant is detected, as air inside the room is sucked into an air inlet provided in the housing of the indoor unit and air is blown out into the room from an air outlet, the leaking refrigerant can be diffused.
  • Patent Literature 1 Japanese Patent No. 4599699
  • a gas sensor such as a semiconductor gas sensor that is a refrigerant detector has a feature of reacting to hydrogen (H), carbon (C), or other substances in the atmosphere.
  • a gas sensor having such a feature reacts to the nearby existence of substances containing hydrogen (H) and carbon (C), such as propane (C 3 H 8 ), butane (C 4 H 10 ), and ethanol (C 2 H 6 O).
  • propane (C 3 H 8 ) or butane (C 4 H 10 ) is contained in sprays commercially available.
  • ethanol (C 2 H 6 O) is used widely as a disinfectant alcohol.
  • an air conditioning device when sprays including propane or butane are used or when ethanol is used as a disinfectant alcohol, there is a possibility that the gas sensor incorrectly detects leakage even though refrigerant is not present.
  • the air conditioning device often is configured to, in the case where refrigerant is incorrectly detected, activate an abnormality alarm and stop running. For this reason, there are issues such as that a user is unable to run the air conditioning device until the air conditioning device is repaired by a service member, even though refrigerant is not leaking.
  • the present invention has been devised to address issues like the above, and an objective of the present invention is to provide a refrigeration cycle device and a refrigeration cycle system capable of inhibiting a change in the detection characteristics of a refrigerant detector.
  • a refrigeration cycle device includes a refrigerant circuit configured to cause refrigerant to circulate, a heat exchanger unit that houses a heat exchanger of the refrigerant circuit, and a controller configured to control the heat exchanger unit.
  • the heat exchanger unit is provided with an air-sending fan and a refrigerant detector.
  • the controller is configured to cause the air-sending fan to run, and is configured to disregard a detection signal from the refrigerant detector when a rotational speed of the air-sending fan is equal to or greater than a first threshold value, even if the controller detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector.
  • a refrigeration cycle system includes a refrigeration cycle device including a refrigerant circuit configured to cause refrigerant to circulate and a controller configured to control the refrigerant circuit, an air-sending fan controlled by the controller, and a refrigerant detector configured to output a detection signal to the controller.
  • the controller is configured to cause the air-sending fan to run, and is configured to disregard the detection signal from the refrigerant detector when a rotational speed of the air-sending fan is equal to or greater than a first threshold value, even if the controller detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector.
  • the present invention as a configuration that disregards the detection signal from the refrigerant detector is provided, it is possible to prevent incorrect detection by the refrigerant detector in conditions where the air-sending fan is rotating and a flammable zone cannot be imposed.
  • FIG. 1 is a refrigerant circuit diagram illustrating a schematic configuration of an air conditioning device according to Embodiment 1 of the present invention.
  • FIG. 2 is a front view schematically illustrating an internal structure of an indoor unit 1 of the air conditioning device according to Embodiment 1 of the present invention.
  • FIG. 3 is a side view schematically illustrating the internal structure of the indoor unit 1 of the air conditioning device according to Embodiment 1 of the present invention.
  • FIG. 4 is a flowchart illustrating one example of a refrigerant leakage detection process executed by a controller 30 of the air conditioning device according to Embodiment 1 of the present invention.
  • FIG. 5 is a state transition diagram illustrating one example of state transitions of the air conditioning device according to Embodiment 1 of the present invention.
  • FIG. 6 is a diagram illustrating the relationship, in an air conditioning device according to Embodiment 2 of the present invention, between the rotational speed of an indoor air-sending fan 7 f and states of the air conditioning device.
  • FIG. 7 is a diagram schematically illustrating a configuration of an outdoor unit 2 of an air conditioning device according to Embodiment 3 of the present invention.
  • FIG. 8 is a diagram illustrating a schematic overall configuration of a refrigeration cycle system according to Embodiment 4 of the present invention.
  • FIG. 9 is a block diagram illustrating a configuration of a controller 30 of the refrigeration cycle system according to Embodiment 4 of the present invention.
  • FIG. 1 is a refrigerant circuit diagram illustrating a schematic configuration of the air conditioning device according to Embodiment 1. Note that in the following diagrams, including FIG. 1 , the relative dimensions, shapes, and other features of each of the structural elements may differ from those of the actual elements in some cases.
  • the air conditioning device includes a refrigerant circuit 40 that causes refrigerant to circulate.
  • the refrigerant circuit 40 has a configuration in which a compressor 3 , a refrigerant channel switching device 4 , a heat source side heat exchanger 5 (for example, an outdoor heat exchanger), a pressure-reducing device 6 , and a load side heat exchanger 7 (for example, an indoor heat exchanger) are sequentially connected in a ring via refrigerant pipes.
  • the air conditioning device includes an outdoor unit 2 installed outdoors for example as a heat source unit.
  • the air conditioning device includes an indoor unit 1 (one example of a heat exchanger unit) installed indoors for example as a load unit.
  • the indoor unit 1 and the outdoor unit 2 are connected via extension pipes 10 a and 10 b that are part of the refrigerant pipes.
  • a mildly flammable refrigerant such as HFO-1234yf and HFO-1234ze, or a highly flammable refrigerant such as R290 and R1270 is used.
  • These refrigerants may be used as a single refrigerant, or two or more types may be mixed and used as a refrigerant mixture.
  • refrigerants that have at least a mild level of flammability for example, 2L or higher in the classification of ASHRAE 34
  • refrigerant that circulates through the refrigerant circuit 40 it is also possible to use a non-flammable refrigerant such as R22 and R410A designated as non-flammable (1 in the classification of ASHRAE 34). These refrigerants are denser than air under atmospheric pressure, for example.
  • the compressor 3 is a fluid machine that compresses suctioned low-pressure refrigerant, and discharges high-pressure refrigerant.
  • the refrigerant channel switching device 4 switches the directions of the flow of refrigerant inside the refrigerant circuit 40 between cooling operation and heating operation.
  • a four-way valve is used, for example.
  • the heat source side heat exchanger 5 is a heat exchanger that serves as a radiator (for example, a condenser) during cooling operation, and as an evaporator during heating operation. In the heat source side heat exchanger 5 , heat is exchanged between internally circulating refrigerant and outdoor air sent by an outdoor air-sending fan 5 f described later.
  • the pressure-reducing device 6 reduces the pressure of high-pressure refrigerant to produce low-pressure refrigerant.
  • an electronic expansion valve or another device with an adjustable opening degree is used, for example.
  • the load side heat exchanger 7 is a heat exchanger that serves as an evaporator during cooling operation and as a radiator (for example, a condenser) during heating operation. In the load side heat exchanger 7 , heat is exchanged between internally circulating refrigerant and air sent by an indoor air-sending fan 7 f described later.
  • cooling operation refers to operation that supplies low-temperature and low-pressure refrigerant to the load side heat exchanger 7
  • heating operation refers to operation that supplies high-temperature and high-pressure refrigerant to the load side heat exchanger 7 .
  • the outdoor unit 2 houses the compressor 3 , the refrigerant channel switching device 4 , the heat source side heat exchanger 5 , and the pressure-reducing device 6 . Also, the outdoor unit 2 houses the outdoor air-sending fan 5 f that supplies outdoor air to the heat source side heat exchanger 5 .
