EP3705808A1 - Air conditioner - Google Patents
Air conditioner Download PDFInfo
- Publication number
- EP3705808A1 EP3705808A1 EP18873146.7A EP18873146A EP3705808A1 EP 3705808 A1 EP3705808 A1 EP 3705808A1 EP 18873146 A EP18873146 A EP 18873146A EP 3705808 A1 EP3705808 A1 EP 3705808A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- compressor
- protection control
- temperature
- operating frequency
- target frequency
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000010438 heat treatment Methods 0.000 claims abstract description 89
- 238000001816 cooling Methods 0.000 claims abstract description 79
- 101000603323 Homo sapiens Nuclear receptor subfamily 0 group B member 1 Proteins 0.000 claims description 6
- 102100039019 Nuclear receptor subfamily 0 group B member 1 Human genes 0.000 claims description 6
- 102100021405 ATP-dependent RNA helicase DDX1 Human genes 0.000 claims description 5
- 101001041697 Homo sapiens ATP-dependent RNA helicase DDX1 Proteins 0.000 claims description 5
- 230000004913 activation Effects 0.000 abstract description 35
- 239000003507 refrigerant Substances 0.000 description 51
- 239000007788 liquid Substances 0.000 description 13
- 238000005259 measurement Methods 0.000 description 7
- 238000011022 operating instruction Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- 238000004891 communication Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 230000003213 activating effect Effects 0.000 description 4
- 238000005187 foaming Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000005057 refrigeration Methods 0.000 description 1
Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- 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
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- 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
- F25B13/00—Compression machines, plants or systems, with reversible cycle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2500/00—Problems to be solved
- F25B2500/06—Damage
-
- 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
- F25B2500/26—Problems to be solved characterised by the startup of the refrigeration 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
- 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
- F25B2600/07—Remote controls
-
- 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
- F25B2700/2104—Temperatures of an indoor room or compartment
-
- 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
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21152—Temperatures of a compressor or the drive means therefor at the discharge side of the compressor
Definitions
- the present disclosure relates to an air conditioner.
- a typical air conditioner When starting a cooling or heating operation, a typical air conditioner performs an activation operation that lowers the operating frequency of a compressor for a predetermined time from when the compressor is activated in order to prevent backflow of liquid to the compressor (for example, refer to Patent Document 1).
- Patent Document 1 Japanese Laid-Open Patent Publication No. 6-341720
- the liquid backflow to the compressor does not always occur. More specifically, the probability of occurrence of the liquid backflow to the compressor may be low depending on the surrounding environment of the compressor at a time of starting the cooling or heating operation.
- the activation operation that lowers the operating frequency of the compressor is performed even in such a case, the time from when the compressor is activated to when the room temperature reaches the set temperature extends. This hinders a quick startup of the cooling or heating operation.
- an air conditioner includes a compressor in which an operating frequency is changeable and a control unit that executes a compressor protection control.
- the compressor protection control increases the operating frequency of the compressor to a necessary operating frequency when starting a cooling operation or a heating operation.
- the compressor protection control includes a first protection control and a second protection control.
- the first protection control controls the operating frequency so that a time from when the compressor is activated to when the operating frequency reaches the necessary operating frequency is relatively long.
- the second protection control controls the operating frequency so that the time from when the compressor is activated to when the operating frequency reaches the necessary operating frequency is relatively short.
- the second protection control is executed. This shortens the time from when the compressor 11 is activated to when the operating frequency of the compressor 11 reaches the necessary operating frequency FN. As a result, the time from when the cooling or heating operation is started to when the room temperature DA reaches the set temperature is shortened, and the cooling or heating operation starts up quickly.
- the predetermined condition refers to a condition that lowers the probability of occurrence of problems with the compressor caused by sudden increases in the operating frequency of the compressor when activated, such as a rise in the degree of dilution caused by a lowered surface of oil in the compressor or a returned refrigerant, backflow of liquid to the compressor, freezing of the outdoor heat exchanger and the indoor heat exchanger used as evaporators, and negative pressure of the suction side of the compressor.
- the control unit sets a first target frequency and a second target frequency in the compressor protection control.
- the second target frequency is greater than the first target frequency and is less than the necessary operating frequency.
- the control unit maintains the operating frequency at the first target frequency for a first period and at the second target frequency for a second period so that the operating frequency is increased in a stepped manner.
- the first target frequency of the second protection control is greater than the first target frequency of the first protection control.
- the second target frequency of the second protection control is greater than the second target frequency of the first protection control.
- the second protection control shortens the time from when the compressor is activated to when the operating frequency of the compressor reaches the necessary operating frequency. Thus, the cooling or heating operation starts up quickly.
- the control unit sets a first target frequency and a second target frequency in the compressor protection control.
- the second target frequency is greater than the first target frequency and is less than the necessary operating frequency.
- the control unit maintains the operating frequency at the first target frequency for a first period and at the second target frequency for a second period so that the operating frequency is increased in a stepped manner.
- the first period of the second protection control is shorter than the first period of the first protection control.
- the second period of the second protection control is shorter than the second period of the second protection control.
- the second protection control shortens the time from when the compressor is activated to when the operating frequency of the compressor reaches the necessary operating frequency. Thus, the cooling or heating operation starts up quickly.
- the predetermined condition in the heating operation differs from the predetermined condition in the cooling operation.
- the second protection control is appropriately executed in the cooling or heating operation.
- the predetermined condition includes an indoor air temperature, an outdoor air temperature, and a temperature difference between the indoor air temperature and the outdoor air temperature.
- the predetermined condition in the heating operation is that the indoor air temperature is less than or equal to a room temperature threshold value, that the outdoor air temperature is greater than or equal to an outdoor temperature threshold value, and that the temperature difference between the indoor air temperature and the outdoor air temperature is less than or equal to a temperature difference threshold value.
- the indoor air temperature and the outdoor air temperature which are easily obtained information about the air conditioner, are used to set the condition that limits occurrence of problems with the compressor such as backflow of liquid to the compressor in the compressor protection control.
- the predetermined condition includes a temperature of a discharge pipe of the compressor and an outdoor air temperature.
- the second protection control is more appropriately executed in the cooling or heating operation.
- the air conditioner 1 includes a refrigerant circuit 40.
- the refrigerant circuit 40 includes a refrigerant pipe 30 that circulates a refrigerant between an outdoor unit 10 and an indoor unit 20.
- the air conditioner 1 of the present embodiment includes the refrigerant circuit 40 formed by connecting the refrigerant pipe 30 to the outdoor unit 10, which is installed outdoors, and the indoor unit 20, which is a wall-installation type and is installed on an indoor wall surface or the like.
- the outdoor unit 10 includes, for example, a compressor 11 in which the operating frequency is changeable, a four-way switching valve 12, an outdoor heat exchanger 13, an expansion valve 14, an outdoor fan 15, and an outdoor controller 16.
- the outdoor fan 15 includes a motor 15a and an impeller 15b connected to the output shaft of the motor 15a.
- the motor 15a is a drive source having a changeable rotational speed.
- An example of the impeller 15b is a propeller fan.
- the compressor 11 is, for example, a rocking piston compressor and includes, for example, a compression mechanism, a motor, and a crankshaft that transmits driving power of the motor to the compression mechanism (none shown).
- the compressor 11 includes an accumulator 11a that separates the refrigerant into gas and liquid.
- An example of the motor is a three-phase brushless motor.
- the expansion valve 14 is, for example, an electronic expansion valve.
- the outdoor fan 15 rotates the impeller 15b using the motor 15a to facilitate heat exchange between the outdoor air and the refrigerant flowing through a heat transfer tube of the outdoor heat exchanger 13. Thus, the outdoor fan 15 generates a flow of outdoor air that passes through the outdoor heat exchanger 13.
- the outdoor controller 16 is electrically connected to the motor of the compressor 11, the four-way switching valve 12, the expansion valve 14, and the motor 15a of the outdoor fan 15.
- the indoor unit 20 includes, for example, an indoor heat exchanger 21, an indoor fan 22, and an indoor controller 23.
- the indoor fan 22 includes a motor 22a and an impeller (not shown) connected to the output shaft of the motor 22a.
- the motor 22a is a drive source having a changeable rotational speed.
- An example of the impeller is a crossflow fan.
- the indoor fan 22 rotates the impeller using the motor 22a to facilitate heat exchange between the indoor air and the refrigerant flowing through a heat transfer tube of the indoor heat exchanger 21.
- the indoor controller 23 is electrically connected to the motor 22a of the indoor fan 22.
- the indoor controller 23 is, for example, configured to perform wireless communication with a remote controller 51 (refer to Fig. 2 ) of the air conditioner 1 using infrared light or the like.
- the indoor controller 23 is configured to perform wired communication with the outdoor controller 16 through a signal line.
- the indoor controller 23 controls the indoor unit 20, and the outdoor controller 16 controls the outdoor unit 10 based on an operating instruction of the remote controller 51.
- the refrigerant circuit 40 is configured by connecting the compressor 11, the four-way switching valve 12, the outdoor heat exchanger 13, the expansion valve 14, and the indoor heat exchanger 21 with the refrigerant pipe 30 as a loop.
- the refrigerant circuit 40 is configured to execute a vapor compression refrigeration cycle that reversibly circulates the refrigerant by switching the four-way switching valve 12.
- the refrigerant circuit 40 forms a cooling cycle in which the refrigerant circulates in the order of the compressor 11, the four-way switching valve 12, the outdoor heat exchanger 13, the expansion valve 14, the indoor heat exchanger 21, the four-way switching valve 12, and the compressor 11.
- the air conditioner 1 performs the cooling operation in which the outdoor heat exchanger 13 acts as a condenser and the indoor heat exchanger 21 acts as an evaporator.
- the refrigerant circuit 40 forms a heating cycle in which the refrigerant circulates in the order of the compressor 11, the four-way switching valve 12, the indoor heat exchanger 21, the expansion valve 14, the outdoor heat exchanger 13, the four-way switching valve 12, and the compressor 11.
- the air conditioner 1 performs the heating operation in which the indoor heat exchanger 21 acts as a condenser and the outdoor heat exchanger 13 acts as an evaporator.
- a control unit 50 that controls the air conditioner 1 includes the outdoor controller 16 and the indoor controller 23.
- Each of the outdoor controller 16 and the indoor controller 23 includes, for example, a storage device and an arithmetic processing device that executes a predetermined control program.
- the arithmetic processing device includes, for example, a central processing unit (CPU) or a micro processing unit (MPU).
- the storage unit stores various control programs and information used for various control processes.
- the storage device includes, for example, a nonvolatile memory and a volatile memory.
- the control unit 50 is connected to the remote controller 51, an indoor temperature sensor 52, an outdoor temperature sensor 53, and a discharge pipe temperature sensor 54 so that communication is performed.
- control unit 50 is configured to perform wireless communication with the remote controller 51 (refer to Fig. 3 ) using, for example, infrared light. More specifically, the remote controller 51 transmits signals of an operating instruction (instruction to perform cooling operation, heating operation, etc.) and a deactivating instruction to the control unit 50.
- the indoor temperature sensor 52, the outdoor temperature sensor 53, and the discharge pipe temperature sensor 54 are electrically connected to the control unit 50.
- the indoor temperature sensor 52 is used to measure the indoor air temperature (room temperature) and is disposed, for example, in the vicinity of an inlet of the indoor unit 20.
- the indoor temperature sensor 52 transmits a signal corresponding to the room temperature to the control unit 50.
- the outdoor temperature sensor 53 is used to measure the outdoor air temperature (outdoor temperature) and is disposed, for example, in the vicinity of an inlet of the outdoor unit 10.
- the outdoor temperature sensor 53 transmits a signal corresponding to the outdoor temperature to the control unit 50.
- the discharge pipe temperature sensor 54 is used to measure the temperature of a discharge pipe of the compressor 11, that is, the temperature of a discharged gas refrigerant discharged from the compressor 11.
- the discharge pipe temperature sensor 54 is attached to the discharge pipe of the compressor 11.
- the discharge pipe temperature sensor 54 transmits a signal corresponding to the temperature of the gas refrigerant discharged from the compressor 11 to the control unit 50.
