JPWO2020111200A1 - Air conditioner - Google Patents

Abstract

When the defrosting of any of the plurality of air conditioners is started, the defrosting start conditions of the remaining air conditioners other than the air conditioner to be defrosted are changed.

Description

The present invention relates to an air conditioner including a plurality of air conditioners.

An air conditioner that has a heat pump refrigeration cycle that circulates refrigerant by connecting a compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and an indoor heat exchanger in that order, and draws heat from the outside air to heat the indoor air. As the heating progresses, frost gradually adheres to the surface of the outdoor heat exchanger that functions as an evaporator, and when the amount of frost formed increases, the amount of heat pumped from the outside air decreases and the heating capacity decreases.

As a countermeasure, the frost formation status of the outdoor heat exchanger is monitored from the temperature of the outdoor heat exchanger, and when the frost formation increases, the discharge refrigerant (high temperature refrigerant) of the compressor is directly supplied to the outdoor heat exchanger. , The defrosting operation is executed to defrost the outdoor heat exchanger with the heat of the high temperature refrigerant.

JP-A-2010-121798

In the case of an air conditioner that air-conditions the same air-conditioning area with multiple air conditioners, if multiple air conditioners enter the defrosting operation at the same time, the heating capacity tends to be insufficient and the indoor temperature of the air-conditioning area drops. May cause discomfort to the resident.

An object of the present embodiment is to provide an air conditioner capable of suppressing a decrease in indoor temperature due to defrosting as much as possible.

The air conditioner according to claim 1 includes a heat pump type refrigeration cycle including a compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and an indoor heat exchanger, and when the defrosting start condition of the outdoor heat exchanger is satisfied. With multiple air conditioners performing defrosting operations on the outdoor heat exchanger; when defrosting any of these air conditioners begins, the remaining air conditioners except the air conditioner that begins defrosting are removed. It is equipped with a controller that changes the frost start condition and;

The figure which shows the structure of one Embodiment. The flowchart which shows the control which the master unit executes with respect to the communication with the slave unit in one Embodiment. The flowchart which shows the control which the master unit and the slave unit execute respectively in one Embodiment. The figure which shows the execution of the defrost operation of each air conditioner in one Embodiment, and the change of the defrost start condition with the execution.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the indoor units 20 of a plurality of air conditioners 1a, 1b, ... 1n constituting the air conditioner are arranged in the same air conditioning area R.

The air conditioner 1a, which is the master unit, has a heat pump type refrigeration cycle in which the compressor 11, the four-way valve 12, the outdoor heat exchanger 13, the decompressor, for example, the electric expansion valve 14, and the indoor heat exchanger 21 are sequentially connected by piping. Be prepared.

During the cooling operation, the refrigerant discharged from the compressor 11 flows into the outdoor heat exchanger (condenser) 13 through the four-way valve 12, and the refrigerant flowing out from the outdoor heat exchanger 13 passes through the electric expansion valve 14. The refrigerant that flows into the indoor heat exchanger (evaporator) 21 and flows out from the indoor heat exchanger 21 is sucked into the compressor 11 through the four-way valve 12.

During the heating operation, the refrigerant discharged from the compressor 11 flows into the indoor heat exchanger (condenser) 21 through the four-way valve 12 by switching the flow path of the four-way valve 12, as shown by the arrow. The refrigerant flowing out of the indoor heat exchanger 21 flows into the outdoor heat exchanger (evaporator) 13 through the electric expansion valve 14, and the refrigerant flowing out from the outdoor heat exchanger 13 passes through the four-way valve 12 to the compressor 11. Is sucked into. During the defrosting operation of the outdoor heat exchanger 13 during the heating operation, the return of the flow path of the four-way valve 12 forms the same flow of refrigerant as during the cooling operation.

An outdoor fan 15 that sucks in outside air and passes it through the outdoor heat exchanger 13 is arranged in the vicinity of the outdoor heat exchanger 13, and an outside air temperature sensor 16 that detects the outside air temperature To is arranged in the suction air passage of the outdoor fan 15. An indoor fan 22 that sucks indoor air in the air-conditioned area and passes it through the indoor heat exchanger 21 is arranged near the indoor heat exchanger 21, and an indoor temperature sensor 23 that detects the temperature (referred to as indoor temperature) Ta of the indoor air is an indoor fan. It is arranged in 22 suction air passages.