  • the outdoor air-sending fan 5 f is installed to face the heat source side heat exchanger 5 . By causing the outdoor air-sending fan 5 f to rotate, airflow that passes through the heat source side heat exchanger 5 is generated.
  • a propeller fan is used, for example.
  • the outdoor air-sending fan 5 f is disposed downstream of the heat source side heat exchanger 5 for example in the airflow generated by the outdoor air-sending fan 5 f.
  • a refrigerant pipe that serves as a gas pipe during cooling operation and that joins an extension pipe connecting valve 13 a to the refrigerant channel switching device 4 a suction pipe 11 connected to the suction port of the compressor 3 , a discharge pipe 12 connected to the discharge port of the compressor 3 , a refrigerant pipe that joins the refrigerant channel switching device 4 to the heat source side heat exchanger 5 , a refrigerant pipe that joins the heat source side heat exchanger 5 to the pressure-reducing device 6 , and a refrigerant pipe that serves as a liquid pipe during cooling operation and that joins an extension pipe connecting valve 13 b to the pressure-reducing device 6 are disposed as the refrigerant pipes.
  • the extension pipe connecting valve 13 a is a two-way valve capable of switching between being open and closed and having one end with a flare fitting attached. Also, the extension pipe connecting valve 13 b is configured as a three-way pipe capable of switching between being open and closed. One end of the extension pipe connecting valve 13 b is attached with a service port 14 a used for vacuuming in preparation for filling the refrigerant circuit 40 with refrigerant, while the other end is attached with a flare fitting.
  • a service port 14 b having a flare fitting for low-pressure part is connected to the suction pipe 11
  • a service port 14 c having a flare fitting for the high-pressure part is connected to the discharge pipe 12 .
  • the service ports 14 b and 14 c are used to connect a pressure gauge and measure the running pressure during a test run for installation and repair of the air conditioning device.
  • the indoor unit 1 houses the load side heat exchanger 7 . Also, in the indoor unit 1 , the indoor air-sending fan 7 f that supplies air to the load side heat exchanger 7 is installed. By causing the indoor air-sending fan 7 f to rotate, airflow that passes through the load side heat exchanger 7 is generated.
  • a centrifugal fan such as a sirocco fan and turbo fan
  • a cross-flow fan such as a sirocco fan and turbo fan
  • a cross-flow fan such as a sirocco fan and turbo fan
  • a diagonal flow fan for example, a propeller fan
  • the indoor air-sending fan 7 f of the present example is installed upstream of the load side heat exchanger 7 in the airflow generated by the indoor air-sending fan 7 f , but may also be installed downstream of the load side heat exchanger 7 .
  • an indoor pipe 9 a that is a gas pipe among the refrigerant pipes of the indoor unit 1
  • a fitting section 15 a for example, a flare fitting
  • an indoor pipe 9 b that is a liquid pipe among the refrigerant pipes of the indoor unit 1
  • a fitting section 15 b for example, a flare fitting
  • the indoor unit 1 is provided with a suction air temperature sensor 91 that measures the temperature of indoor air sucked in from the indoor space, a heat exchanger inlet temperature sensor 92 that measures the refrigerant temperature at the inlet during cooling operation (the outlet during heating operation) of the load side heat exchanger 7 , a heat exchanger temperature sensor 93 that measures the two-phase refrigerant temperature (evaporating temperature or condensing temperature) of the load side heat exchanger 7 , or other sensors. Furthermore, the indoor unit 1 is provided with a refrigerant detector 99 (for example, a semiconductor gas sensor) described later. These sensors are configured to output detection signals to a controller 30 that controls the indoor unit 1 or the air conditioning device as a whole.
  • a refrigerant detector 99 for example, a semiconductor gas sensor
  • the controller 30 includes a microcomputer (hereinafter designated as “micro” in some cases) provided with a CPU, ROM, RAM, input-output ports, and another device.
  • the controller 30 is able to communicate data bidirectionally with an operating unit not illustrated.
  • the operating unit receives an operation performed by a user, and outputs an operating signal based on the operation to the controller 30 .
  • the controller 30 of the present example controls the action of the indoor unit 1 or the air conditioning device as a whole, including the action of the indoor air-sending fan 7 f , on the basis of operating signals from the operating unit, detection signals from the sensors, or other signals.
  • the controller 30 is able to switch between powering and not powering the refrigerant detector 99 .
  • the controller 30 may be provided inside the housing of the indoor unit 1 or inside the housing of the outdoor unit 2 . Also, the controller 30 may be configured with an outdoor unit controller provided in the outdoor unit 2 and an indoor unit controller provided in the indoor unit 1 and capable of data communication with the outdoor unit controller.
  • the action of the refrigerant circuit 40 of the air conditioning device will be described.
  • the action during cooling operation will be described.
  • the solid arrows illustrate the direction of the flow of refrigerant during cooling operation.
  • the refrigerant channel is switched by the refrigerant channel switching device 4 as illustrated by the solid lines, and a refrigerant circuit 40 is configured in such a manner that low-temperature and low-pressure refrigerant flows to the load side heat exchanger 7 .
  • High-temperature and high-pressure gas refrigerant discharged from the compressor 3 first flows into the heat source side heat exchanger 5 via the refrigerant channel switching device 4 .
  • the heat source side heat exchanger 5 serves as a condenser.
  • heat is exchanged between internally circulating refrigerant and outdoor air sent by the outdoor air-sending fan 5 f , and the heat of condensation of the refrigerant is transferred to the outdoor air. With this action, the refrigerant flowing into the heat source side heat exchanger 5 condenses to become high-pressure liquid refrigerant.
  • the high-pressure liquid refrigerant flows into the pressure-reducing device 6 , and is decompressed to become low-pressure two-phase refrigerant.
  • the low-pressure two-phase refrigerant flows into the load side heat exchanger 7 of the indoor unit 1 via the extension pipe 10 b .
  • the load side heat exchanger 7 serves as an evaporator.
  • heat is exchanged between internally circulating refrigerant and air (for example, indoor air) sent by the indoor air-sending fan 7 f , and the heat of evaporation of the refrigerant is received from the sent air.
  • the refrigerant flowing into the load side heat exchanger 7 evaporates to become low-pressure gas refrigerant or two-phase refrigerant.
  • the air sent by the indoor air-sending fan 7 f is cooled by the heat-absorbing action of the refrigerant.
  • the low-pressure gas refrigerant or two-phase refrigerant evaporated in the load side heat exchanger 7 passes through the extension pipe 10 a and the refrigerant channel switching device 4 , and is suctioned into the compressor 3 .
  • the refrigerant suctioned into the compressor 3 is compressed to become high-temperature and high-pressure gas refrigerant. In cooling operation, the above cycle is repeated.
  • the dashed arrows illustrate the direction of the flow of refrigerant during heating operation.
  • the refrigerant channel is switched by the refrigerant channel switching device 4 as illustrated by the dashed lines, and a refrigerant circuit 40 is configured in such a manner that high-temperature and high-pressure refrigerant flows to the load side heat exchanger 7 .
  • refrigerant flows in the opposite direction than that of cooling operation, and the load side heat exchanger 7 serves as a condenser.