- the control unit 50 receives various signals (operating instruction and measurement information) from the remote controller 51, the indoor temperature sensor 52, the outdoor temperature sensor 53, and the discharge pipe temperature sensor 54.
- the control unit 50 obtains the room temperature (hereafter, referred to as "room temperature DA") based on measurement information of the indoor temperature sensor 52, obtains the outdoor temperature (hereafter, referred to as "ambient temperature DOA”) based on measurement information of the outdoor temperature sensor 53, and obtains a temperature DF of the discharge pipe of the compressor 11 (temperature of discharged gas refrigerant) based on measurement information of the discharge pipe temperature sensor 54.
- room temperature DA room temperature
- ambient temperature DOA outdoor temperature
- a temperature DF of the discharge pipe of the compressor 11 temperature of discharged gas refrigerant
- the indoor controller 23 Since the indoor controller 23 is electrically connected to the outdoor controller 16, the operating instruction and the room temperature DA, which are received by the indoor controller 23, may be transmitted to the outdoor controller 16. Also, the ambient temperature DOA and the temperature DF of the discharge pipe of the compressor 11, which are received by the outdoor controller 16, may be transmitted to the indoor controller 23.
- the indoor controller 23 controls the rotational speed of the motor 22a of the indoor fan 22 based on an operating instruction of the remote controller 51 and measurement information.
- the outdoor controller 16 controls the operating frequency of the compressor 11, the switching of the four-way switching valve 12 between the cooling mode connection state and the heating mode connection state, the opening degree of the expansion valve 14, and the rotational speed of the motor 15a of the outdoor fan 15 based on an operating instruction of the remote controller 51 and measurement information.
- the control unit 50 executes the cooling operation and the heating operation through the indoor controller 23 and the outdoor controller 16 based on an operating instruction of the remote controller 51 and measurement information. In the cooling operation and the heating operation, the control unit 50 controls the compressor 11, the expansion valve 14, the outdoor fan 15, and the indoor fan 22 so that the indoor temperature reaches the temperature set by the remote controller 51.
- the control unit 50 sets an increase rate at which the operating frequency of the compressor 11 is increased and a decrease rate at which the operating frequency is decreased so that the increase rate is equal to the decrease rate.
- An example of the increase rate and the decrease rate, which are change rates of the operating frequency of the compressor 11 in the cooling operation and the heating operation, is 2 Hz per second.
- the control unit 50 when activating the compressor 11 to start the cooling or heating operation, the control unit 50 increases the low operating frequency of the compressor 11 to an operating frequency necessary for the cooling or heating operation (hereafter, referred to as "necessary operating frequency FN"). In this case, the control unit 50 executes a compressor protection control when activating the compressor 11.
- the compressor protection control in order to prevent problems with the compressor 11, the operating frequency of the compressor 11 is low at the beginning and is increased in a stepped manner as time elapses to the necessary operating frequency FN, at which the compressor 11 stably operates.
- Examples of problems with the compressor 11 caused by sudden increases in the operating frequency of the compressor 11 when activated include a rise in the degree of dilution caused by a lowered surface of oil in the compressor 11 or a returned refrigerant, backflow of liquid to the compressor 11, freezing of the outdoor heat exchanger 13 and the indoor heat exchanger 21 used as evaporators, and negative pressure of the suction side of the compressor 11.
- Graph GX indicated by the broken line in Fig. 3 is a schematic graph showing a typical compressor protection control.
- the operating frequency of the compressor 11 is changed so that the operating frequency is maintained at multistage target frequencies for a predetermined time before reaching the necessary operating frequency FN. More specifically, in the compressor protection control, the control unit 50 stores a first target frequency FX1, a second target frequency FX2 that is greater than the first target frequency FX1, a third target frequency FX3 that is greater than the second target frequency FX2, and a fourth target frequency FX4 that is greater than the third target frequency FX3. At time t1, the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 reaches the first target frequency FX1.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 is maintained at the first target frequency FX1.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 changes from the first target frequency FX1 to the second target frequency FX2.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 is maintained at the second target frequency FX2.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 changes from the second target frequency FX2 to the third target frequency FX3.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 is maintained at the third target frequency FX3.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 changes from the third target frequency FX3 to the fourth target frequency FX4. From time t6 to time t7, the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 is maintained at the fourth target frequency FX4. At time t7, the control unit 50 drives the compressor so that the operating frequency of the compressor 11 changes from the fourth target frequency FX4 to the necessary operating frequency FN.
- the difference (FX2-FX1) between the second target frequency FX2 and the first target frequency FX1, the difference (FX3-FX2) between the third target frequency FX3 and the second target frequency FX2, and the difference (FX4-FX3) between the fourth target frequency FX4 and the third target frequency FX3 are equal to each other.
- a second period TX2 during which the second target frequency FX2 is maintained and a third period TX3 during which the third target frequency FX3 is maintained
- a fourth period TX4 during which the fourth target frequency FX4 is maintained are equal to each other.
- the probability of occurrence of problems with the compressor 11 may be low depending on the surrounding environment (outdoor air temperature and indoor air temperature) of the compressor 11.
- the probability of occurrence of problems with the compressor 11 is low, if the compressor protection control indicated by graph GX shown in Fig. 3 is executed, the compressor 11 is operated with a low cooling performance or a low heating performance even though problems with the compressor 11 is not likely to occur.
- the control unit 50 executes a first activation control that changes the mode of the compressor protection control based on whether the probability of occurrence of problems with the compressor 11 is high or low. More specifically, when the probability of occurrence of problems with the compressor 11 is high, the control unit 50 executes a first protection control, that is, the compressor protection control indicated by graph GX shown in Fig. 3 . When the probability of occurrence of problems with the compressor 11 is low, the control unit 50 executes a second protection control. The second protection control increases the operating frequency of the compressor 11 to the necessary operating frequency FN more quickly than the compressor protection control (first protection control) indicated by graph GX shown in Fig. 3 .
- the second protection control has a first target frequency FA1 and a second target frequency FA2. That is, the number of target frequencies of the second protection control is less than the number of target frequencies of the first protection control.
- the first target frequency FA1 is greater than the first target frequency FX1 of the first protection control.
- the first target frequency FA1 is equal to the second target frequency FX2 of graph GX.
- the second target frequency FA2 is greater than the second target frequency FX2 of the first protection control.
- the second target frequency FA2 is greater than the fourth target frequency FX4 of graph GX and is less than the necessary operating frequency FN.
- the first target frequency FA1 is equal to the difference (FA2-FA1) between the second target frequency FA2 and the first target frequency FA1.
- the difference (FA2-FA1) between the second target frequency FA2 and the first target frequency FA1 is greater than the difference (FN-FA2) between the necessary operating frequency FN and the second target frequency FA2.
- a first period TA1 during which the operating frequency of the compressor 11 is maintained at the first target frequency FA1 is equal to a second period TA2 during which the operating frequency of the compressor 11 is maintained at the second target frequency FA2.
- the control unit 50 controls the operating frequency of the compressor 11 to be maintained at the first target frequency FA1 for a predetermined time. Subsequently, the control unit 50 controls the operating frequency of the compressor 11 to change from the first target frequency FA1 to the second target frequency FA2. After controlling the operating frequency of the compressor 11 to be maintained at the second target frequency FA2 for a predetermined time, the control unit 50 controls the operating frequency of the compressor 11 to change from the second target frequency FA2 to the necessary operating frequency FN.
- the first period TA1 in which the operating frequency of the compressor 11 is controlled to be maintained at the first target frequency FA1 in the second protection control, is shorter than the first period TX1, in which the operating frequency of the compressor 11 is controlled to be maintained at the first target frequency FX1 in the first protection control.
- Graph GA shown in Fig. 3 shows changes in the operating frequency of the compressor 11 in the second protection control.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 reaches the first target frequency FA1.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 is maintained at the first target frequency FA1.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 changes from the first target frequency FA1 to the second target frequency FA2.
- time t2 to time t4 (during the period TA2), the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 is maintained at the second target frequency FA2.
- the control unit 50 drives the compressor 11 so that the operating frequency of the compressor 11 changes from the second target frequency FA2 to the necessary operating frequency FN.
- a period TA (from time t1 to time t4) from when the compressor 11 is activated to when the operating frequency of the compressor 11 reaches the necessary operating frequency FN in the second protection control is shorter than a period TX (from time t1 to time t8) from when the compressor 11 is activated to when the operating frequency of the compressor 11 reaches the necessary operating frequency FN in the first protection control.
- the probability of occurrence of problems with the compressor 11 may be estimated using the indoor air temperature (room temperature) and the outdoor air temperature (outdoor temperature). More specifically, the probability of occurrence of problems with the compressor 11 may be estimated based on the room temperature DA, the ambient temperature DOA, and the difference in temperature between the room temperature DA and the ambient temperature DOA.
- a temperature condition under which the probability of occurrence of problems with the compressor 11 is low when starting the heating operation, and a temperature condition under which the probability of occurrence of problems with the compressor 11 is low when starting the cooling operation are found through tests conducted by the inventors of the present application.
- the first protection control is executed as the compressor protection control, so that problems with the compressor 11 are more assuredly avoided.
- Fig. 4 is an example of results of tests conducted by the inventors of the present application to determine whether problems with the compressor 11 occur when the second protection control of the compressor protection control is executed at the time of starting the heating operation, with changes in the room temperature DA, the ambient temperature DOA, and the difference in temperature between the room temperature DA and the ambient temperature DOA.
- the vertical axis indicates the room temperature DA
- the horizontal axis indicates the ambient temperature DOA.
- diagonal lines indicate indoor-outdoor temperature differences, that is, differences (DA-DOA) in temperature between the room temperature DA and the ambient temperature DOA.
- DA-DOA differences
- the shaded section indicates an example of a temperature region (hereafter, referred to as "temperature region RL") in which when starting the heating operation, the probability of occurrence of problems with the compressor 11 is low and the need for increasing the heating performance is high.
- the temperature region RL is surrounded by conditions of the room temperature DA being less than or equal to 20°C, the ambient temperature DOA being greater than or equal to 0°C, and the indoor-outdoor temperature difference being less than or equal to X5.
- An example of the indoor-outdoor temperature difference X5 is 10°C.
- the second protection control of the compressor protection control is executed at the time of starting the heating operation, the probability of occurrence of problems with the compressor 11 is low.
- the ambient temperature DOA is less than 0°C or the indoor-outdoor temperature difference is greater than 10°C, if the second protection control of the compressor protection control is executed at the time of starting the heating operation, the probability of occurrence of problems with the compressor 11 is high.
- the second protection control of the compressor protection control is executed at the time of starting the heating operation, the probability of occurrence of problems with the compressor 11 is low. However, the heating performance does not need to be increased.
- the inventors of the present application conducted tests to determine whether problems with the compressor 11 occur when the second protection control of the compressor protection control is executed at the time of starting the cooling operation, with changes in the room temperature DA, the ambient temperature DOA, and the difference in temperature between the room temperature DA and the ambient temperature DOA. Temperature conditions under which when starting the cooling or heating operation, the probability of occurrence of problems with the compressor 11 is low, and the need for increasing the cooling or heating performance is high are determined based on these tests and described below. Such temperature conditions of the cooling or heating operation are stored in the control unit 50, for example, as a map MP1 shown in Fig. 5 for the heating operation and a map MP2 shown in Fig. 6 for the cooling operation.
- the room temperature DA is less than or equal to a first determination temperature DAX1 (room temperature threshold value) (DA ⁇ DAX1).
- the ambient temperature DOA is in a first temperature range (DOAL1 ⁇ DOA ⁇ DOAH1).
- DOAL1 denotes the lower limit value of the first temperature range
- DOAH1 denotes the upper limit value of the first temperature range.
- the difference in temperature between the room temperature DA and the ambient temperature DOA is less than or equal to a first determination temperature difference DDX1 (temperature difference threshold value) (DA-DOA ⁇ DDX).
- the first determination temperature DAX1 is a determination value of the room temperature that determines whether the heating performance needs to be increased.