The compressor 11, the four-way valve 12, the outdoor heat exchanger 13, the electric expansion valve 14, the outdoor fan 15, and the outdoor air temperature sensor 16 are housed in the outdoor unit 10 together with the outdoor controller 18a. The temperature sensor 23 is housed in the indoor unit 20 together with the indoor controller 24a. The outdoor controller 18a and the indoor controller 24a are connected to each other via a serial signal line 31 for power supply voltage synchronization, and the indoor controller 24a is a remote control type actuator (abbreviated as a remote controller) for operation operation and operation condition setting. ) 33 is connected via the cable 32. The remote controller 33 is attached to the wall surface of the air conditioning area or the like and can be easily operated by the user.

The outdoor controller 18a is composed of a microcomputer and its peripheral circuits, controls the compressor 11, the four-way valve 12, the electric expansion valve 14, and the outdoor fan 15 in response to an instruction from the indoor controller 24a, and detects the outside air temperature sensor 16. Data such as temperature (referred to as outside air temperature) To and detected temperature (referred to as heat exchanger temperature) Te of the heat exchange temperature sensor 17 are sent to the indoor controller 24a by the serial signal line 31.

The indoor controller 24a is composed of a microcomputer and its peripheral circuits, and controls the operation of the air conditioner 1a according to the operation of the remote controller 33, the operating conditions set by the remote controller 33, the transmission data from the outdoor controller 18a, and the like. Further, the indoor controller 24a stores the defrosting start condition for the outdoor heat exchanger 13 in advance in the internal memory, and executes the defrosting operation for the outdoor heat exchanger 13 when the defrosting start condition is satisfied.

The defrosting start condition is a reference value Teo determined according to the heat exchanger temperature (detection temperature of the heat exchange temperature sensor 17) Te of the outdoor heat exchanger 13 and the heat exchanger temperature Te of the outdoor heat exchanger 13 at the start of heating. The first defrosting start condition that the difference ΔTe (= Teo-Te) is equal to or higher than the threshold value A, and the limit that the heat exchanger temperature Te of the outdoor heat exchanger 13 after a certain period of time and t2 from the start of heating is predetermined. The second defrosting start condition of less than the value Tex is included. The threshold value A is a value selected according to the outside air temperature To. When To ≧ 0 ° C., for example, 6 ° C. is selected, and when 0 ° C.> To ≧ -10 ° C., for example, 4 ° C. is selected, and To In the case of <-10 ° C, for example, 2 ° C is selected.

A bus line 40 for control and data transmission is connected between the indoor controller 24a and the indoor controllers 24b to 24n.

The air conditioners 1b to 1n are different from the air conditioners 1a only in that they have the outdoor controllers 18b to 24n and the indoor controllers 24b to 24n, and the basic configuration is the same as that of the air conditioners 1a.

The indoor controllers 24b to 24n are composed of a microcomputer and its peripheral circuits, and comprehensively control the operation of each air conditioner in response to transmission data from the outdoor controllers 18b to 18n and instructions from the indoor controllers 24a, respectively.

Further, the indoor controllers 24b to 24n store the defrosting start condition for each outdoor heat exchanger 13 in advance in the internal memory, and when the defrosting start condition is satisfied, the indoor heat exchanger 13 is defrosted. Frost operation is performed with the outdoor controllers 18b-18n. The defrosting start condition is the same as the defrosting start condition (first defrosting start condition and second defrosting start condition) of the indoor controller 24a.

When the group control mode for controlling the air conditioners 1a, 1b, ... 1n as one group is set by the remote controller 33, the air conditioner 1a and the indoor controller 24a function as the master unit which is the center of control, and the rest. The air conditioners 1b to 1n and the indoor controllers 24b to 24n function as slave units according to the instructions of the master unit.

The indoor controller 24a of the air conditioner 1a includes a first control unit C1, a second control unit C2, a third control unit C3, and a fourth control unit C4 as main functions related to the linkage between the master unit and the slave unit.

The first control unit C1 executes mutual communication between the indoor controllers 24a to 24n periodically and as needed via the data bus line 40. Through this communication, it is possible for the master unit and the slave unit to mutually recognize whether or not the defrosting start condition is satisfied and the operating state.