  • FIG. 2 is a front view schematically illustrating the internal structure of the indoor unit 1 of the air conditioning device according to Embodiment 1.
  • FIG. 3 is a side view schematically illustrating the internal structure of the indoor unit 1 of the air conditioning device according to Embodiment 1. The direction to the left in FIG. 3 illustrates the front side (that is, the indoor space side) of the indoor unit 1 .
  • a floor-mounted indoor unit 1 installed on the floor of the indoor space to be air-conditioned is illustrated as an example of the indoor unit 1 .
  • the positional relationships (such as the up-and-down relationships) between structural elements in the following description are basically those in a state in which the indoor unit 1 is installed to be usable.
  • the indoor unit 1 is provided with a housing 111 having a vertically elongated cuboid shape.
  • a housing 111 having a vertically elongated cuboid shape.
  • an air inlet 112 that sucks in the air of the indoor space is formed.
  • the air inlet 112 of the present example is lower than midway in the vertical direction of the housing 111 , and is provided at a position close to the floor.
  • On the upper front face of the housing 111 or in other words at a higher position than the height of the air inlet 112 (for example, higher than midway in the vertical direction of the housing 111 ), an air outlet 113 that blows out air sucked in from the air inlet 112 into the room is formed.
  • an operating unit not illustrated is provided above the air inlet 112 and below the air outlet 113 .
  • the operating unit an operation of starting the running of the air conditioning device, an operation of stopping the running, switching the running mode, making a set temperature and a set airflow rate, and other operations are performed by user operations.
  • the operating unit may also be provided with a display, a sound output unit, or other units that notify the user of information.
  • the housing 111 is a hollow box shape, and a frontal opening is provided in the front face of the housing 111 .
  • the housing 111 is provided with a first front panel 114 a , a second front panel 114 b , and a third front panel 114 c that are attached to the frontal opening and are removable from the frontal opening.
  • the first front panel 114 a , the second front panel 114 b , and the third front panel 114 c all have an external shape that is a substantially rectangular tabular shape.
  • the first front panel 114 a is attached to the lower part of the frontal opening of the housing 111 and is removable from the housing 111 .
  • the air inlet 112 described above is formed in the first front panel 114 a .
  • the second front panel 114 b is disposed adjacently above the first front panel 114 a , is attached to the middle part in the vertical direction of the frontal opening of the housing 111 , and is removable from the housing 111 .
  • the operating unit described above is provided on the second front panel 114 b .
  • the third front panel 114 c is disposed adjacently above the second front panel 114 b , is attached to the upper part of the frontal opening of the housing 111 , and is removable from the housing 111 .
  • the air outlet 113 described above is formed in the third front panel 114 c.
  • the interior space of the housing 111 is roughly divided into a space 115 a that serves as an air-sending section, and a space 115 b that is positioned above the space 115 a and that serves as a heat-exchanging section.
  • the space 115 a and the space 115 b are partitioned from each other by a partition 20 .
  • the partition 20 has a tabular shape, for example, and is positioned mostly horizontally.
  • an air duct opening 20 a that serves as an air duct between the space 115 a and the space 115 b is at least provided.
  • the space 115 a is configured to be exposed on the front side by removing the first front panel 114 a from the housing 111
  • the space 115 b is configured to be exposed on the front side by removing the second front panel 114 b and the third front panel 114 c from the housing 111
  • the height at which the partition 20 is installed mostly matches the height of the upper edge of the first front panel 114 a or the lower edge of the second front panel 114 b
  • the partition 20 may be formed integrally with a fan casing 108 described later, may be formed integrally with a drain pan described later, or may be formed separately from the fan casing 108 and the drain pan.
  • the indoor air-sending fan 7 f that causes a flow of air proceeding from the air inlet 112 to the air outlet 113 to be produced in an air duct 81 in the housing 111 is disposed.
  • the indoor air-sending fan 7 f of the present example is a sirocco fan provided with a motor not illustrated and an impeller 107 that is connected to the output shaft of the motor and on which multiple blades are disposed at equal intervals in the circumferential direction for example.
  • the rotation axis of the impeller 107 is disposed substantially parallel to the depth direction of the housing 111 .
  • the rotational speed of the indoor air-sending fan 7 f is set variably in multiple stages (for example, two or more stages) or is set variably and continuously, through control by the controller 30 based on the set airflow rate or other factors set by the user.
  • the impeller 107 of the indoor air-sending fan 7 f is covered by a spiral-shaped fan casing 108 .
  • the fan casing 108 is formed separately from the housing 111 for example. Close to the center of the spiral of the fan casing 108 , an air inlet opening 108 b that sucks in indoor air into the fan casing 108 through the air inlet 112 is provided. The air inlet opening 108 b is disposed to face the air inlet 112 . Also, in the tangential direction of the spiral of the fan casing 108 , an air outlet opening 108 a that blows out sent air is provided.
  • the air outlet opening 108 a is disposed to face upward, and is connected to the space 115 b through an air duct opening 20 a of the partition 20 . In other words, the air outlet opening 108 a communicates with the space 115 b through the air duct opening 20 a .
  • the open edge of the air outlet opening 108 a and the open edge of the air duct opening 20 a may be joined directly, or may be joined indirectly via a part such as a duct.
  • an electrical component box 25 housing the microcomputer that corresponds to the controller 30 , various electrical components, circuit boards, and other components, for example, is provided.
  • the load side heat exchanger 7 is disposed in the air duct 81 inside the space 115 b .
  • a drain pan (not illustrated) that receives condensed water condensed on the surface of the load side heat exchanger 7 is provided.
  • the drain pan may be formed as a part of the partition 20 , or may be formed separately from the partition 20 and disposed on the partition 20 .
  • the refrigerant detector 99 is provided.
  • an electrical refrigerant detector including an electrical gas sensor such as a semiconductor gas sensor and a hot wire semiconductor gas sensor is used.
  • the refrigerant detector 99 detects the refrigerant concentration in the air surrounding the refrigerant detector 99 , and outputs a detection signal to the controller 30 .
  • the controller 30 the presence or absence of refrigerant leakage is determined on the basis of the detection signal from the refrigerant detector 99 .
  • the parts at risk of refrigerant leakage are the brazing portion of the load side heat exchanger 7 and the fitting sections 15 a and 15 b .
  • the refrigerant used in Embodiment 1 is denser than air under atmospheric pressure. Consequently, the refrigerant detector 99 according to Embodiment 1 is provided at a position lower than the height of the load side heat exchanger 7 and the fitting sections 15 a and 15 b inside the housing 111 . With this arrangement, at least while the indoor air-sending fan 7 f is stopped, the refrigerant detector 99 is able to detect leaking refrigerant reliably. Note that in Embodiment 1, the refrigerant detector 99 is provided at a position close to the lower end of the space 115 a , but the installation position of the refrigerant detector 99 may also be at another position.
  • FIG. 4 is a flowchart illustrating one example of a refrigerant leakage detection process executed by the controller 30 of the air conditioning device according to Embodiment 1.
  • the refrigerant leakage detection process is executed repeatedly on a certain time interval while the air conditioning device is running and stopped, which corresponds to all the time, only while the air conditioning device is stopped, or only during a normal state A described later.