- An example of the first determination temperature DAX1 is 13°C.
- the lower limit value DOAL1 of the first temperature range is a determination value of the ambient temperature that determines whether the probability of occurrence of problems with the compressor 11 is low when starting the heating operation.
- An example of the lower limit value DOAL1 is 0°C.
- the upper limit value DOAH1 of the first temperature range is a determination value of the ambient temperature that determines whether the heating performance needs to be increased.
- An example of the upper limit value DOAH1 is 24°C.
- the first determination temperature difference DDX1 is a determination value of the indoor-outdoor temperature difference that determines whether the probability of occurrence of problems with the compressor 11 is low when starting the heating operation.
- An example of the first determination temperature difference DDX1 is 10°C.
- the room temperature DA is greater than or equal to a second determination temperature DAX2 (room temperature threshold value) (DA ⁇ DAX2).
- the ambient temperature DOA is in a second temperature range (DOAL2 ⁇ DOA ⁇ DOAH2).
- DOAL2 denotes the lower limit value of the second temperature range
- DOAH2 denotes the upper limit value of the second temperature range.
- the difference in temperature between the room temperature DA and the ambient temperature DOA is less than or equal to a second determination temperature difference DDX2 (temperature difference threshold value) (DA-DOA ⁇ DDX2).
- the second determination temperature DAX2 is a determination value of the room temperature that determines whether the cooling performance needs to be increased.
- An example of the second determination temperature DAX2 is 25°C.
- the lower limit value DOAL2 of the second temperature range is a determination value of the ambient temperature that determines whether the cooling performance needs to be increased.
- An example of the lower limit value DOAL2 is 25°C.
- the upper limit value DOAH2 of the second temperature range is a determination value of the ambient temperature that determines whether the probability of occurrence of problems with the compressor 11 is low when starting the cooling operation.
- An example of the upper limit value DOAH2 is 45°C.
- the second determination temperature difference DDX2 is a determination value of the indoor-outdoor temperature difference that determines whether the probability of occurrence of problems with the compressor 11 is low when starting the cooling operation.
- An example of the second determination temperature difference DDX2 is -10°C.
- the control unit 50 uses the map MP1 to select the first protection control and the second protection control when starting the heating operation based on the temperature conditions a1, a2, and a3 of the heating operation.
- the control unit 50 uses the map MP2 to select the first protection control and the second protection control when starting the cooling operation based on the temperature conditions b1, b2, and b3 of the cooling operation.
- the vertical axis indicates the room temperature DA
- the horizontal axis indicates the ambient temperature DOA.
- the diagonal line indicates a boundary condition of the indoor-outdoor temperature difference.
- the shading indicates a temperature region R1 in which all of the temperature conditions a1, a2, and a3 are satisfied. More specifically, the second protection control is selected in the temperature region R1, and the first protection control is selected in a region excluding the temperature region R1.
- the temperature region R1 of the map MP1 may be the same as the temperature region RL shown in Fig. 4 . More specifically, in the temperature conditions a1, a2, and a3 of the heating operation, the first determination temperature DAX1 may be 20°C, the lower limit value DOAL1 of the first temperature range may be 0°C, the upper limit value DOAH1 may be 30°C, and the first determination temperature difference DDX1 may be 10°C.
- the vertical axis indicates the room temperature DA
- the horizontal axis indicates the ambient temperature DOA.
- the diagonal line indicates a boundary condition of the indoor-outdoor temperature difference.
- the shading indicates a temperature region R2 in which all of the temperature conditions b1, b2, and b3 are satisfied. More specifically, the second protection control is selected in the temperature region R2, and the first protection control is selected in a region excluding the temperature region R2.
- control unit 50 uses the map MP1 to select one of the first protection control and the second protection control when starting the heating operation, and uses the map MP2 to select one of the first protection control and the second protection control when starting the cooling operation.
- step S11 the control unit 50 determines whether the heating operation is instructed to be performed. The determination of step S11 is made, for example, based on whether the control unit 50 receives an instruction to perform the heating operation from the remote controller 51.
- step S11 the control unit 50 selects the map MP1 in step S12.
- step S13 the control unit 50 determines whether the coordinates specified by the room temperature DA and the ambient temperature DOA are in the range of the temperature region R1 in the map MP1.
- step S13: YES When determining that the coordinates specified by the room temperature DA and the ambient temperature DOA are in the range of the temperature region R1 (step S13: YES), that is, when determining that all of the temperature conditions a1 to a3 are satisfied, the control unit 50 selects the second protection control in step S14.
- step S13: NO When determining that the coordinates specified by the room temperature DA and the ambient temperature DOA are outside the range of the temperature region R1 (step S13: NO), that is, when determining that at least one of the temperature conditions a1 to a3 is not satisfied, the control unit 50 selects the first protection control in step S15.
- step S11 When determining in step S11 that the heating operation is not instructed to be performed (step S11: NO), the control unit 50 determines in step S16 whether the cooling operation is instructed to be performed. The determination of step S16 is made, for example, based on whether the control unit 50 receives an instruction to perform the cooling operation from the remote controller 51. When determining in step S16 that the cooling operation is instructed to be performed (step S16: YES), the control unit 50 selects the map MP2 in step S17. In step S18, the control unit 50 determines whether the coordinates specified by the room temperature DA and the ambient temperature DOA are in the range of the temperature region R2 in the map MP2.
- step S18: YES When determining that the coordinates specified by the room temperature DA and the ambient temperature DOA are in the range of the temperature region R2 (step S18: YES), that is, when determining that all of the temperature conditions b1 to b3 are satisfied, the control unit 50 proceeds to step S14. That is, the control unit 50 selects the second protection control.
- step S18: NO When determining that the coordinates specified by the room temperature DA and the ambient temperature DOA are outside the range of the temperature region R2 (step S18: NO), that is, when determining that at least one of the temperature conditions b1 to b3 is not satisfied, the control unit 50 selects the first protection control in step S19.
- step S16 When determining in step S16 that the cooling operation is not instructed to be performed, the control unit 50 terminates the first activation control.
- a dehumidifying operation is an example of an operation other than the heating operation and the cooling operation.
- the present embodiment has the following advantages.
- FIG. 1 A second embodiment of an air conditioner 1 will now be described with reference to Figs. 1 and 8 .
- the air conditioner 1 of the present embodiment differs from the air conditioner 1 of the first embodiment in the first activation control.
- components of the air conditioner 1 refer to the components of the air conditioner 1 shown in Fig. 1 .
- the refrigerant may condense and accumulate at a side corresponding to the lower one of the indoor air temperature and the outdoor air temperature.
- a stagnation phenomenon is generated, that is, the liquid refrigerant dissolves and accumulates in the lubricant oil of the compressor 11 or the liquid refrigerant accumulates in the outdoor heat exchanger 13.
- the stagnation phenomenon is generated and the compressor 11 is activated in the heating operation, if the increase rate of the operating frequency of the compressor 11 is increased, generation of oil foaming in the compressor 11 is facilitated. This causes a failure of the compressor 11.
- the stagnation phenomenon is generated and the compressor 11 is activated in the cooling operation, if the increase rate of the operating frequency of the compressor 11 is increased, generation of oil foaming in the compressor 11 is facilitated in the same manner as in the heating operation.
- the control unit 50 executes a refrigerant discharge activation operation to avoid a failure of the compressor 11 caused by the stagnation phenomenon when starting the cooling or heating operation.
- the control unit 50 operates the compressor 11 with the four-way switching valve 12 switched to the reverse cycle (cooling mode connection state) for a predetermined time (e.g., one minute). This allows the liquid refrigerant accumulated in the outdoor heat exchanger 13 to flow to the indoor heat exchanger 21.
- the liquid refrigerant in the indoor heat exchanger 21 is evaporated by the indoor heat exchanger 21 and becomes gas refrigerant.
- the gas refrigerant is drawn into the compressor 11. This limits generation of oil foaming in the compressor 11.
- the control unit 50 operates the compressor 11 with the four-way switching valve 12 switched to the reverse cycle (heating mode connection state) for a predetermined time (e.g., one minute). This allows the liquid refrigerant accumulated in the indoor heat exchanger 21 to flow to the outdoor heat exchanger 13.
- the liquid refrigerant in the outdoor heat exchanger 13 is evaporated by the outdoor heat exchanger 13 and becomes gas refrigerant.
- the gas refrigerant is drawn into the compressor 11. This limits generation of oil foaming in the compressor 11.
- the probability of occurrence of problems with the compressor 11 is lowered.
- the control unit 50 executes a second activation control that selects the second protection control after the refrigerant discharge activation operation.
- the procedures of the second activation control will now be described with reference to Fig. 8 .
- step S21 the control unit 50 determines whether the refrigerant discharge activation operation is performed.
- step S21: YES determines in step S22 whether the refrigerant discharge activation operation is completed.
- step S22: YES determines in step S22 whether the refrigerant discharge activation operation is completed.
- step S22: NO determines in step S22 that the refrigerant discharge activation operation is not completed.
- step S21 When determining in step S21 that the refrigerant discharge activation operation is not performed (step S21: NO), the control unit 50 proceeds to the first activation control in step S24.
- the control unit 50 selects one of the first protection control and the second protection control based on the first activation control.
- the present embodiment has the following advantages. (2-1) When the refrigerant discharge activation operation is performed, the control unit 50 executes the second protection control. When the refrigerant discharge activation operation has been completed, the probability of occurrence of problems with the compressor 11 is lowered. Execution of the second protection control after the refrigerant discharge activation operation allows the operating frequency of the compressor 11 to reach the necessary operating frequency FN quickly after the refrigerant discharge activation operation. Thus, the cooling or heating operation starts up quickly.
- the description related to the above embodiments exemplifies, without any intention to limit, applicable forms of an air conditioner according to the present disclosure.
- the air conditioner according to present disclosure is applicable to, for example, modified examples of the above embodiment that are described below and combinations of at least two of the modified examples that do not contradict each other.
- the control executed on the compressor 11 to increase the operating frequency of the compressor 11 to the necessary operating frequency FN in the second protection control may be changed in any manner. More specifically, the control may be changed in any manner on condition that the time for the operating frequency of the compressor 11 to reach the necessary operating frequency FN in the second protection control is shorter than the time for the operating frequency of the compressor 11 to reach the necessary operating frequency FN in the first protection control.
- the second protection control may be changed, for example, as described below in (A) to (F).
- the first target frequency FA1 and the second target frequency FA2 may be changed in any manner. For example, the first target frequency FA1 and the second target frequency FX2 may have different values.
- the value of the first target frequency FA1 may be greater than the value of the second target frequency FX2 and less than the value of the third target frequency FX3.
- the second target frequency FA2 may be equal to the fourth target frequency FX4.
- the first period TA1 and the second period TA2, during which the compressor 11 respectively maintains the first target frequency FA1 and the second target frequency FA2 may be longer than or equal to the first to fourth periods TX1 to TX4 of the first protection control.
- the first period TA1 and the second period TA2, during which the compressor 11 respectively maintains the first target frequency FA1 and the second target frequency FA2, may be changed in any manner.
- the first period TA1 may differ from the second period TA2.
- the first period TA1 and the second period TA2 may be separately set.
- the number of target frequencies in the second protection control is not limited to two and may be changed in any manner. That is, the number of target frequencies in the second protection control may be one or three or greater.
- the modifications (A) to (D) may be combined with one another.
- the operating frequency of the compressor 11 may be set to the necessary operating frequency FN. That is, the target frequencies such as the first target frequency FA1 may be omitted.
- the control executed on the compressor 11 to increase the operating frequency of the compressor 11 to the necessary operating frequency FN in the first protection control may be changed, for example, as follows.
- Each of the first to fourth target frequencies FX1 to FX4 may be changed in any manner.
- the difference between the second target frequency FX2 and the first target frequency FX1 may differ from the difference between the third target frequency FX3 and the second target frequency FX2.
- the difference between the fourth target frequency FX4 and the third target frequency FX3 may differ from the difference between the third target frequency FX3 and the second target frequency FX2.