The second control unit C2 starts defrosting when the defrosting start condition of any of the air conditioners 1a to 1n is satisfied and the air conditioner starts the defrosting operation. Change the defrosting start conditions of the remaining air conditioners except for the machine (air conditioner for which the defrosting start condition is satisfied) to the direction in which the establishment is delayed ("delayed defrosting" mode).

The third control unit C3 delays the delay when the air conditioner that satisfies the defrost start condition enters the defrost operation and the defrost operation ends after the delay direction is changed by the second control unit C2. Change the defrosting start condition of the air conditioner whose direction has been changed to the direction in which the establishment is earlier than usual (“early defrosting” mode).

When the defrosting start condition of the air conditioner whose delay direction has been changed by the second control unit C2 is satisfied and the air conditioner enters the defrosting operation, the fourth control unit C4 performs the defrosting operation. Reduce the start-up capacity of the air conditioner to resume heating after the end of.

[Control of master unit]
The control executed by the indoor controller 24a of the master unit in relation to the communication with the slave unit will be described with reference to the flowchart of FIG. Steps S1, S2 ... In the flowchart are simply abbreviated as S1, S2 ...

When the start operation of the heating operation is performed by the remote controller 33 (YES in S1), the indoor controller 24a instructs the indoor controllers 24b to 24n to start the heating operation (S2), and the target room set by the remote controller 33. The temperature (also referred to as the set temperature) Ts is instructed to the indoor controllers 24b to 24n (S3). Then, after the start of the heating operation, the indoor controller 24a monitors the "defrosting" notification (notification that the defrosting start condition is satisfied) of the indoor controller 24a and the indoor controllers 24b to 24n (S4). When there is no "defrosting" notification (NO in S4), the indoor controller 24a monitors the "defrosting end" notification (notification that the defrosting operation is completed) of the indoor controller 24a and the indoor controllers 24b to 24n. (S6). When there is no "defrosting end" notification (NO in S6), the indoor controller 24a monitors the stop operation of the remote controller 33 (S8).

When there is no stop operation (NO in S8), the indoor controller 24a returns to S3 and repeats the same process as described above. When there is a stop operation (YES in S8), the indoor controller 24a instructs the indoor controllers 24b to 24n to stop the heating operation (S9).

In the determination of S4, when there is a "defrosting" notification from any of the indoor controllers 24a and the indoor controllers 24b to 24n (YES in S4), the indoor controllers 24a are all the indoor controllers 24b to the slave units. Notifying 24n of "defrosting" (S5), the process proceeds to the determination of S8.

In the determination of S6, when there is a "defrosting end" notification from any of the indoor controllers 24a and the indoor controllers 24b to 24n (YES in S6), the indoor controllers 24a are all the indoor controllers 24b to the slave units. Notifying 24n of "the end of defrosting" (S7), the process proceeds to the determination of S8.

[Control of master unit and slave unit]
The control executed by the master unit and the slave unit will be described with reference to the flowchart of FIG. An example of the defrosting operation executed in the air conditioners 1a to 1c and an example of how the defrosting start condition of the air conditioner 1a changes with the execution of the defrosting operation of the air conditioners 1a to 1c. It is shown in FIG.

When there is an instruction to start the heating operation (YES in S11), the indoor controllers 24a and the indoor controllers 24b to 24n start the heating operation of their respective air conditioners (S12), and the target room set by the remote controller 33 is set. Each heating capacity (operating frequency F of each compressor 11) is controlled according to the difference ΔT between the temperature Ts and the indoor temperature Ta detected by the indoor temperature sensor 23 (S13). After a certain period of time t1 (for example, 15 minutes) has elapsed from the start of the heating operation (YES in S14), the indoor controllers 24a to 24n have a predetermined value, for example, from the current heat exchanger temperature Te of each outdoor heat exchanger 13. The value obtained by subtracting 2 ° C. is updated and stored in the internal memory as the reference value Teo (= Te-2 ° C.) for each defrosting start condition (S15). Then, the indoor controllers 24a to 24n monitor the "defrosting" notification (S16).

For example, when the defrosting start condition is satisfied in the indoor controller 24b of the slave unit, the indoor controller 24b notifies the indoor controller 24a of the master unit that "defrosting is in progress". Upon receiving this "defrosting" notification, the indoor controller 24a of the master unit notifies all the indoor controllers 24b to 24n of the slave unit of "defrosting" (YES, S5 in S4).