  • step S 1 of FIG. 4 the controller 30 acquires information about the refrigerant concentration around the refrigerant detector 99 , on the basis of the detection signal from the refrigerant detector 99 .
  • step S 2 it is determined whether or not the refrigerant concentration around the refrigerant detector 99 is equal to or greater than a preset threshold value.
  • the controller 30 determines that the refrigerant concentration is equal to or greater than the threshold value, the process proceeds to step S 3 , whereas when the controller 30 determines that the refrigerant concentration is less than the threshold value, the process ends.
  • step S 3 the running of the indoor air-sending fan 7 f is started. In the case where the indoor air-sending fan 7 f is already running, the running is continued. Also, in step S 3 , the rotational speed of the indoor air-sending fan 7 f may be set to a rotational speed capable of diffusing refrigerant sufficiently even if the amount of refrigerant leakage is a maximum (for example, a rotational speed equal to or greater than a threshold value R1 described later). This rotational speed is not limited to a rotational speed used during normal running. In step S 3 , the display, sound output unit, or other units provided on the operating unit may be used to notify the user that a leakage of refrigerant has occurred. Note that the notification will be described in detail with FIG. 5 .
  • the running of the indoor air-sending fan 7 f is started. With this process, as the leaking refrigerant can be diffused, it is possible to inhibit local increases in the refrigerant concentration in the indoor space.
  • a flammable refrigerant such as HFO-1234yf, HFO-1234ze, R290, and R1270, for example, is used as the refrigerant circulating through the refrigerant circuit 40 .
  • a flammable concentration zone for example, a zone in which the refrigerant concentration reaches the lower flammability limit (LFL) or higher
  • Embodiment 1 as the running of the indoor air-sending fan 7 f is started in the case where a leakage of refrigerant is detected, even if flammable refrigerant leaks indoors while the air conditioning device is stopped, a flammable concentration zone can be prevented from being imposed indoors.
  • FIG. 5 is a state transition diagram illustrating one example of state transitions of the air conditioning device according to Embodiment 1.
  • the states of the air conditioning device at least include a normal state A and a normal state B.
  • the normal state A and the normal state B of the present example are both states in which a leakage of refrigerant is not occurring.
  • normal running action and stopping action are performed on the basis of, for example, user operations performed on the operating unit.
  • the air conditioning device is configured to bidirectionally transition between the normal state A and the normal state B through control by the controller 30 on the basis of the rotational speed of the indoor air-sending fan 7 f .
  • a threshold value for the rotational speed used to determine state transition is stored in the ROM of the controller 30 in advance.
  • the air conditioning device while stopped is in the normal state A.
  • the refrigerant detector 99 is powered through control by the controller 30 .
  • the refrigerant detector 99 enters a working state capable of detecting refrigerant.
  • the normal state A is a state in which a leakage of refrigerant is detectable by the refrigerant detector 99 .
  • the controller 30 when the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 99 , the controller 30 causes the indoor air-sending fan 7 f to run, and issues a notification about the leakage of refrigerant.
  • the notification can be issued using at least one of the operating unit and a remote control (the remote control 27 described in Embodiment 4). Note that with regard to notifications, the same applies to embodiments described below.
  • the indoor air-sending fan 7 f is controlled to a certain rotational speed by the controller 30 .
  • the controller 30 causes the state of the air conditioning device to transition from the normal state A to the normal state B.
  • the normal state B is also a state in which a leakage of refrigerant is detectable by the refrigerant detector 99 .
  • the controller 30 disregards the detection signal from the refrigerant detector 99 , even if the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 99 . In other words, in the normal state B, the controller 30 issues no notification that refrigerant has leaked.
  • the controller 30 causes the state of the air conditioning device to transition back from the normal state B to the normal state A.
  • the threshold value R1 is set, for example, within a rotational speed range from 0 to Rmax (0 ⁇ R1 ⁇ Rmax), more preferably within a rotational speed range that is greater than 0 and less than or equal to Rmax (0 ⁇ R1 ⁇ Rmax), and even more preferably within a rotational speed range that is greater than Rmin and less than or equal to Rmax (Rmin ⁇ R1 ⁇ Rmax).
  • the threshold value R1 desirably is set to at least a rotational speed at which a flammable concentration zone is not imposed indoors even if the amount of refrigerant leakage in the indoor space is a maximum.
  • the threshold value R1 is set in anticipation of control tolerances. Also, in the case where the rotational speed of the indoor air-sending fan 7 f fluctuates depending on the load on the motor, the threshold value R1 is set in consideration of the maximum load.
  • the refrigerant detector 99 is a gas sensor such as a semiconductor gas sensor, and has a feature of reacting to hydrogen, carbon, or other substances in the atmosphere.
  • the detection signal from the refrigerant detector 99 is disregarded.
  • a flammable zone cannot be imposed.
  • Embodiment 1 under the condition of the normal state B, the detection signal from the refrigerant detector 99 is disregarded, and incorrect detection by the refrigerant detector 99 is prevented. Hypothetically, even if a leakage of refrigerant occurs in the normal state B, the detection signal from the refrigerant detector 99 is disregarded, but as the indoor air-sending fan 7 f is rotating at a rotational speed equal to or greater than the threshold value R1 in the normal state B, it is possible to diffuse the leaking refrigerant indoors.
  • Embodiment 1 even in the case where refrigerant leaks in either state of the normal state A and the normal state B, it is possible to make the indoor air-sending fan 7 f run reliably. Consequently, according to Embodiment 1, even in the unlikely case that refrigerant leaks, it is possible to inhibit local increases in the refrigerant concentration. Consequently, even in the case where a flammable refrigerant is used for example, a safer air conditioning device can be provided.
  • FIG. 6 is a diagram illustrating the relationship between the rotational speed of the indoor air-sending fan 7 f and the states of the air conditioning device in an air conditioning device according to Embodiment 2.
  • the horizontal axis represents the rotational speed of the indoor air-sending fan 7 f
  • the vertical axis represents the state of the air conditioning device.
  • a differential that serves as a dead zone of control is set between the threshold value R1 at which the air conditioning device transitions from the normal state B to the normal state A and a threshold value R2 at which the air conditioning device transitions from the normal state A to the normal state B.
  • the threshold value R2 is a value that is greater than the threshold value R1 (R2>R1).
  • the threshold values R1 and R2 are set, for example, within a rotational speed range from 0 to Rmax (0 ⁇ R1 ⁇ R2 ⁇ Rmax), more preferably within a rotational speed range that is greater than 0 and less than or equal to Rmax (0 ⁇ R1 ⁇ R2 ⁇ Rmax), and even more preferably within a rotational speed range that is greater than Rmin and less than or equal to Rmax (Rmin ⁇ R1 ⁇ R2 ⁇ Rmax).
  • the air conditioning device In the case where the air conditioning device is in the normal state A, when the rotational speed of the indoor air-sending fan 7 f becomes equal to or greater than the threshold value R2, the air conditioning device transitions from the normal state A to the normal state B. On the other hand, in the case where the air conditioning device is in the normal state B, when the rotational speed of the indoor air-sending fan 7 f becomes less than the threshold value R1, the air conditioning device transitions from the normal state B to the normal state A. Similarly to Embodiment 1 described above, in the normal state A, a notification about a leakage of refrigerant is issued, whereas in the normal state B, no notification about a leakage of refrigerant is issued.