- the first to fourth periods TX1 to TX4, during which the compressor 11 respectively maintains the first to fourth target frequencies FX1 to FX4 may be changed in any manner.
- some of the first to fourth periods TX1 to TX4 may differ from the rest of the first to fourth periods TX1 to TX4.
- the number of target frequencies in the first protection control is not limited to four and may be changed in any manner. That is, the number of target frequencies in the first protection control may be three or five or greater.
- the temperature DF of the discharge pipe of the compressor 11 and the ambient temperature DOA may be added to the conditions for selecting the first protection control and the second protection control.
- the temperature DF of the discharge pipe is greater than or equal to a temperature threshold value DFX (DF ⁇ DFX).
- the ambient temperature DOA is greater than or equal to a determination temperature threshold value DOAY (DOA ⁇ DOAY).
- DOA ⁇ DOAY determination temperature threshold value
- the difference in temperature between the temperature DF of the discharge pipe and the ambient temperature DOA is greater than or equal to the temperature difference threshold value DDY (DF-DOA ⁇ DDY).
- the temperature threshold value DFX is a threshold value that limits the condition for proceeding to the maps MP1 and MP2 and is set in advance through tests or the like.
- An example of the temperature threshold value DFX is -3°C.
- the determination temperature threshold value DOAY is a determination value that limits the condition for proceeding to the maps MP1 and MP2 and is set in advance through tests or the like.
- An example of the determination temperature threshold value DOAY is -15°C.
- the temperature difference threshold value DDY is a threshold value that limits the condition for proceeding to the maps MP1 and MP2 and is set in advance through tests or the like.
- the control unit 50 stores a map MP3 specifying the relationship between the temperature DF of the discharge pipe of the compressor 11 and the ambient temperature DOA to select the first protection control and the second protection control.
- Fig. 9 shows an example of the map MP3.
- the vertical axis indicates the temperature DF of the discharge pipe of the compressor 11, and the horizontal axis indicates the ambient temperature DOA.
- the diagonal line indicates the boundary condition of the difference in temperature between the temperature DF of the discharge pipe and the ambient temperature DOA.
- the unshaded region indicates a temperature region R3 in which all of temperature conditions c1, c2, and c3 are satisfied.
- the control unit 50 determines whether the temperature DF of the discharge pipe and the ambient temperature DOA are in the temperature region R3. More specifically, the control unit 50 determines whether the temperature DF of the discharge pipe of the compressor 11 and the ambient temperature DOA are in the temperature region R3. When determining that the temperatures are in the temperature region R3, that is, when determining that the temperature conditions c1, c2, and c3 are satisfied, the control unit 50 uses the map MP1 when starting the heating operation to select one of the first protection control and the second protection control, and uses the map MP2 when starting the cooling operation to select one of the first protection control and the second protection control.
- the control unit 50 executes the first protection control. As described above, when the relationship between the temperature DF of the discharge pipe of the compressor 11 and the ambient temperature DOA is added to the conditions for executing the second protection control, the second protection control is executed more appropriately in the cooling or heating operation.
- a third protection control that differs from the first protection control and the second protection control may be executed as the compressor protection control.
- the control unit 50 controls the compressor 11 so that the time for the operating frequency of the compressor 11 to reach the necessary operating frequency FN is longer than the time (the period TX) for the operating frequency of the compressor 11 to reach the necessary operating frequency FN in the first protection control.
- the ambient temperature DOA is greater than or equal to the determination temperature threshold value DOAY and less than a determination temperature threshold value DOAZ that is greater than the determination temperature threshold value DOAY (DOAZ>DOAY), and the temperature DF of the discharge pipe of the compressor 11 is less than the temperature threshold value DFX.
- a fourth protection control that differs from the first protection control and the second protection control may be executed as the compressor protection control.
- the control unit 50 controls the compressor 11 so that the time for the operating frequency of the compressor 11 to reach the necessary operating frequency FN is longer than the time (the period TX) for the operating frequency of the compressor 11 to reach the necessary operating frequency FN in the first protection control and is shorter than the time for the operating frequency of the compressor 11 to reach the necessary operating frequency FN in the third protection control.
- the ambient temperature DOA is greater than or equal to the determination temperature threshold value DOAZ, and the difference in temperature between the temperature DF of the discharge pipe and the ambient temperature DOA is less than the temperature difference threshold value DDY.
- a fifth protection control that differs from the first protection control and the second protection control may be executed as the compressor protection control.
- the control unit 50 controls the compressor 11 so that the time for the operating frequency of the compressor 11 to reach the necessary operating frequency FN is longer than the time (the period TX) for the operating frequency of the compressor 11 to reach the necessary operating frequency FN in the first protection control and is shorter than the time for the operating frequency of the compressor 11 to reach the necessary operating frequency FN in the fourth protection control.
- At least one of the temperature condition a1 of the heating operation or the temperature condition b1 of the cooling operation may be omitted from the first activation control.
- one of the outdoor controller 16 and the indoor controller 23 may be omitted.
- the indoor temperature sensor 52 is connected to the outdoor controller 16 by wire or through wireless communication.
- the indoor fan 22 is connected to the outdoor controller 16 by wire.
- the outdoor controller 16 corresponds to the control unit.
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Abstract
Description
- The present disclosure relates to an air conditioner.
- When starting a cooling or heating operation, a typical air conditioner performs an activation operation that lowers the operating frequency of a compressor for a predetermined time from when the compressor is activated in order to prevent backflow of liquid to the compressor (for example, refer to Patent Document 1).
- Patent Document 1: Japanese Laid-Open Patent Publication No.
6-341720 - However, when starting the cooling or heating operation, the liquid backflow to the compressor does not always occur. More specifically, the probability of occurrence of the liquid backflow to the compressor may be low depending on the surrounding environment of the compressor at a time of starting the cooling or heating operation. When the activation operation that lowers the operating frequency of the compressor is performed even in such a case, the time from when the compressor is activated to when the room temperature reaches the set temperature extends. This hinders a quick startup of the cooling or heating operation.
- It is an objective of the present disclosure to provide an air conditioner that starts up the cooling or heating operation quickly.
- To achieve the above objective, an air conditioner includes a compressor in which an operating frequency is changeable and a control unit that executes a compressor protection control. The compressor protection control increases the operating frequency of the compressor to a necessary operating frequency when starting a cooling operation or a heating operation. The compressor protection control includes a first protection control and a second protection control. The first protection control controls the operating frequency so that a time from when the compressor is activated to when the operating frequency reaches the necessary operating frequency is relatively long. The second protection control controls the operating frequency so that the time from when the compressor is activated to when the operating frequency reaches the necessary operating frequency is relatively short. When executing the compressor protection control, if a predetermined condition is satisfied, the control unit executes the second protection control.
- In this configuration, if the predetermined condition is satisfied when executing the compressor protection control, the second protection control is executed. This shortens the time from when the
compressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN. As a result, the time from when the cooling or heating operation is started to when the room temperature DA reaches the set temperature is shortened, and the cooling or heating operation starts up quickly. - The predetermined condition refers to a condition that lowers the probability of occurrence of problems with the compressor caused by sudden increases in the operating frequency of the compressor when activated, such as a rise in the degree of dilution caused by a lowered surface of oil in the compressor or a returned refrigerant, backflow of liquid to the compressor, freezing of the outdoor heat exchanger and the indoor heat exchanger used as evaporators, and negative pressure of the suction side of the compressor.
- Preferably, the control unit sets a first target frequency and a second target frequency in the compressor protection control. The second target frequency is greater than the first target frequency and is less than the necessary operating frequency. The control unit maintains the operating frequency at the first target frequency for a first period and at the second target frequency for a second period so that the operating frequency is increased in a stepped manner. The first target frequency of the second protection control is greater than the first target frequency of the first protection control. The second target frequency of the second protection control is greater than the second target frequency of the first protection control.
- In this configuration, the second protection control shortens the time from when the compressor is activated to when the operating frequency of the compressor reaches the necessary operating frequency. Thus, the cooling or heating operation starts up quickly.
- Preferably, the control unit sets a first target frequency and a second target frequency in the compressor protection control. The second target frequency is greater than the first target frequency and is less than the necessary operating frequency. The control unit maintains the operating frequency at the first target frequency for a first period and at the second target frequency for a second period so that the operating frequency is increased in a stepped manner. The first period of the second protection control is shorter than the first period of the first protection control. The second period of the second protection control is shorter than the second period of the second protection control.
- In this configuration, the second protection control shortens the time from when the compressor is activated to when the operating frequency of the compressor reaches the necessary operating frequency. Thus, the cooling or heating operation starts up quickly.
- Preferably, the predetermined condition in the heating operation differs from the predetermined condition in the cooling operation.
- In this configuration, the second protection control is appropriately executed in the cooling or heating operation.
- Preferably, the predetermined condition includes an indoor air temperature, an outdoor air temperature, and a temperature difference between the indoor air temperature and the outdoor air temperature.
- Preferably, the predetermined condition in the heating operation is that the indoor air temperature is less than or equal to a room temperature threshold value, that the outdoor air temperature is greater than or equal to an outdoor temperature threshold value, and that the temperature difference between the indoor air temperature and the outdoor air temperature is less than or equal to a temperature difference threshold value.
- In this configuration, the indoor air temperature and the outdoor air temperature, which are easily obtained information about the air conditioner, are used to set the condition that limits occurrence of problems with the compressor such as backflow of liquid to the compressor in the compressor protection control.
- Preferably, the predetermined condition includes a temperature of a discharge pipe of the compressor and an outdoor air temperature.
- In this configuration, the second protection control is more appropriately executed in the cooling or heating operation.