Hereinafter, the control executed by the indoor controller 24a will be described as a representative of the indoor controllers 24a to 24n that have received the “defrosting” notification.

When there is no "defrosting" notification (NO in S16) and there is no "defrosting completed" notification (NO in S18), the indoor controller 24a performs the "defrosting" mode setting process in S17 and the "defrosting" mode setting process in S19. Bypassing without executing the "early defrosting" mode setting process, the process shifts to the determination of S20, and the reference value Teo (= Te-2 ° C.) stored in S15 above and the heat exchanger temperature of the current outdoor heat exchanger 13 Monitor whether the difference ΔTe (= Teo-Te) from Te is equal to or higher than the threshold value A (S20). The “late defrost” mode setting process in S17 and the “early defrost” mode setting process in S19 By not executing, the setting of "normal defrosting" mode is continued.

When the difference ΔTe is not equal to or greater than the threshold value A (NO in S20; when there is little frost formation), the indoor controller 24a has passed a certain period of time, for example, 40 minutes from the start of the heating operation, and the heat exchange of the outdoor heat exchanger 13 at the present time has passed. It is monitored whether or not the vessel temperature Te is less than a predetermined limit value (for example, −20 ° C.) Tex (S21). If 40 minutes have not passed since the start of the heating operation, or if the current heat exchanger temperature Te of the outdoor heat exchanger 13 is not less than the limit value Tex (NO in S21), the indoor controller 24a is set to the latter stage. It shifts to the determination of the stop instruction of S29.

If the heating operation continues for more than 40 minutes while the outside air temperature To has dropped to, for example, about -20 ° C, the frost in the outdoor heat exchanger 13 may not be completely removed even if the defrosting operation is executed. In order to deal with such a low outside air temperature environment, the above determination of S21 is adopted as a defrosting start condition.

When the difference ΔTe is equal to or greater than the threshold value A (YES in S20), or when a certain period of time, for example, 40 minutes has passed from the start of the heating operation and the heat exchanger temperature Te is less than the limit value Tex (YES in S21), the indoor controller 24a starts the defrosting operation of the air conditioner 1a (S22) based on the determination that the outdoor heat exchanger 13 needs to be defrosted, and sets "during defrosting" to all the indoor units of the slave unit. Notify the controllers 24b to 24n (S23). With the start of this defrosting operation, the high-temperature refrigerant discharged from the compressor 11 is directly supplied to the outdoor heat exchanger 13 through the four-way valve 12, and adheres to the surface of the outdoor heat exchanger 13 by the heat of the high-temperature refrigerant. The frost that has formed is removed.

After the start of the defrosting operation, the indoor controller 24a waits for the establishment of the defrosting end condition determined based on, for example, the heat exchanger temperature Te of the outdoor heat exchanger 13 (S24).

When the defrosting end condition is satisfied (YES in S24), the indoor controller 24a ends the defrosting operation of the air conditioner 1a and notifies all the indoor controllers 24b to 24n of the slave unit that the defrosting end condition is satisfied. (S25). Then, since the indoor controller 24a continues to set the "normal defrosting" mode in which the reference value Theo and the limit value Tex are not changed at this point (YES in S26), the shift release process in the next S27 is performed. Bypassing without executing and restarting the heating operation (S28). When the heating operation is restarted, the indoor controller 24a bypasses and heats the room without executing the capacity reduction process of S30 because the setting of the "normal defrosting" mode continues at this point (YES in S29). The operation stop instruction is monitored (S31). If there is no stop instruction (NO in S31), the process returns to S16 and the same process as described above is repeated.

In the determination of S16, when there is a "defrosting" notification (YES in S16), the indoor controller 24a newly adds a predetermined value, for example, 1 ° C., from the initial reference value Teo updated and stored in S15. The reference value Teo (= initially Teo-1 ° C.) is stored in the internal memory, and the new limit value Tex is obtained by subtracting a predetermined value, for example, 1 ° C. from the limit value Tex for the heat exchanger temperature Te of the outdoor heat exchanger 13. It is stored in the internal memory as (= initial Tex-1 ° C.) (S17). That is, the defrosting start condition is changed in a direction in which the establishment is delayed more than usual. This change sets the "late defrost" mode.