  • Embodiment 1 in the case where the indoor air-sending fan 7 f is running at a rotational speed close to the threshold value R1, there is a possibility that the normal state A and the normal state B are switched frequently.
  • the differential is set between the threshold value R2 at which the air conditioning device transitions from the normal state A to the normal state B and the threshold value R1 at which the air conditioning device transitions from the normal state B to the normal state A. For this reason, according to Embodiment 2, it is possible to prevent frequent switching between the normal state A and the normal state B.
  • the air conditioning device includes the refrigerant circuit 40 that causes refrigerant to circulate, the indoor unit 1 that houses the load side heat exchanger 7 of the refrigerant circuit 40 and that is installed indoors, and the controller 30 that controls the indoor unit 1 , in which the indoor unit 1 is provided with the indoor air-sending fan 7 f and the refrigerant detector 99 .
  • the controller 30 When the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 99 , the controller 30 is configured to cause the indoor air-sending fan 7 f to run, and when the rotational speed of the indoor air-sending fan 7 f is equal to or greater than a first threshold value (for example, the threshold value R1 in Embodiment 1, or the threshold value R2 in Embodiment 2), the controller 30 is configured to disregard the detection signal from the refrigerant detector 99 , even if the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 99 .
  • a first threshold value for example, the threshold value R1 in Embodiment 1, or the threshold value R2 in Embodiment 2
  • the controller 30 in the normal state B, in the case where the rotational speed of the indoor air-sending fan 7 f becomes less than a second threshold value (for example, the threshold value R1 in Embodiments 1 and 2), the controller 30 is configured to issue a notification about the leakage of refrigerant.
  • the second threshold value may be equal to or less than the first threshold value.
  • FIG. 7 is a diagram schematically illustrating the configuration of the outdoor unit 2 (one example of a heat exchanger unit) of the air conditioning device according to Embodiment 3.
  • the outdoor unit 2 houses the compressor 3 , the refrigerant channel switching device 4 , the heat source side heat exchanger 5 , the pressure-reducing device 6 , the outdoor air-sending fan 5 f , and other devices, for example.
  • the compressor 3 and the outdoor air-sending fan 5 f are illustrated in FIG. 7 .
  • the rotational speed of the outdoor air-sending fan 5 f is set variably in multiple stages (for example, two or more stages) or is set variably and continuously, through control by the controller 30 .
  • the extension pipes 10 a and 10 b are connected to the outdoor unit 2 .
  • the extension pipes 10 a and 10 b are connected to refrigerant pipes inside the outdoor unit 2 via fitting sections 16 a and 16 b (for example, flare fittings).
  • the fitting sections 16 a and 16 b are disposed inside the outdoor unit 2 .
  • the fitting sections 16 a and 16 b may also be disposed outside the outdoor unit 2 .
  • the outdoor unit 2 (one example of a heat exchanger unit) according to Embodiment 3 is provided with a refrigerant detector 98 .
  • the refrigerant detector 98 is disposed inside the outdoor unit 2 and below the fitting sections 16 a and 16 b , for example.
  • the refrigerant detector 98 may also be disposed below the brazing portion of the heat source side heat exchanger 5 .
  • an electrical gas sensor such as a semiconductor gas sensor and a hot wire semiconductor gas sensor is used, for example.
  • the refrigerant detector 98 detects the refrigerant concentration in the air surrounding the refrigerant detector 98 , and outputs a detection signal to the controller 30 . In the controller 30 , the presence or absence of refrigerant leakage is determined on the basis of the detection signal from the refrigerant detector 98 .
  • the refrigerant leakage detection process according to Embodiment 3 executed by the controller 30 is obtained by substituting “refrigerant detector 99 ” with “refrigerant detector 98 ” and “indoor air-sending fan 7 f ” with “outdoor air-sending fan 5 f ” in the refrigerant leakage detection process of either Embodiment 1 or 2 described using FIGS. 4 to 6 , for example.
  • the refrigerant leakage detection process according to Embodiment 3 in the case where a leakage of refrigerant is detected by the detection signal from the refrigerant detector 98 , the running of the outdoor air-sending fan 5 f is started.
  • Embodiment 3 in a normal state B, in which the rotational speed of the outdoor air-sending fan 5 f is equal to or greater than the threshold value R1, the controller 30 is configured to disregard the detection signal from the refrigerant detector 98 , even if the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 98 . With this action, under the condition of the normal state B, it is possible to prevent incorrect detection by the refrigerant detector 98 .
  • FIG. 8 is a diagram illustrating a schematic overall configuration of a refrigeration cycle system according to Embodiment 4.
  • a separated showcase is illustrated as an example of the refrigeration cycle device included in the refrigeration cycle system.
  • the showcase includes, for example, an indoor unit 601 (one example of a load unit and also one example of a heat exchanger unit) installed in an indoor space such as inside a shop, and an outdoor unit 602 (one example of a heat source unit and also one example of a heat exchanger unit) installed in a machine room space, for example.
  • the indoor unit 601 and the outdoor unit 602 are connected via the extension pipes 10 a and 10 b .
  • an air-sending fan that works to stir air in the installation space is not provided.
  • the outdoor air-sending fan 5 f is provided.
  • the controller 30 includes an indoor unit controller provided in the indoor unit 601 and an outdoor unit controller provided in the outdoor unit 602 and capable of communication with the indoor unit controller.
  • the indoor unit controller and the outdoor unit controller are connected via a control wire 603 .
  • an air-sending fan 604 that stirs air in the indoor space is provided separately from the showcase.
  • the air-sending fan 604 is provided outside of the housing of the indoor unit 601 of the showcase.
  • the air-sending fan 604 is able to work independently of the showcase, for example.
  • the air-sending fan 604 is connected to the controller 30 (for example, the indoor unit controller) via a control wire not illustrated.
  • the rotational speed of the air-sending fan 604 is set variably in multiple stages (for example, two or more stages) or is set variably and continuously, through control by the controller 30 .
  • the air-sending fan 604 operates, the air in the indoor space is mixed together with the leaking refrigerant. With this action, as the leaking refrigerant is diffused in the indoor space, local increases in the refrigerant concentration in the indoor space are inhibited. In other words, the air-sending fan 604 serves as a leaking refrigerant diluter that dilutes the refrigerant leaking into the indoor space.
  • a refrigerant detector 605 that detects refrigerant is provided separately from the showcase.
  • the refrigerant detector 605 is provided outside of the housing of the indoor unit 601 of the showcase. As the refrigerant is denser than air under atmospheric pressure, the refrigerant detector 605 is provided close to the floor of the indoor space, for example.
  • the refrigerant detector 605 is connected to the controller 30 (for example, the indoor unit controller) via a communication wire 606 .
  • an electrical gas sensor such as a semiconductor gas sensor and a hot wire semiconductor gas sensor is used, for example.
  • the refrigerant detector 605 detects the refrigerant concentration in the air surrounding the refrigerant detector 605 , and outputs a detection signal to the controller 30 .
  • the controller 30 the presence or absence of refrigerant leakage is determined on the basis of the detection signal from the refrigerant detector 605 .