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Fig. 1 is a conceptual diagram showing a first embodiment of an air conditioner. -
Fig. 2 is a block diagram showing the electrical configuration of the air conditioner. -
Fig. 3 is a graph showing changes in the operating frequency of a compressor in a compressor protection control. -
Fig. 4 is a graph showing the relationship among a room temperature, an ambient temperature, a difference in temperature between the room temperature and the ambient temperature, and the probability of problems with the compressor. -
Fig. 5 is a map used to select a first protection control and a second protection control in the heating operation. -
Fig. 6 is a map used to select the first protection control and the second protection control in the cooling operation. -
Fig. 7 is a flowchart showing the procedures of a first activation control executed by the air conditioner. -
Fig. 8 is a flowchart showing the procedures of a second activation control executed by a second embodiment of an air conditioner. -
Fig. 9 is a map showing the relationship between the ambient temperature and the temperature of a discharge pipe of a compressor in a modified example of an air conditioner. - An
air conditioner 1 will now be described with reference to the drawings. - As shown in
Fig. 1 , theair conditioner 1 includes arefrigerant circuit 40. Therefrigerant circuit 40 includes arefrigerant pipe 30 that circulates a refrigerant between anoutdoor unit 10 and anindoor unit 20. Theair conditioner 1 of the present embodiment includes therefrigerant circuit 40 formed by connecting therefrigerant pipe 30 to theoutdoor unit 10, which is installed outdoors, and theindoor unit 20, which is a wall-installation type and is installed on an indoor wall surface or the like. - The
outdoor unit 10 includes, for example, acompressor 11 in which the operating frequency is changeable, a four-way switching valve 12, anoutdoor heat exchanger 13, anexpansion valve 14, anoutdoor fan 15, and anoutdoor controller 16. Theoutdoor fan 15 includes amotor 15a and animpeller 15b connected to the output shaft of themotor 15a. Themotor 15a is a drive source having a changeable rotational speed. An example of theimpeller 15b is a propeller fan. - The
compressor 11 is, for example, a rocking piston compressor and includes, for example, a compression mechanism, a motor, and a crankshaft that transmits driving power of the motor to the compression mechanism (none shown). Thecompressor 11 includes anaccumulator 11a that separates the refrigerant into gas and liquid. An example of the motor is a three-phase brushless motor. Theexpansion valve 14 is, for example, an electronic expansion valve. Theoutdoor fan 15 rotates theimpeller 15b using themotor 15a to facilitate heat exchange between the outdoor air and the refrigerant flowing through a heat transfer tube of theoutdoor heat exchanger 13. Thus, theoutdoor fan 15 generates a flow of outdoor air that passes through theoutdoor heat exchanger 13. Theoutdoor controller 16 is electrically connected to the motor of thecompressor 11, the four-way switching valve 12, theexpansion valve 14, and themotor 15a of theoutdoor fan 15. - The
indoor unit 20 includes, for example, anindoor heat exchanger 21, anindoor fan 22, and anindoor controller 23. Theindoor fan 22 includes amotor 22a and an impeller (not shown) connected to the output shaft of themotor 22a. Themotor 22a is a drive source having a changeable rotational speed. An example of the impeller is a crossflow fan. Theindoor fan 22 rotates the impeller using themotor 22a to facilitate heat exchange between the indoor air and the refrigerant flowing through a heat transfer tube of theindoor heat exchanger 21. Thus, theindoor fan 22 generates a flow of indoor air that passes through theindoor heat exchanger 21. Theindoor controller 23 is electrically connected to themotor 22a of theindoor fan 22. Theindoor controller 23 is, for example, configured to perform wireless communication with a remote controller 51 (refer toFig. 2 ) of theair conditioner 1 using infrared light or the like. Theindoor controller 23 is configured to perform wired communication with theoutdoor controller 16 through a signal line. Theindoor controller 23 controls theindoor unit 20, and theoutdoor controller 16 controls theoutdoor unit 10 based on an operating instruction of theremote controller 51. - The
refrigerant circuit 40 is configured by connecting thecompressor 11, the four-way switching valve 12, theoutdoor heat exchanger 13, theexpansion valve 14, and theindoor heat exchanger 21 with therefrigerant pipe 30 as a loop. Therefrigerant circuit 40 is configured to execute a vapor compression refrigeration cycle that reversibly circulates the refrigerant by switching the four-way switching valve 12. - More specifically, when the four-
way switching valve 12 is switched to a cooling mode connection state (illustrated with solid lines), therefrigerant circuit 40 forms a cooling cycle in which the refrigerant circulates in the order of thecompressor 11, the four-way switching valve 12, theoutdoor heat exchanger 13, theexpansion valve 14, theindoor heat exchanger 21, the four-way switching valve 12, and thecompressor 11. As a result, theair conditioner 1 performs the cooling operation in which theoutdoor heat exchanger 13 acts as a condenser and theindoor heat exchanger 21 acts as an evaporator. When the four-way switching valve 12 is switched to a heating mode connection state (illustrated with broken lines), therefrigerant circuit 40 forms a heating cycle in which the refrigerant circulates in the order of thecompressor 11, the four-way switching valve 12, theindoor heat exchanger 21, theexpansion valve 14, theoutdoor heat exchanger 13, the four-way switching valve 12, and thecompressor 11. As a result, theair conditioner 1 performs the heating operation in which theindoor heat exchanger 21 acts as a condenser and theoutdoor heat exchanger 13 acts as an evaporator. - As shown in
Fig. 2 , acontrol unit 50 that controls theair conditioner 1 includes theoutdoor controller 16 and theindoor controller 23. Each of theoutdoor controller 16 and theindoor controller 23 includes, for example, a storage device and an arithmetic processing device that executes a predetermined control program. The arithmetic processing device includes, for example, a central processing unit (CPU) or a micro processing unit (MPU). The storage unit stores various control programs and information used for various control processes. The storage device includes, for example, a nonvolatile memory and a volatile memory. - The
control unit 50 is connected to theremote controller 51, anindoor temperature sensor 52, anoutdoor temperature sensor 53, and a discharge pipe temperature sensor 54 so that communication is performed. - More specifically, the
control unit 50 is configured to perform wireless communication with the remote controller 51 (refer toFig. 3 ) using, for example, infrared light. More specifically, theremote controller 51 transmits signals of an operating instruction (instruction to perform cooling operation, heating operation, etc.) and a deactivating instruction to thecontrol unit 50. Theindoor temperature sensor 52, theoutdoor temperature sensor 53, and the discharge pipe temperature sensor 54 are electrically connected to thecontrol unit 50. Theindoor temperature sensor 52 is used to measure the indoor air temperature (room temperature) and is disposed, for example, in the vicinity of an inlet of theindoor unit 20. Theindoor temperature sensor 52 transmits a signal corresponding to the room temperature to thecontrol unit 50. Theoutdoor temperature sensor 53 is used to measure the outdoor air temperature (outdoor temperature) and is disposed, for example, in the vicinity of an inlet of theoutdoor unit 10. Theoutdoor temperature sensor 53 transmits a signal corresponding to the outdoor temperature to thecontrol unit 50. The discharge pipe temperature sensor 54 is used to measure the temperature of a discharge pipe of thecompressor 11, that is, the temperature of a discharged gas refrigerant discharged from thecompressor 11. The discharge pipe temperature sensor 54 is attached to the discharge pipe of thecompressor 11. The discharge pipe temperature sensor 54 transmits a signal corresponding to the temperature of the gas refrigerant discharged from thecompressor 11 to thecontrol unit 50. As described above, thecontrol unit 50 receives various signals (operating instruction and measurement information) from theremote controller 51, theindoor temperature sensor 52, theoutdoor temperature sensor 53, and the discharge pipe temperature sensor 54. Thecontrol unit 50 obtains the room temperature (hereafter, referred to as "room temperature DA") based on measurement information of theindoor temperature sensor 52, obtains the outdoor temperature (hereafter, referred to as "ambient temperature DOA") based on measurement information of theoutdoor temperature sensor 53, and obtains a temperature DF of the discharge pipe of the compressor 11 (temperature of discharged gas refrigerant) based on measurement information of the discharge pipe temperature sensor 54. - Since the
indoor controller 23 is electrically connected to theoutdoor controller 16, the operating instruction and the room temperature DA, which are received by theindoor controller 23, may be transmitted to theoutdoor controller 16. Also, the ambient temperature DOA and the temperature DF of the discharge pipe of thecompressor 11, which are received by theoutdoor controller 16, may be transmitted to theindoor controller 23. - The
indoor controller 23 controls the rotational speed of themotor 22a of theindoor fan 22 based on an operating instruction of theremote controller 51 and measurement information. - The
outdoor controller 16 controls the operating frequency of thecompressor 11, the switching of the four-way switching valve 12 between the cooling mode connection state and the heating mode connection state, the opening degree of theexpansion valve 14, and the rotational speed of themotor 15a of theoutdoor fan 15 based on an operating instruction of theremote controller 51 and measurement information. - The
control unit 50 executes the cooling operation and the heating operation through theindoor controller 23 and theoutdoor controller 16 based on an operating instruction of theremote controller 51 and measurement information. In the cooling operation and the heating operation, thecontrol unit 50 controls thecompressor 11, theexpansion valve 14, theoutdoor fan 15, and theindoor fan 22 so that the indoor temperature reaches the temperature set by theremote controller 51. - In the cooling operation and the heating operation, the
control unit 50 sets an increase rate at which the operating frequency of thecompressor 11 is increased and a decrease rate at which the operating frequency is decreased so that the increase rate is equal to the decrease rate. An example of the increase rate and the decrease rate, which are change rates of the operating frequency of thecompressor 11 in the cooling operation and the heating operation, is 2 Hz per second. - In addition, when activating the
compressor 11 to start the cooling or heating operation, thecontrol unit 50 increases the low operating frequency of thecompressor 11 to an operating frequency necessary for the cooling or heating operation (hereafter, referred to as "necessary operating frequency FN"). In this case, thecontrol unit 50 executes a compressor protection control when activating thecompressor 11. In the compressor protection control, in order to prevent problems with thecompressor 11, the operating frequency of thecompressor 11 is low at the beginning and is increased in a stepped manner as time elapses to the necessary operating frequency FN, at which thecompressor 11 stably operates. Examples of problems with thecompressor 11 caused by sudden increases in the operating frequency of thecompressor 11 when activated include a rise in the degree of dilution caused by a lowered surface of oil in thecompressor 11 or a returned refrigerant, backflow of liquid to thecompressor 11, freezing of theoutdoor heat exchanger 13 and theindoor heat exchanger 21 used as evaporators, and negative pressure of the suction side of thecompressor 11. - Graph GX indicated by the broken line in
Fig. 3 is a schematic graph showing a typical compressor protection control. - As indicated by graph GX in
Fig. 3 , in the compressor protection control, the operating frequency of thecompressor 11 is changed so that the operating frequency is maintained at multistage target frequencies for a predetermined time before reaching the necessary operating frequency FN. More specifically, in the compressor protection control, thecontrol unit 50 stores a first target frequency FX1, a second target frequency FX2 that is greater than the first target frequency FX1, a third target frequency FX3 that is greater than the second target frequency FX2, and a fourth target frequency FX4 that is greater than the third target frequency FX3. At time t1, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 reaches the first target frequency FX1. From time t1 to time t3, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 is maintained at the first target frequency FX1. At time t3, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 changes from the first target frequency FX1 to the second target frequency FX2. From time t3 to time t5, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 is maintained at the second target frequency FX2. At time t5, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 changes from the second target frequency FX2 to the third target frequency FX3. From time t5 to time t6, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 is maintained at the third target frequency FX3. At time t6, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 changes from the third target frequency FX3 to the fourth target frequency FX4. From time t6 to time t7, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 is maintained at the fourth target frequency FX4. At time t7, thecontrol unit 50 drives the compressor so that the operating frequency of thecompressor 11 changes from the fourth target frequency FX4 to the necessary operating frequency FN. - In graph GX shown in
Fig. 3 , the difference (FX2-FX1) between the second target frequency FX2 and the first target frequency FX1, the difference (FX3-FX2) between the third target frequency FX3 and the second target frequency FX2, and the difference (FX4-FX3) between the fourth target frequency FX4 and the third target frequency FX3 are equal to each other. In addition, a first period TX1 during which the operating frequency of thecompressor 11 is maintained at the first target frequency FX1, a second period TX2 during which the second target frequency FX2 is maintained, and a third period TX3 during which the third target frequency FX3 is maintained, and a fourth period TX4 during which the fourth target frequency FX4 is maintained are equal to each other. - When starting the cooling or heating operation, if the compressor protection control is executed, problems with the
compressor 11 are avoided. However, since the operating frequency of thecompressor 11 is gradually increased as indicated by graph GX shown inFig. 3 , the time from when the user issues an instruction to perform the cooling or heating operation using theremote controller 51 to when the indoor air temperature reaches the set temperature extends. That is, when starting the cooling or heating operation, the startup of the cooling or heating operation is impeded. As a result, the cooling performance or the heating performance is lowered when starting the cooling or heating operation. - The probability of occurrence of problems with the
compressor 11 may be low depending on the surrounding environment (outdoor air temperature and indoor air temperature) of thecompressor 11. When the probability of occurrence of problems with thecompressor 11 is low, if the compressor protection control indicated by graph GX shown inFig. 3 is executed, thecompressor 11 is operated with a low cooling performance or a low heating performance even though problems with thecompressor 11 is not likely to occur. - In this regard, in the present embodiment, the
control unit 50 executes a first activation control that changes the mode of the compressor protection control based on whether the probability of occurrence of problems with thecompressor 11 is high or low. More specifically, when the probability of occurrence of problems with thecompressor 11 is high, thecontrol unit 50 executes a first protection control, that is, the compressor protection control indicated by graph GX shown inFig. 3 . When the probability of occurrence of problems with thecompressor 11 is low, thecontrol unit 50 executes a second protection control. The second protection control increases the operating frequency of thecompressor 11 to the necessary operating frequency FN more quickly than the compressor protection control (first protection control) indicated by graph GX shown inFig. 3 . - The second protection control will now be described in detail.