Subsequently, the indoor controller 24a has a threshold value of ΔTe (= new Teo-Te), which is the difference between the stored new reference value Teo (= initial Teo-1 ° C.) and the current heat exchanger temperature Te of the outdoor heat exchanger 13. Monitor whether it is A or higher (S20). When the difference ΔTe is not equal to or greater than the threshold value A (NO in S20), the indoor controller 24a has passed 40 minutes after a certain period of time from the start of the heating operation, and the heat exchanger temperature Te of the outdoor heat exchanger 13 at the present time is S17. It is monitored whether or not it is less than the new limit value Tex (= initial Tex-1 ° C.) stored in (S21).

When the difference ΔTe is equal to or greater than the threshold value A (YES in S20), or when 40 minutes have passed since the start of the heating operation and the heat exchanger temperature Te is less than the limit value Tex (YES in S21), that is, the exclusion. When the frost start condition is satisfied, the indoor controller 24a regardless of the fact that the defrost operation of the air conditioner 1b, which has been in the defrost operation after the defrost start condition is satisfied first, is still ongoing. The defrosting operation of the air conditioner 1a is started (S22), and "defrosting" is notified to the indoor controllers 24b to 24n of the slave unit (S23). After the start of this defrosting operation, the indoor controller 24a waits for the establishment of the defrosting end condition (S24).

When the defrosting end condition is satisfied (YES in S24), the indoor controller 24a ends the defrosting operation of the air conditioner 1a and notifies all the indoor controllers 24b to 24n of the slave unit that the defrosting end condition is satisfied. (S25). Then, since the reference value Teo and the limit value Tex are changed and the "delayed defrost" mode is set in the indoor controller 24a at this point (NO in S26), the reference value Teo and the limit value Tex are set. The change is canceled, the normal defrosting mode is returned (S27), and the heating operation is restarted (S28).

Upon resuming the heating operation, the indoor controller 24a normally sets the operating frequency F of the compressor 11 for a predetermined time because the defrosting operation so far has been in the "slow defrosting" mode (NO in S29). The start-up capacity for resuming heating is reduced to about 80% of the above (S30).

Subsequently, the indoor controller 24a monitors the stop instruction of the heating operation (S31). When there is no stop instruction (NO in S31), the indoor controller 24a shifts to the determination in S16. When there is a stop instruction (YES in S31), the indoor controller 24a stops the heating operation (S32).

As described above, when the defrosting start condition is satisfied in the air conditioner 1b and the air conditioner 1b enters the defrosting operation, all the remaining air conditioners 1a, 1c except the air conditioner 1b ~ Even if the air conditioner 1b starts the defrosting operation by changing the defrosting start condition of 1n to a direction in which the establishment is delayed (-1 ° C.) and setting the "delayed defrosting" mode, At the same time, the other air conditioners 1a, 1c to 1n do not start the defrosting operation. Therefore, it is possible to suppress a decrease in the indoor temperature Ta of the air-conditioned area due to defrosting as much as possible, and it does not cause discomfort to the resident.

Since the indoor controller of the air conditioner receiving the "defrosting" notification simply shifts the reference value Teo and the limit value Tex of the defrosting start condition in each indoor controller, the control of the indoor controllers 24a to 24n is complicated. There is nothing to do.

As the indoor controllers 24b to 24n of the slave unit, it is only necessary to notify the indoor controller 24a of the master unit of the "defrosting" notification, and the notification of the identification information such as the address indicating which the air conditioner of the slave unit is. Is unnecessary. The indoor controller 24a of the master unit only transfers the "defrosting" notification from any of the slave units to all the slave units, and the air conditioner for which the defrosting start condition is satisfied is satisfied. It is not necessary to notify the identification information such as the address indicating which is. Therefore, the communication control between the master unit and the slave unit can be simplified.

Since the timing of defrosting start of the air conditioners 1a to 1n is only shifted by changing the defrosting start conditions, the defrosting operation of any of the air conditioners is not prohibited, and therefore the outdoor of each air conditioner. There is no problem of so-called over-frosting without removing the frost on the heat exchanger 13.