  • the controller 30 when the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 605 , the controller 30 is configured to cause the air-sending fan 604 to run and to issue a notification about the leakage of refrigerant. Also, in the normal state B, the controller 30 is configured to disregard the detection signal from the refrigerant detector 605 , even if the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 605 .
  • the threshold value R1 desirably is set to at least a rotational speed at which a flammable concentration zone is not imposed in the indoor space even if the amount of refrigerant leaking into the indoor space is a maximum.
  • a differential may be set between the threshold value R1 at which the air conditioning device transitions from the normal state B to the normal state A and the threshold value R2 at which the air conditioning device transitions from the normal state A to the normal state B.
  • an air-sending fan 607 for ventilation that exhausts the air of the machine room space into an outdoor space is provided separately from the showcase.
  • the air-sending fan 607 is provided outside of the housing of the outdoor unit 602 of the showcase (for example, in a wall facing the outdoor space from among the walls of the machine room space).
  • the air-sending fan 607 is able to work independently of the showcase, for example.
  • the air-sending fan 607 is connected to the controller 30 (for example, the outdoor unit controller) via a control wire not illustrated.
  • the rotational speed of the air-sending fan 607 is set variably in multiple stages (for example, two or more stages) or is set variably and continuously, through control by the controller 30 .
  • the air-sending fan 607 operates, the air in the machine room space is exhausted into the outdoor space together with the leaking refrigerant. With this action, as the leaking refrigerant is exhausted into the outdoor space, local increases in the refrigerant concentration in the machine room space are inhibited. In other words, the air-sending fan 607 serves as a leaking refrigerant diluter that dilutes the refrigerant leaking into the machine room space.
  • a refrigerant detector 608 that detects refrigerant is provided separately from the showcase.
  • the refrigerant detector 608 is provided outside of the housing of the outdoor unit 602 of the showcase, for example. As the refrigerant is denser than air under atmospheric pressure, the refrigerant detector 608 is provided close to the floor of the machine room space.
  • the refrigerant detector 608 is connected to the controller 30 (for example, the outdoor unit controller) via a communication wire 609 .
  • an electrical gas sensor such as a semiconductor gas sensor and a hot wire semiconductor gas sensor is used, for example.
  • the refrigerant detector 608 detects the refrigerant concentration in the air surrounding the refrigerant detector 608 , and outputs a detection signal to the controller 30 .
  • the controller 30 the presence or absence of refrigerant leakage is determined on the basis of the detection signal from the refrigerant detector 608 .
  • the controller 30 when the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 608 , the controller 30 is configured to cause the air-sending fan 607 to run and to issue a notification about the leakage of refrigerant. Also, in the normal state B, the controller 30 is configured to disregard the detection signal from the refrigerant detector 608 , even if the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 608 .
  • the threshold value R1 desirably is set to at least a rotational speed at which a flammable concentration zone is not imposed in the machine room space even if the amount of refrigerant leaking into the machine room space is a maximum.
  • a differential may be set between the threshold value R1 at which the air conditioning device transitions from the normal state B to the normal state A and the threshold value R2 at which the air conditioning device transitions from the normal state A to the normal state B.
  • FIG. 9 is a block diagram illustrating a configuration of the controller 30 of the refrigeration cycle system according to Embodiment 4.
  • the controller 30 includes an indoor unit controller 610 that is installed in the indoor unit 601 and that controls the indoor unit 601 , an outdoor unit controller 611 that is installed in the outdoor unit 602 and that controls the outdoor unit 602 , and a remote control controller 612 that is installed in the remote control 27 (for example, an operating unit provided on the indoor unit 601 ) and that controls the remote control 27 .
  • the indoor unit controller 610 is communicably connected to the outdoor unit controller 611 and the remote control controller 612 via each control wire.
  • the indoor unit controller 610 includes a control board 610 a .
  • a microcomputer 620 is mounted on the control board 610 a.
  • the outdoor unit controller 611 includes a control board 611 a .
  • a microcomputer 621 is mounted on the control board 611 a.
  • the remote control controller 612 includes a control board 612 a .
  • a microcomputer 622 is mounted on the control board 612 a.
  • the air-sending fan 604 of the present example is equipped with an air-sending fan controller 613 that controls the air-sending fan 604 .
  • the air-sending fan 607 of the present example is equipped with an air-sending fan controller 614 that controls the air-sending fan 607 .
  • the air-sending fan controller 613 is communicably connected to the indoor unit controller 610 via a control wire.
  • the air-sending fan controller 613 includes a control board 613 a .
  • a microcomputer 623 is mounted on the control board 613 a.
  • the air-sending fan controller 614 is communicably connected to the outdoor unit controller 611 via a control wire.
  • the air-sending fan controller 614 includes a control board 614 a .
  • a microcomputer 624 is mounted on the control board 614 a.
  • the controller 30 includes a sensor controller 615 that controls the refrigerant detector 605 and a sensor controller 616 that controls the refrigerant detector 608 .
  • the sensor controller 615 is communicably connected to the indoor unit controller 610 .
  • the sensor controller 615 includes a control board 615 a .
  • Each of a microcomputer 625 and the refrigerant detector 605 is permanently mounted on the control board 615 a .
  • the refrigerant detector 605 of the present example is mounted directly onto the control board 615 a , but it is sufficient for the refrigerant detector 605 to be permanently connected to the control board 615 a .
  • the refrigerant detector 605 may be provided at a position distanced from the control board 615 a , and wires from the refrigerant detector 605 may be connected to the control board 615 a by soldering or another method.
  • the control board 615 a is provided separately from the control board 610 a , but the control board 615 a may be omitted, and the refrigerant detector 605 may be permanently connected to the control board 610 a.
  • the sensor controller 616 is communicably connected to the outdoor unit controller 611 .
  • the sensor controller 616 includes a control board 616 a .
  • Each of a microcomputer 626 and the refrigerant detector 608 is permanently mounted on the control board 616 a .
  • the refrigerant detector 608 of the present example is mounted directly onto the control board 616 a , but it is sufficient for the refrigerant detector 608 to be permanently connected to the control board 616 a .
  • the refrigerant detector 608 may be provided at a position distanced from the control board 616 a , and wires from the refrigerant detector 608 may be connected to the control board 616 a by soldering or another method.
  • the control board 616 a is provided separately from the control board 611 a , but the control board 616 a may be omitted, and the refrigerant detector 608 may be permanently connected to the control board 611 a.
  • Each of the microcomputer 625 of the sensor controller 615 and the microcomputer 626 of the sensor controller 616 has a rewritable non-volatile memory.
  • Each non-volatile memory is provided with a leakage history bit (one example of a leakage history storage area) with which a history of refrigerant leakage is stored. It is possible to set the leakage history to “0” or “1”.
  • the value “0” of the leakage history bit represents a state with no refrigerant leakage history, while “1” represents a state with a refrigerant leakage history.
  • the initial value of the leakage history bit is “0”.
  • each leakage history bit is set to “0”.
  • the leakage history bit of the microcomputer 625 is rewritten from “0” to “1”.
  • the leakage history bit of the microcomputer 626 is rewritten from “0” to “1”.
  • the leakage history bits of the microcomputers 625 and 626 are both irreversibly rewritable in only one direction from “0” to “1”. Also, the leakage history bits of the microcomputers 625 and 626 are maintained regardless of whether or not power is supplied to the microcomputers 625 and 626 .