- The second protection control has a first target frequency FA1 and a second target frequency FA2. That is, the number of target frequencies of the second protection control is less than the number of target frequencies of the first protection control. The first target frequency FA1 is greater than the first target frequency FX1 of the first protection control. In the present embodiment, the first target frequency FA1 is equal to the second target frequency FX2 of graph GX. The second target frequency FA2 is greater than the second target frequency FX2 of the first protection control. In the present embodiment, the second target frequency FA2 is greater than the fourth target frequency FX4 of graph GX and is less than the necessary operating frequency FN. The first target frequency FA1 is equal to the difference (FA2-FA1) between the second target frequency FA2 and the first target frequency FA1. The difference (FA2-FA1) between the second target frequency FA2 and the first target frequency FA1 is greater than the difference (FN-FA2) between the necessary operating frequency FN and the second target frequency FA2. A first period TA1 during which the operating frequency of the
compressor 11 is maintained at the first target frequency FA1 is equal to a second period TA2 during which the operating frequency of thecompressor 11 is maintained at the second target frequency FA2. - In the second protection control, after controlling the operating frequency of the
compressor 11 to reach the first target frequency FA1, thecontrol unit 50 controls the operating frequency of thecompressor 11 to be maintained at the first target frequency FA1 for a predetermined time. Subsequently, thecontrol unit 50 controls the operating frequency of thecompressor 11 to change from the first target frequency FA1 to the second target frequency FA2. After controlling the operating frequency of thecompressor 11 to be maintained at the second target frequency FA2 for a predetermined time, thecontrol unit 50 controls the operating frequency of thecompressor 11 to change from the second target frequency FA2 to the necessary operating frequency FN. The first period TA1, in which the operating frequency of thecompressor 11 is controlled to be maintained at the first target frequency FA1 in the second protection control, is shorter than the first period TX1, in which the operating frequency of thecompressor 11 is controlled to be maintained at the first target frequency FX1 in the first protection control. Also, the second period TA2, in which the operating frequency of thecompressor 11 is controlled to be maintained at the second target frequency FA2, is shorter than the second period TX2, in which the operating frequency of thecompressor 11 is controlled to be maintained at the second target frequency FX2 in the first protection control. - Graph GA shown in
Fig. 3 shows changes in the operating frequency of thecompressor 11 in the second protection control. As indicated by graph GA, at time t1, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 reaches the first target frequency FA1. From time t1 to time t2 (during the period TA1), thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 is maintained at the first target frequency FA1. At time t2, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 changes from the first target frequency FA1 to the second target frequency FA2. From time t2 to time t4 (during the period TA2), thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 is maintained at the second target frequency FA2. At time t4, thecontrol unit 50 drives thecompressor 11 so that the operating frequency of thecompressor 11 changes from the second target frequency FA2 to the necessary operating frequency FN. As described above, a period TA (from time t1 to time t4) from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN in the second protection control is shorter than a period TX (from time t1 to time t8) from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN in the first protection control. - The probability of occurrence of problems with the
compressor 11 will now be described. - The probability of occurrence of problems with the
compressor 11 may be estimated using the indoor air temperature (room temperature) and the outdoor air temperature (outdoor temperature). More specifically, the probability of occurrence of problems with thecompressor 11 may be estimated based on the room temperature DA, the ambient temperature DOA, and the difference in temperature between the room temperature DA and the ambient temperature DOA. A temperature condition under which the probability of occurrence of problems with thecompressor 11 is low when starting the heating operation, and a temperature condition under which the probability of occurrence of problems with thecompressor 11 is low when starting the cooling operation are found through tests conducted by the inventors of the present application. - When starting the heating operation, if the room temperature DA is high, the need for quickly increasing the room temperature DA is low, that is, the need for increasing the heating performance is low. When starting the cooling operation, if the room temperature DA is low, the need for quickly decreasing the room temperature DA is low, that is, the need for increasing the cooling performance is low. As described above, when the need for increasing the heating performance or the cooling performance is low, the first protection control is executed as the compressor protection control, so that problems with the
compressor 11 are more assuredly avoided. -
Fig. 4 is an example of results of tests conducted by the inventors of the present application to determine whether problems with thecompressor 11 occur when the second protection control of the compressor protection control is executed at the time of starting the heating operation, with changes in the room temperature DA, the ambient temperature DOA, and the difference in temperature between the room temperature DA and the ambient temperature DOA. InFig. 4 , the vertical axis indicates the room temperature DA, and the horizontal axis indicates the ambient temperature DOA. In this temperature map, diagonal lines indicate indoor-outdoor temperature differences, that is, differences (DA-DOA) in temperature between the room temperature DA and the ambient temperature DOA. In the temperature map shown inFig. 4 , the shaded section indicates an example of a temperature region (hereafter, referred to as "temperature region RL") in which when starting the heating operation, the probability of occurrence of problems with thecompressor 11 is low and the need for increasing the heating performance is high. The temperature region RL is surrounded by conditions of the room temperature DA being less than or equal to 20°C, the ambient temperature DOA being greater than or equal to 0°C, and the indoor-outdoor temperature difference being less than or equal to X5. An example of the indoor-outdoor temperature difference X5 is 10°C. More specifically, when the ambient temperature DOA is greater than or equal to 0°C and the indoor-outdoor temperature difference is less than or equal to 10°C, if the second protection control of the compressor protection control is executed at the time of starting the heating operation, the probability of occurrence of problems with thecompressor 11 is low. In other words, when the ambient temperature DOA is less than 0°C or the indoor-outdoor temperature difference is greater than 10°C, if the second protection control of the compressor protection control is executed at the time of starting the heating operation, the probability of occurrence of problems with thecompressor 11 is high. When the room temperature DA is greater than 20°C and the indoor-outdoor temperature difference is less than or equal to 10°C, if the second protection control of the compressor protection control is executed at the time of starting the heating operation, the probability of occurrence of problems with thecompressor 11 is low. However, the heating performance does not need to be increased. - Although not shown in the drawings, in the same manner as the heating operation, for the cooling operation, the inventors of the present application conducted tests to determine whether problems with the
compressor 11 occur when the second protection control of the compressor protection control is executed at the time of starting the cooling operation, with changes in the room temperature DA, the ambient temperature DOA, and the difference in temperature between the room temperature DA and the ambient temperature DOA. Temperature conditions under which when starting the cooling or heating operation, the probability of occurrence of problems with thecompressor 11 is low, and the need for increasing the cooling or heating performance is high are determined based on these tests and described below. Such temperature conditions of the cooling or heating operation are stored in thecontrol unit 50, for example, as a map MP1 shown inFig. 5 for the heating operation and a map MP2 shown inFig. 6 for the cooling operation. - [Heating Operation] (a1) The room temperature DA is less than or equal to a first determination temperature DAX1 (room temperature threshold value) (DA≤DAX1). (a2) The ambient temperature DOA is in a first temperature range (DOAL1≤DOA≤DOAH1). Here, DOAL1 denotes the lower limit value of the first temperature range, and DOAH1 denotes the upper limit value of the first temperature range. (a3) The difference in temperature between the room temperature DA and the ambient temperature DOA is less than or equal to a first determination temperature difference DDX1 (temperature difference threshold value) (DA-DOA≤DDX).
- The first determination temperature DAX1 is a determination value of the room temperature that determines whether the heating performance needs to be increased. An example of the first determination temperature DAX1 is 13°C. The lower limit value DOAL1 of the first temperature range is a determination value of the ambient temperature that determines whether the probability of occurrence of problems with the
compressor 11 is low when starting the heating operation. An example of the lower limit value DOAL1 is 0°C. The upper limit value DOAH1 of the first temperature range is a determination value of the ambient temperature that determines whether the heating performance needs to be increased. An example of the upper limit value DOAH1 is 24°C. The first determination temperature difference DDX1 is a determination value of the indoor-outdoor temperature difference that determines whether the probability of occurrence of problems with thecompressor 11 is low when starting the heating operation. An example of the first determination temperature difference DDX1 is 10°C. - [Cooling Operation] (b1) The room temperature DA is greater than or equal to a second determination temperature DAX2 (room temperature threshold value) (DA≥DAX2). (b2) The ambient temperature DOA is in a second temperature range (DOAL2≤DOA≤DOAH2). Here, DOAL2 denotes the lower limit value of the second temperature range, and DOAH2 denotes the upper limit value of the second temperature range. (b3) The difference in temperature between the room temperature DA and the ambient temperature DOA is less than or equal to a second determination temperature difference DDX2 (temperature difference threshold value) (DA-DOA≤DDX2).
- The second determination temperature DAX2 is a determination value of the room temperature that determines whether the cooling performance needs to be increased. An example of the second determination temperature DAX2 is 25°C. The lower limit value DOAL2 of the second temperature range is a determination value of the ambient temperature that determines whether the cooling performance needs to be increased. An example of the lower limit value DOAL2 is 25°C. The upper limit value DOAH2 of the second temperature range is a determination value of the ambient temperature that determines whether the probability of occurrence of problems with the
compressor 11 is low when starting the cooling operation. An example of the upper limit value DOAH2 is 45°C. The second determination temperature difference DDX2 is a determination value of the indoor-outdoor temperature difference that determines whether the probability of occurrence of problems with thecompressor 11 is low when starting the cooling operation. An example of the second determination temperature difference DDX2 is -10°C. - The
control unit 50 uses the map MP1 to select the first protection control and the second protection control when starting the heating operation based on the temperature conditions a1, a2, and a3 of the heating operation. Thecontrol unit 50 uses the map MP2 to select the first protection control and the second protection control when starting the cooling operation based on the temperature conditions b1, b2, and b3 of the cooling operation. - In the map MP1, the vertical axis indicates the room temperature DA, and the horizontal axis indicates the ambient temperature DOA. In the map MP1, the diagonal line indicates a boundary condition of the indoor-outdoor temperature difference. In the map MP1, the shading indicates a temperature region R1 in which all of the temperature conditions a1, a2, and a3 are satisfied. More specifically, the second protection control is selected in the temperature region R1, and the first protection control is selected in a region excluding the temperature region R1.
- The temperature region R1 of the map MP1 may be the same as the temperature region RL shown in
Fig. 4 . More specifically, in the temperature conditions a1, a2, and a3 of the heating operation, the first determination temperature DAX1 may be 20°C, the lower limit value DOAL1 of the first temperature range may be 0°C, the upper limit value DOAH1 may be 30°C, and the first determination temperature difference DDX1 may be 10°C. - In the map MP2, the vertical axis indicates the room temperature DA, and the horizontal axis indicates the ambient temperature DOA. In the map MP2, the diagonal line indicates a boundary condition of the indoor-outdoor temperature difference. In the map MP2, the shading indicates a temperature region R2 in which all of the temperature conditions b1, b2, and b3 are satisfied. More specifically, the second protection control is selected in the temperature region R2, and the first protection control is selected in a region excluding the temperature region R2.
- In the first activation control, the
control unit 50 uses the map MP1 to select one of the first protection control and the second protection control when starting the heating operation, and uses the map MP2 to select one of the first protection control and the second protection control when starting the cooling operation. - The procedures of the first activation control will now be described with reference to
Fig. 7 . - In step S11, the
control unit 50 determines whether the heating operation is instructed to be performed. The determination of step S11 is made, for example, based on whether thecontrol unit 50 receives an instruction to perform the heating operation from theremote controller 51. When determining in step S11 that the heating operation is instructed to be performed (step S11: YES), thecontrol unit 50 selects the map MP1 in step S12. In step S13, thecontrol unit 50 determines whether the coordinates specified by the room temperature DA and the ambient temperature DOA are in the range of the temperature region R1 in the map MP1. When determining that the coordinates specified by the room temperature DA and the ambient temperature DOA are in the range of the temperature region R1 (step S13: YES), that is, when determining that all of the temperature conditions a1 to a3 are satisfied, thecontrol unit 50 selects the second protection control in step S14. When determining that the coordinates specified by the room temperature DA and the ambient temperature DOA are outside the range of the temperature region R1 (step S13: NO), that is, when determining that at least one of the temperature conditions a1 to a3 is not satisfied, thecontrol unit 50 selects the first protection control in step S15. - When determining in step S11 that the heating operation is not instructed to be performed (step S11: NO), the
control unit 50 determines in step S16 whether the cooling operation is instructed to be performed. The determination of step S16 is made, for example, based on whether thecontrol unit 50 receives an instruction to perform the cooling operation from theremote controller 51. When determining in step S16 that the cooling operation is instructed to be performed (step S16: YES), thecontrol unit 50 selects the map MP2 in step S17. In step S18, thecontrol unit 50 determines whether the coordinates specified by the room temperature DA and the ambient temperature DOA are in the range of the temperature region R2 in the map MP2. When determining that the coordinates specified by the room temperature DA and the ambient temperature DOA are in the range of the temperature region R2 (step S18: YES), that is, when determining that all of the temperature conditions b1 to b3 are satisfied, thecontrol unit 50 proceeds to step S14. That is, thecontrol unit 50 selects the second protection control. When determining that the coordinates specified by the room temperature DA and the ambient temperature DOA are outside the range of the temperature region R2 (step S18: NO), that is, when determining that at least one of the temperature conditions b1 to b3 is not satisfied, thecontrol unit 50 selects the first protection control in step S19. - When determining in step S16 that the cooling operation is not instructed to be performed, the
control unit 50 terminates the first activation control. In this case, a dehumidifying operation is an example of an operation other than the heating operation and the cooling operation. - The present embodiment has the following advantages.
- (1-1) When performing the cooling or heating operation, the
control unit 50 uses the map MP1 or the map MP2 to execute one of the first protection control and the second protection control. The time from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN in the second protection control is shorter than the time from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN in the first protection control. In this configuration, the second protection control is executed to shorten the time from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN. Thus, the cooling or heating operation starts up quickly. As a result, the time from when the cooling or heating operation is started to when the room temperature DA reaches the set temperature is shortened, thereby increasing the heating performance or the cooling performance. - (1-2) The first target frequency FA1 in the second protection control is greater than the first target frequency FX1 in the first protection control. The second target frequency FA2 in the second protection control is greater than the second target frequency FX2 in the first protection control. In this configuration, the number of target frequencies that are set in the second protection control from when the
compressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN is less than the number of target frequencies that are set in the first protection control from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN. The second protection control shortens the time from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN. This allows for a quick startup of the cooling or heating operation. - (1-3) The first period TA1, in which the operating frequency of the
compressor 11 is controlled to be maintained at the first target frequency FA1 in the second protection control, is shorter than the first period TX1, in which the operating frequency of thecompressor 11 is controlled to be maintained at the first target frequency FX1 in the first protection control. The second period TA2, in which the operating frequency of thecompressor 11 is controlled to be maintained at the second target frequency FA2 in the second protection control, is shorter than the second period TX2, in which the operating frequency of thecompressor 11 is controlled to be maintained at the second target frequency FX2 in the first protection control. In this configuration, the number of target frequencies that are set in the second protection control from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN is less than the number of target frequencies that are set in the first protection control from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN. The second protection control shortens the time from when thecompressor 11 is activated to when the operating frequency of thecompressor 11 reaches the necessary operating frequency FN. This allows for a quick startup of the cooling or heating operation. - (1-4) The
control unit 50 uses the map MP1 in the cooling operation to select one of the first protection control and the second protection control and uses the map MP2 in the heating operation to select one of the first protection control and the second protection control. As described above, the condition for executing the second protection control in the cooling operation differs from the condition for executing the second protection control in the heating operation. That is, the conditions are separately set for the cooling operation and the heating operation. This allows thecontrol unit 50 to appropriately execute the second protection control in the cooling operation or the heating operation. - (1-5) In the map MP1 and the map MP2, the conditions for executing the second protection control are specified based on the room temperature DA, the ambient temperature DOA, and the indoor-outdoor temperature difference. As described above, the
indoor temperature sensor 52 and theoutdoor temperature sensor 53, which are normally included in theair conditioner 1, are used to set the conditions for executing the second protection control. The use of the room temperature DA and the ambient temperature DOA, which are easily obtained information about theair conditioner 1, eliminates the need for a dedicated sensor that sets the conditions for executing the second protection control. This limits increases in the cost of theair conditioner 1. - A second embodiment of an
air conditioner 1 will now be described with reference toFigs. 1 and8 . Theair conditioner 1 of the present embodiment differs from theair conditioner 1 of the first embodiment in the first activation control. In the following description, components of theair conditioner 1 refer to the components of theair conditioner 1 shown inFig. 1 . - When the operation of the
air conditioner 1 is stopped, the refrigerant may condense and accumulate at a side corresponding to the lower one of the indoor air temperature and the outdoor air temperature. When the outdoor air temperature is lower than the indoor air temperature, a stagnation phenomenon is generated, that is, the liquid refrigerant dissolves and accumulates in the lubricant oil of thecompressor 11 or the liquid refrigerant accumulates in theoutdoor heat exchanger 13. When the stagnation phenomenon is generated and thecompressor 11 is activated in the heating operation, if the increase rate of the operating frequency of thecompressor 11 is increased, generation of oil foaming in thecompressor 11 is facilitated. This causes a failure of thecompressor 11. Also, when the stagnation phenomenon is generated and thecompressor 11 is activated in the cooling operation, if the increase rate of the operating frequency of thecompressor 11 is increased, generation of oil foaming in thecompressor 11 is facilitated in the same manner as in the heating operation. - In this regard, the
control unit 50 executes a refrigerant discharge activation operation to avoid a failure of thecompressor 11 caused by the stagnation phenomenon when starting the cooling or heating operation. In the refrigerant discharge activation operation that is performed when starting the heating operation, when activating thecompressor 11 in accordance with the start of the heating operation, thecontrol unit 50 operates thecompressor 11 with the four-way switching valve 12 switched to the reverse cycle (cooling mode connection state) for a predetermined time (e.g., one minute). This allows the liquid refrigerant accumulated in theoutdoor heat exchanger 13 to flow to theindoor heat exchanger 21. In the refrigerant discharge activation operation, the liquid refrigerant in theindoor heat exchanger 21 is evaporated by theindoor heat exchanger 21 and becomes gas refrigerant. The gas refrigerant is drawn into thecompressor 11. This limits generation of oil foaming in thecompressor 11. Also, in the refrigerant discharge activation operation that is performed when starting the cooling operation, when activating thecompressor 11 in accordance with the start of the cooling operation, thecontrol unit 50 operates thecompressor 11 with the four-way switching valve 12 switched to the reverse cycle (heating mode connection state) for a predetermined time (e.g., one minute). This allows the liquid refrigerant accumulated in theindoor heat exchanger 21 to flow to theoutdoor heat exchanger 13. In the refrigerant discharge activation operation, the liquid refrigerant in theoutdoor heat exchanger 13 is evaporated by theoutdoor heat exchanger 13 and becomes gas refrigerant. The gas refrigerant is drawn into thecompressor 11. This limits generation of oil foaming in thecompressor 11. As described above, when the refrigerant discharge activation operation is performed at a start of the cooling or heating operation, the probability of occurrence of problems with thecompressor 11 is lowered. - In this regard, in the present embodiment, when the refrigerant discharge activation operation is performed, the
control unit 50 executes a second activation control that selects the second protection control after the refrigerant discharge activation operation. The procedures of the second activation control will now be described with reference toFig. 8 . - In step S21, the
control unit 50 determines whether the refrigerant discharge activation operation is performed. When determining in step S21 that the refrigerant discharge activation operation is performed (step S21: YES), thecontrol unit 50 determines in step S22 whether the refrigerant discharge activation operation is completed. When determining in step S22 that the refrigerant discharge activation operation is completed (step S22: YES), thecontrol unit 50 selects the second protection control in step S23. When determining in step S22 that the refrigerant discharge activation operation is not completed (step S22: NO), thecontrol unit 50 again proceeds to the determination of step S22. - When determining in step S21 that the refrigerant discharge activation operation is not performed (step S21: NO), the
control unit 50 proceeds to the first activation control in step S24. Thecontrol unit 50 selects one of the first protection control and the second protection control based on the first activation control. - The present embodiment has the following advantages.
(2-1) When the refrigerant discharge activation operation is performed, thecontrol unit 50 executes the second protection control. When the refrigerant discharge activation operation has been completed, the probability of occurrence of problems with thecompressor 11 is lowered. Execution of the second protection control after the refrigerant discharge activation operation allows the operating frequency of thecompressor 11 to reach the necessary operating frequency FN quickly after the refrigerant discharge activation operation. Thus, the cooling or heating operation starts up quickly. - The description related to the above embodiments exemplifies, without any intention to limit, applicable forms of an air conditioner according to the present disclosure. In addition to the embodiments described above, the air conditioner according to present disclosure is applicable to, for example, modified examples of the above embodiment that are described below and combinations of at least two of the modified examples that do not contradict each other.
- In the embodiments, the control executed on the
compressor 11 to increase the operating frequency of thecompressor 11 to the necessary operating frequency FN in the second protection control may be changed in any manner. More specifically, the control may be changed in any manner on condition that the time for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN in the second protection control is shorter than the time for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN in the first protection control. The second protection control may be changed, for example, as described below in (A) to (F). (A) The first target frequency FA1 and the second target frequency FA2 may be changed in any manner. For example, the first target frequency FA1 and the second target frequency FX2 may have different values. In an example, the value of the first target frequency FA1 may be greater than the value of the second target frequency FX2 and less than the value of the third target frequency FX3. In another example, the second target frequency FA2 may be equal to the fourth target frequency FX4. (B) The first period TA1 and the second period TA2, during which thecompressor 11 respectively maintains the first target frequency FA1 and the second target frequency FA2, may be longer than or equal to the first to fourth periods TX1 to TX4 of the first protection control. (C) The first period TA1 and the second period TA2, during which thecompressor 11 respectively maintains the first target frequency FA1 and the second target frequency FA2, may be changed in any manner. For example, the first period TA1 may differ from the second period TA2. More specifically, the first period TA1 and the second period TA2 may be separately set. (D) The number of target frequencies in the second protection control is not limited to two and may be changed in any manner. That is, the number of target frequencies in the second protection control may be one or three or greater. (E) The modifications (A) to (D) may be combined with one another. (F) When starting the second protection control, the operating frequency of thecompressor 11 may be set to the necessary operating frequency FN. That is, the target frequencies such as the first target frequency FA1 may be omitted. - In the embodiments, the control executed on the
compressor 11 to increase the operating frequency of thecompressor 11 to the necessary operating frequency FN in the first protection control may be changed, for example, as follows. (G) Each of the first to fourth target frequencies FX1 to FX4 may be changed in any manner. For example, the difference between the second target frequency FX2 and the first target frequency FX1 may differ from the difference between the third target frequency FX3 and the second target frequency FX2. The difference between the fourth target frequency FX4 and the third target frequency FX3 may differ from the difference between the third target frequency FX3 and the second target frequency FX2. (H) The first to fourth periods TX1 to TX4, during which thecompressor 11 respectively maintains the first to fourth target frequencies FX1 to FX4, may be changed in any manner. For example, some of the first to fourth periods TX1 to TX4 may differ from the rest of the first to fourth periods TX1 to TX4. (I) The number of target frequencies in the first protection control is not limited to four and may be changed in any manner. That is, the number of target frequencies in the first protection control may be three or five or greater. - In the embodiments, the temperature DF of the discharge pipe of the
compressor 11 and the ambient temperature DOA may be added to the conditions for selecting the first protection control and the second protection control. (c1) The temperature DF of the discharge pipe is greater than or equal to a temperature threshold value DFX (DF≥DFX). (c2) The ambient temperature DOA is greater than or equal to a determination temperature threshold value DOAY (DOA≥DOAY). (c3) The difference in temperature between the temperature DF of the discharge pipe and the ambient temperature DOA is greater than or equal to the temperature difference threshold value DDY (DF-DOA≥DDY). - The temperature threshold value DFX is a threshold value that limits the condition for proceeding to the maps MP1 and MP2 and is set in advance through tests or the like. An example of the temperature threshold value DFX is -3°C. The determination temperature threshold value DOAY is a determination value that limits the condition for proceeding to the maps MP1 and MP2 and is set in advance through tests or the like. An example of the determination temperature threshold value DOAY is -15°C. The temperature difference threshold value DDY is a threshold value that limits the condition for proceeding to the maps MP1 and MP2 and is set in advance through tests or the like.