  • Each memory of the microcomputers 620 , 621 , and 622 of the corresponding one of the indoor unit 601 , the outdoor unit 602 , and the remote control 27 is provided with a first leakage history bit that corresponds to the leakage history bit of the microcomputer 625 and a second leakage history bit that corresponds to the leakage history bit of the microcomputer 626 .
  • These leakage history bits may be set to “0” or “1”, and are bidirectionally rewritable between “0” and “1”.
  • the value of the first leakage history bit of each of the microcomputers 620 , 621 , and 622 is set to the same value as the leakage history bit of the microcomputer 625 acquired by communication.
  • the value of the second leakage history bit of each of the microcomputers 620 , 621 , and 622 is set to the same value as the leakage history bit of the microcomputer 626 acquired by communication. Even if the first leakage history bit and the second leakage bit of the microcomputers 620 , 621 , and 622 are reverted to an initial value (“0” for example) when the supply of power is cut off, the first and second leakage history bits are set back to the same values as the leakage history bits of the microcomputers 625 and 626 when the supply of power is resumed.
  • the indoor unit controller 610 executes a normal control of the indoor unit 601 when the first leakage history bit and the second leakage history bit of the microcomputer 620 are both set to “0”.
  • the indoor unit 601 in this state executes normal running action and stopping action on the basis of operations on the remote control 27 or another device.
  • the indoor unit controller 610 executes a control via the air-sending fan controller 613 that forcibly causes the air-sending fan 604 to run, for example.
  • the outdoor unit controller 611 executes a normal control of the outdoor unit 602 when the first leakage history bit and the second leakage history bit of the microcomputer 621 are both set to “0”.
  • the outdoor unit controller 611 executes a control that causes the compressor 3 to stop, for example.
  • the compressor 3 remains stopped as long as the first leakage history bit or the second leakage history bit of the microcomputer 621 is still set to “1”.
  • the outdoor unit controller 611 executes a control via the air-sending fan controller 614 that forcibly causes the air-sending fan 607 to run, for example.
  • the outdoor unit controller 611 additionally may execute a control that forcibly causes the outdoor air-sending fan 5 f to run.
  • the remote control controller 612 executes a normal control of the remote control 27 when the first leakage history bit and the second leakage history bit of the microcomputer 622 are both set to “0”.
  • the remote control controller 612 displays information including the type of abnormality or a troubleshooting method on a display provided in the remote control 27 , for example.
  • the remote control controller 612 may also display information about the refrigerant leakage location on the display, on the basis of which one of the first leakage history bit and the second leakage history bit is set to “1”.
  • the remote control controller 612 may also cause a sound output unit provided in the remote control 27 to issue a notification by sound of information about the type of abnormality, a troubleshooting method, or the refrigerant leakage location.
  • a leakage history of refrigerant is irreversibly written to the non-volatile memory of the control boards 615 a and 616 a .
  • To reset the leakage history of refrigerant it is necessary to replace the control board 615 a or 616 a with a control board having no leakage history.
  • the permanently connected refrigerant detectors 605 and 608 are also replaced. Consequently, it is possible to prevent continued use of the refrigerant detectors 605 and 608 whose detection characteristics have changed due to being exposed to a refrigerant environment.
  • Embodiment 4 as the running of the showcase cannot be resumed unless the control boards 615 a and 616 a are replaced, it is possible to prevent the running of a showcase having a location of the refrigerant leakage yet to be repaired from being resumed due to human error or on purpose.
  • the controller 30 in the normal state B in which the rotational speed of the air-sending fan 604 is equal to or greater than the threshold value R1, the controller 30 is configured to disregard the detection signal from the refrigerant detector 605 , even if the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 605 . With this action, under the condition of the normal state B, it is possible to prevent incorrect detection by the refrigerant detector 605 .
  • the detection signal from the refrigerant detector 605 is disregarded, but as the air-sending fan 604 is rotating at a rotational speed equal to or greater than the threshold value R1 in the normal state B, it is possible to diffuse the leaking refrigerant in the indoor space.
  • the controller 30 in the normal state B in which the rotational speed of the air-sending fan 607 is equal to or greater than the threshold value R1, the controller 30 is configured to disregard the detection signal from the refrigerant detector 608 , even if the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector 608 . With this action, under the condition of the normal state B, it is possible to prevent incorrect detection by the refrigerant detector 608 .
  • the detection signal from the refrigerant detector 608 is disregarded, but as the air-sending fan 607 is rotating at a rotational speed equal to or greater than the threshold value R1 in the normal state B, it is possible to exhaust the refrigerant leaking into the machine room space to the outdoor space.
  • the first leakage history bit and the second leakage history bit are provided only in the memory of each of the microcomputers 620 , 621 , and 622 of the corresponding one of the indoor unit 601 , the outdoor unit 602 , and the remote control 27 , but the first leakage history bit and the second leakage history bit may also be provided in the memory of each of the microcomputer 623 of the air-sending fan 604 and the microcomputer 624 of the air-sending fan 607 .
  • the air-sending fan 604 includes the air-sending fan controller 613 and the air-sending fan 607 includes the air-sending fan controller 614
  • the air-sending fan 604 is connected to the indoor unit 601 via a control wire and the air-sending fan 607 is connected to the outdoor unit 602 via a control wire.
  • the air-sending fans 604 and 607 do not include controllers, for example, the air-sending fan 604 is connected to the indoor unit 601 via a power wire and the air-sending fan 607 is connected to the outdoor unit 602 via a power wire.
  • control of the running and stopping of the air-sending fan 604 is executed by relay control in the control board 610 a of the indoor unit controller 610
  • control of the running and stopping of the air-sending fan 607 is executed by relay control in the control board 611 a of the outdoor unit controller 611 .
  • a leakage history bit with which the presence or absence of a leakage history with a single bit is stored is illustrated as an example of a leakage history storage area provided in non-volatile memory, but the configuration is not limited to this illustration.
  • a leakage history storage area of 2 bits or more may also be provided in the non-volatile memory.
  • the leakage history storage area one of either first information representing a state with no refrigerant leakage history and second information representing a state with refrigerant leakage history is selectively stored.
  • the information stored in the leakage history storage area is changeable in only one direction from the first information to the second information.
  • the controller 30 detects a leakage of refrigerant
  • the controller 30 is configured to change the information stored in the leakage history storage area from the first information to the second information.
  • the refrigerant detector and the air-sending fan may also be provided separately from the refrigeration cycle device when the refrigerant detector and the air-sending fan are communicably connected to the refrigeration cycle device via control wires or another element, or remotely operably connected to the refrigeration cycle device via power wires.
  • Embodiment 4 in the case where a refrigerant detector and an air-sending fan are installed in each of the installation location of the indoor unit and the installation location of the outdoor unit, it is sufficient to run only the air-sending fan in the space where a leakage of refrigerant is detected. In other words, in the case where a leakage of refrigerant is detected by the refrigerant detector provided in the installation location of the indoor unit, it is sufficient to run only the air-sending fan provided in the installation location of the indoor unit. In the case where a leakage of refrigerant is detected by the refrigerant detector provided in the installation location of the outdoor unit, it is sufficient to run only the air-sending fan provided in the installation location of the outdoor unit.