- The
control unit 50 stores a map MP3 specifying the relationship between the temperature DF of the discharge pipe of thecompressor 11 and the ambient temperature DOA to select the first protection control and the second protection control.Fig. 9 shows an example of the map MP3. In the map MP3, the vertical axis indicates the temperature DF of the discharge pipe of thecompressor 11, and the horizontal axis indicates the ambient temperature DOA. In the map MP3, the diagonal line indicates the boundary condition of the difference in temperature between the temperature DF of the discharge pipe and the ambient temperature DOA. In the map MP3, the unshaded region indicates a temperature region R3 in which all of temperature conditions c1, c2, and c3 are satisfied. - In the first activation control, after determination of step S11 or determination of step S16, when determining that the cooling or heating operation is instructed to be performed, the
control unit 50 determines whether the temperature DF of the discharge pipe and the ambient temperature DOA are in the temperature region R3. More specifically, thecontrol unit 50 determines whether the temperature DF of the discharge pipe of thecompressor 11 and the ambient temperature DOA are in the temperature region R3. When determining that the temperatures are in the temperature region R3, that is, when determining that the temperature conditions c1, c2, and c3 are satisfied, thecontrol unit 50 uses the map MP1 when starting the heating operation to select one of the first protection control and the second protection control, and uses the map MP2 when starting the cooling operation to select one of the first protection control and the second protection control. When determining that the temperature DF of the discharge pipe and the ambient temperature DOA are in a region outside the temperature region R3, that is, when determining that at least one of the temperature conditions c1, c2, and c3 is not satisfied, thecontrol unit 50 executes the first protection control. As described above, when the relationship between the temperature DF of the discharge pipe of thecompressor 11 and the ambient temperature DOA is added to the conditions for executing the second protection control, the second protection control is executed more appropriately in the cooling or heating operation. - In the map MP3 shown in
Fig. 9 , in a temperature region R4 in which the ambient temperature DOA is less than the determination temperature threshold value DOAY, a third protection control that differs from the first protection control and the second protection control may be executed as the compressor protection control. In an example of the third protection control, thecontrol unit 50 controls thecompressor 11 so that the time for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN is longer than the time (the period TX) for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN in the first protection control. - In the map MP3 shown in
Fig. 9 , in a temperature region R5, the ambient temperature DOA is greater than or equal to the determination temperature threshold value DOAY and less than a determination temperature threshold value DOAZ that is greater than the determination temperature threshold value DOAY (DOAZ>DOAY), and the temperature DF of the discharge pipe of thecompressor 11 is less than the temperature threshold value DFX. In the temperature region R5, a fourth protection control that differs from the first protection control and the second protection control may be executed as the compressor protection control. In an example of the fourth protection control, thecontrol unit 50 controls thecompressor 11 so that the time for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN is longer than the time (the period TX) for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN in the first protection control and is shorter than the time for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN in the third protection control. - In the map MP3 shown in
Fig. 9 , in a temperature region R6, the ambient temperature DOA is greater than or equal to the determination temperature threshold value DOAZ, and the difference in temperature between the temperature DF of the discharge pipe and the ambient temperature DOA is less than the temperature difference threshold value DDY. In the temperature region R6, a fifth protection control that differs from the first protection control and the second protection control may be executed as the compressor protection control. In an example of the fifth protection control, thecontrol unit 50 controls thecompressor 11 so that the time for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN is longer than the time (the period TX) for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN in the first protection control and is shorter than the time for the operating frequency of thecompressor 11 to reach the necessary operating frequency FN in the fourth protection control. - In the embodiments, at least one of the temperature condition a1 of the heating operation or the temperature condition b1 of the cooling operation may be omitted from the first activation control.
- In the embodiments, one of the
outdoor controller 16 and theindoor controller 23 may be omitted. For example, when theindoor controller 23 is omitted, theindoor temperature sensor 52 is connected to theoutdoor controller 16 by wire or through wireless communication. In addition, theindoor fan 22 is connected to theoutdoor controller 16 by wire. In this case, theoutdoor controller 16 corresponds to the control unit.
Claims (7)
- An air conditioner, comprising:a compressor (11) in which an operating frequency is changeable; anda control unit (50) that executes a compressor protection control, the compressor protection control increasing the operating frequency of the compressor (11) to a necessary operating frequency (FN) when starting a cooling operation or a heating operation, whereinthe compressor protection control includes a first protection control and a second protection control,the first protection control controls the operating frequency so that a time from when the compressor (11) is activated to when the operating frequency reaches the necessary operating frequency (FN) is relatively long,the second protection control controls the operating frequency so that the time from when the compressor (11) is activated to when the operating frequency reaches the necessary operating frequency (FN) is relatively short, andwhen executing the compressor protection control, if a predetermined condition is satisfied, the control unit (50) executes the second protection control.
- The air conditioner according to claim 1, whereinthe control unit (50) sets a first target frequency (FA1, FX1) and a second target frequency (FA2, FX2) in the compressor protection control,the second target frequency (FA2, FX2) is greater than the first target frequency (FA1, FX1) and is less than the necessary operating frequency (FN),the control unit (50) maintains the operating frequency at the first target frequency (FA1, FX1) for a first period (TA1, TX1) and at the second target frequency (FA2, FX2) for a second period (TA2, TX2) so that the operating frequency is increased in a stepped manner,the first target frequency (FA1) of the second protection control is greater than the first target frequency (FX1) of the first protection control, andthe second target frequency (FA2) of the second protection control is greater than the second target frequency (FX2) of the first protection control.
- The air conditioner according to claim 1 or 2, whereinthe control unit (50) sets a first target frequency (FA1, FX1) and a second target frequency (FA2, FX2) in the compressor protection control,the second target frequency (FA2, FX2) is greater than the first target frequency (FA1, FX1) and is less than the necessary operating frequency (FN),the control unit (50) maintains the operating frequency at the first target frequency (FA1, FX1) for a first period (TA1, TX1) and at the second target frequency (FA2, FX2) for a second period (TA2, TX2) so that the operating frequency is increased in a stepped manner,the first period (TA1) of the second protection control is shorter than the first period (TX1) of the first protection control, andthe second period (TA2) of the second protection control is shorter than the second period (TX2) of the second protection control.
- The air conditioner according to any one of claims 1 to 3, wherein the predetermined condition in the heating operation differs from the predetermined condition in the cooling operation.
- The air conditioner according to any one of claims 1 to 4, wherein the predetermined condition includes an indoor air temperature (DA), an outdoor air temperature (DOA), and a temperature difference (DA-DOA) between the indoor air temperature and the outdoor air temperature.
- The air conditioner according to claim 5, wherein the predetermined condition in the heating operation is that the indoor air temperature (DA) is less than or equal to a room temperature threshold value (DAX1, DAX2), that the outdoor air temperature (DOA) is greater than or equal to an outdoor temperature threshold value (DOAX1, DOAX 2), and that the temperature difference (DA-DOA) between the indoor air temperature (DA) and the outdoor air temperature (DOA) is less than or equal to a temperature difference threshold value (DDX1, DDX2).
- The air conditioner according to any one of claims 1 to 6, wherein the predetermined condition includes a temperature (DF) of a discharge pipe of the compressor and an outdoor air temperature (DOA).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2017209494A JP6601472B2 (en) | 2017-10-30 | 2017-10-30 | Air conditioner |
PCT/JP2018/036016 WO2019087630A1 (en) | 2017-10-30 | 2018-09-27 | Air conditioner |
Publications (3)
Publication Number | Publication Date |
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EP3705808A1 true EP3705808A1 (en) | 2020-09-09 |
EP3705808A4 EP3705808A4 (en) | 2020-11-18 |
EP3705808B1 EP3705808B1 (en) | 2022-08-03 |
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EP18873146.7A Active EP3705808B1 (en) | 2017-10-30 | 2018-09-27 | Air conditioner |
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EP (1) | EP3705808B1 (en) |
JP (1) | JP6601472B2 (en) |
CN (1) | CN111279138B (en) |
WO (1) | WO2019087630A1 (en) |
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JP7014988B1 (en) | 2020-12-02 | 2022-02-02 | ダイキン工業株式会社 | Refrigeration equipment |
CN113587373A (en) * | 2021-07-12 | 2021-11-02 | 重庆海尔空调器有限公司 | Method and device for improving shutdown fault of air conditioner and air conditioner |
Family Cites Families (22)
Publication number | Priority date | Publication date | Assignee | Title |
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JPH0445004Y2 (en) * | 1986-10-29 | 1992-10-22 | ||
JPH0623879Y2 (en) * | 1987-05-21 | 1994-06-22 | 株式会社東芝 | Air conditioner |
JP2508191B2 (en) * | 1988-05-31 | 1996-06-19 | ダイキン工業株式会社 | Refrigeration equipment |
JPH04268164A (en) * | 1991-02-22 | 1992-09-24 | Sharp Corp | Air conditioner |
KR0133053B1 (en) * | 1992-06-18 | 1998-04-21 | 강진구 | Method for controlling movement frequency of compressor in airconditioner |
JP3147588B2 (en) | 1993-05-31 | 2001-03-19 | ダイキン工業株式会社 | Refrigeration equipment |
JP3199527B2 (en) * | 1993-08-25 | 2001-08-20 | 三菱電機株式会社 | Refrigeration cycle equipment |
JPH07310959A (en) * | 1994-05-17 | 1995-11-28 | Matsushita Refrig Co Ltd | Air conditioner |
JPH09119693A (en) * | 1995-10-27 | 1997-05-06 | Matsushita Electric Ind Co Ltd | Air conditioner |
JP2005061738A (en) * | 2003-08-18 | 2005-03-10 | Matsushita Electric Ind Co Ltd | Air conditioner |
JP2005274035A (en) * | 2004-03-25 | 2005-10-06 | Matsushita Electric Ind Co Ltd | Operation control device for air-conditioner |
JP2005300056A (en) * | 2004-04-14 | 2005-10-27 | Matsushita Electric Ind Co Ltd | Refrigeration cycle system |
JP2006118731A (en) * | 2004-10-19 | 2006-05-11 | Matsushita Electric Ind Co Ltd | Air conditioner |
JP4734161B2 (en) * | 2006-04-19 | 2011-07-27 | 日立アプライアンス株式会社 | Refrigeration cycle apparatus and air conditioner |
EP2015004B1 (en) * | 2006-04-26 | 2019-03-06 | Toshiba Carrier Corporation | Air conditioner |
JP4916383B2 (en) * | 2007-06-01 | 2012-04-11 | サンデン株式会社 | Start-up control device for electric scroll compressor and start-up control method thereof |
CN102105759B (en) * | 2008-07-23 | 2013-11-13 | 开利公司 | Methods and systems for compressor operation |
JP6076583B2 (en) * | 2011-01-19 | 2017-02-08 | 三菱重工業株式会社 | heat pump |
CN102798184B (en) * | 2012-08-13 | 2015-08-12 | 北京德能恒信科技有限公司 | A kind of heat pipe hot pump hybrid system |
JP5959373B2 (en) * | 2012-08-29 | 2016-08-02 | 三菱電機株式会社 | Refrigeration equipment |
JP6289611B2 (en) * | 2014-03-17 | 2018-03-07 | 三菱電機株式会社 | Refrigeration cycle equipment |
JP6079707B2 (en) * | 2014-06-27 | 2017-02-15 | ダイキン工業株式会社 | air conditioner |
-
2017
- 2017-10-30 JP JP2017209494A patent/JP6601472B2/en active Active
-
2018
- 2018-09-27 WO PCT/JP2018/036016 patent/WO2019087630A1/en unknown
- 2018-09-27 CN CN201880069422.0A patent/CN111279138B/en active Active
- 2018-09-27 EP EP18873146.7A patent/EP3705808B1/en active Active
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JP6601472B2 (en) | 2019-11-06 |
CN111279138B (en) | 2021-06-11 |
WO2019087630A1 (en) | 2019-05-09 |
EP3705808A4 (en) | 2020-11-18 |
EP3705808B1 (en) | 2022-08-03 |
JP2019082279A (en) | 2019-05-30 |
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