  • the air-sending fan 604 that stirs the air in the indoor space is provided in the indoor space and the air-sending fan 607 that exhausts the air in the machine room space into the outdoor space is provided in the machine room space, but the configuration is not limited to this description.
  • an air-sending fan for ventilation that exhausts air in the indoor space into the outdoor space may also be provided in the indoor space
  • an air-sending fan that stirs the air in the machine room space may also be provided in the machine room space.
  • the refrigeration cycle device is provided with the refrigerant circuit 40 that causes refrigerant to circulate, heat exchanger units (for example, the indoor unit 1 and the outdoor unit 2 ) that house the heat exchangers (for example, the load side heat exchanger 7 and the heat source side heat exchanger 5 ) of the refrigerant circuit 40 , and the controller 30 that controls the heat exchanger units.
  • Each heat exchanger unit includes an air-sending fan (for example, the indoor air-sending fan 7 f and the outdoor air-sending fan 5 f ) and a refrigerant detector (for example, the refrigerant detectors 98 and 99 ).
  • the controller 30 is configured to cause the air-sending fan to run when the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector.
  • a first threshold value for example, the threshold value R1 of Embodiment 1 or the threshold value R2 of Embodiment 2
  • the controller 30 is configured to disregard the detection signal from the refrigerant detector, even if the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector.
  • the controller 30 in the normal state B, in the case where the rotational speed of the air-sending fan becomes less than a second threshold value (for example, the threshold value R1 in Embodiments 1 and 2), the controller 30 is configured to issue a notification about the leakage of refrigerant.
  • the second threshold value may be equal to or less than the first threshold value.
  • the heat exchanger may be the load side heat exchanger 7 or the heat source side heat exchanger 5 of the refrigerant circuit 40 .
  • the refrigeration cycle system is provided with a refrigeration cycle device including the refrigerant circuit 40 that causes refrigerant to circulate and the controller 30 that controls the refrigerant circuit 40 , air-sending fans (for example, the air-sending fans 604 and 607 ) controlled by the controller 30 , and refrigerant detectors (for example, the refrigerant detectors 605 and 608 ) that detect refrigerant and output a detection signal to the controller 30 .
  • the controller 30 is configured to cause the air-sending fan to run when the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector.
  • the controller 30 is configured to disregard the detection signal from the refrigerant detector, even if the controller 30 detects a leakage of refrigerant on the basis of the detection signal from the refrigerant detector.
  • a first threshold value for example, the threshold value R1 of Embodiment 1 or the threshold value R2 of Embodiment 2
  • the controller 30 in the normal state B, in the case where the rotational speed of the air-sending fan becomes less than a second threshold value (for example, the threshold value R1 in Embodiments 1 and 2), the controller 30 is configured to issue a notification about the leakage of refrigerant.
  • the second threshold value may be equal to or less than the first threshold value.
  • Embodiments 1 to 4 described above, and various modifications are possible.
  • an embodiment described above gives a floor-mounted indoor unit as an example of the indoor unit 1 , but the present invention is also applicable to other indoor units, such as a ceiling cassette type, a ceiling-embedded type, a hanging type, and a wall-mounted type.
  • an embodiment described above gives an air conditioning device or a showcase as an example of the refrigeration cycle device, but the present invention is also applicable to other refrigeration cycle devices, such as a heat pump water heater (for example, the heat pump device described in Japanese Unexamined Patent Application Publication No. 2016-3783) and a chiller that is often installed in a machine room.
  • a heat pump water heater for example, the heat pump device described in Japanese Unexamined Patent Application Publication No. 2016-3783
  • a chiller that is often installed in a machine room.
  • an embodiment described above gives a semiconductor gas sensor or a hot wire semiconductor gas sensor as an example of the refrigerant detector, but the configuration is not limited to this example.
  • Another refrigerant detector such as an infrared detector, may be used.

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US11236927B2 (en) * 2018-02-23 2022-02-01 Mitsubishi Electric Corporation Indoor system and indoor unit of air-conditioning apparatus
US20220244129A1 (en) * 2021-01-29 2022-08-04 Huawei Digitial Power Technologies Co., Ltd. Leakage detection apparatus and leakage detection method
US20230175755A1 (en) * 2021-12-08 2023-06-08 Eppendorf Se Method For Operating An Item of Laboratory Equipment Cooled By Means Of A Flammable Refrigerant
US11704447B2 (en) * 2019-03-12 2023-07-18 Mitsubishi Electric Research Laboratories, Inc. Method and system for circuiting in heat exchangers

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WO2020226091A1 (ja) * 2019-05-08 2020-11-12 ダイキン工業株式会社 空調システム
JP6840906B1 (ja) * 2020-06-18 2021-03-10 三菱電機ビルテクノサービス株式会社 冷媒回収システム及び冷媒回収方法
JP7474923B2 (ja) * 2020-06-25 2024-04-26 パナソニックＩｐマネジメント株式会社 空気調和機
US11125457B1 (en) * 2020-07-16 2021-09-21 Emerson Climate Technologies, Inc. Refrigerant leak sensor and mitigation device and methods
KR102251194B1 (ko) * 2020-11-06 2021-05-13 주식회사 시스웍스 가축사용 히트펌프 냉난방시스템
CN114543332B (zh) * 2020-11-26 2024-02-20 广东美的制冷设备有限公司 冷媒泄漏的检测方法、空调器及计算机存储介质
JP7189468B2 (ja) 2021-01-08 2022-12-14 ダイキン工業株式会社 不具合箇所推定システム、不具合箇所推定方法、及びプログラム
US20230020905A1 (en) * 2021-07-14 2023-01-19 Carrier Corporation Methods of reducing the occurance of false positives in gas detectors

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JP5939292B2 (ja) * 2014-10-31 2016-06-22 ダイキン工業株式会社 空気調和機
JP6222252B2 (ja) * 2015-03-30 2017-11-01 ダイキン工業株式会社 空気調和装置の室内機
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US11098916B2 (en) * 2017-05-24 2021-08-24 Mitsubishi Electric Corporation Air conditioning system
US11236927B2 (en) * 2018-02-23 2022-02-01 Mitsubishi Electric Corporation Indoor system and indoor unit of air-conditioning apparatus
US20200124306A1 (en) * 2018-10-17 2020-04-23 Lennox Industries Inc. Refrigerant pump down for an hvac system
US10767882B2 (en) * 2018-10-17 2020-09-08 Lennox Industries Inc. Refrigerant pump down for an HVAC system
US11704447B2 (en) * 2019-03-12 2023-07-18 Mitsubishi Electric Research Laboratories, Inc. Method and system for circuiting in heat exchangers
US20220244129A1 (en) * 2021-01-29 2022-08-04 Huawei Digitial Power Technologies Co., Ltd. Leakage detection apparatus and leakage detection method
US20230175755A1 (en) * 2021-12-08 2023-06-08 Eppendorf Se Method For Operating An Item of Laboratory Equipment Cooled By Means Of A Flammable Refrigerant

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WO2018158912A1 (ja) 2018-09-07
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CN110366665A (zh) 2019-10-22
JP6797278B2 (ja) 2020-12-09
JPWO2018158912A1 (ja) 2019-11-07

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