On the other hand, when the air conditioner 1b that has entered the defrosting operation after the defrosting start condition is satisfied first finishes the defrosting operation and the indoor controller 24b issues a "defrosting end" notification (YES in S18). The indoor controller 24a stores the value obtained by adding a predetermined value, for example, 1 ° C. to the initial reference value Teo updated and stored in S15 as a new reference value Teo (= initial Teo + 1 ° C.) in the internal memory and exchanges outdoor heat. The value obtained by adding a predetermined value, for example, 1 ° C. to the preset limit value Tex for the heat exchanger temperature Te of the vessel 13 is stored in the internal memory as a new limit value Tex (= initial Tex + 1 ° C.) (S19). .. That is, the defrosting start condition is changed in the direction in which the establishment is earlier than usual. This sets the "early defrost" mode.

Subsequently, the indoor controller 24a determines whether or not the difference ΔTe (= new Teo-Te) between the stored new reference value Teo and the current heat exchanger temperature Te of the outdoor heat exchanger 13 is equal to or greater than the threshold value A. Monitor (S20). When the difference ΔTe is not equal to or greater than the threshold value A (NO in S20), the indoor controller 24a has passed 40 minutes after a certain period of time from the start of the heating operation, and the heat exchanger temperature Te of the outdoor heat exchanger 13 at the present time is S19. It is monitored whether or not it is less than the new limit value Tex (= initial Tex + 1 ° C.) stored in (S21).

When the air conditioner 1b that has entered the defrosting operation after the defrosting start condition is satisfied first finishes the defrosting operation and restarts the heating, when the defrosting start condition of the air conditioner 1b is satisfied again, There is a possibility that the conditions for starting defrosting of the air conditioners 1a, 1c to 1n in which the "delayed defrosting" mode is set overlap.

Therefore, when the air conditioner 1b that has entered the defrosting operation after the defrosting start condition is satisfied first ends the defrosting operation, the air conditioners 1a and 1c in which the "delayed defrosting" mode is set is set. The defrosting start condition of ~ 1n is changed in a direction in which the establishment is earlier than usual. In this way, by switching the air conditioners 1a, 1c to 1n from the "delayed defrosting" mode to the "early defrosting" mode, the defrosting start condition of the air conditioner 1b that has restarted heating is established at an early stage. The timing of satisfying the defrosting start conditions of the air conditioners 1a, 1c to 1n can be shifted. That is, it is possible to reduce the possibility that the defrosting starts of a plurality of air conditioners will come around at the same timing.

Further, at the timing when any of the air conditioners 1a and 1c to 1n in the "late defrosting" mode starts the defrosting operation, the air conditioner 1b for which the defrosting start condition is satisfied earlier still performs the defrosting operation. It may be running, in which case the defrosting operations of multiple air conditioners will be performed at the same time. When the plurality of air conditioners finish the defrosting operation and restart the heating, the progress of frost formation in the outdoor heat exchanger 13 of each air conditioner becomes the same, and eventually the plurality of air conditioners are removed. There is a possibility that the start of frost will come around again at the same timing.

Therefore, when any one of the air conditioners 1a, 1c to 1n in the "late defrosting" mode enters the defrosting operation, the defrosting operation is completed, and the heating is restarted, the compressor 11 is used for a predetermined time. The operating frequency F of the air conditioner F is suppressed to about 80% of the normal level to reduce the start-up ability of resuming heating. As a result, even if a plurality of air conditioners perform the defrosting operation at the same time, the progress of frost formation in the outdoor heat exchanger 13 of each air conditioner can be made different. That is, it is possible to reduce the possibility that the defrosting starts of a plurality of air conditioners will come around at the same timing.

[Modification example]
In the above embodiment, the reference value Teo and the limit value Tex of the defrost start condition are shifted by -1 ° C as the “late defrost” mode, and the reference value Teo and the limit value Tex of the defrost start condition are set as the early defrost mode. Although the temperature was shifted by + 1 ° C., the value to be shifted is not limited to -1 ° C., and can be appropriately selected according to the capacity of the outdoor heat exchanger 13 and the capacity of the heat pump type refrigeration cycle.

In the above embodiment, the first defrosting start condition that the difference ΔTe (= Teo-Te) between the heat exchanger temperature Te and the reference value Teo is equal to or higher than the threshold value A is used, but the outside air temperature To detected by the outside air temperature sensor 16 is used. May be added to this first defrosting start condition.

In addition, the above-described embodiments and modifications are presented as examples, and are not intended to limit the scope of the invention. This novel embodiment and modification can be implemented in various other forms, and various omissions, rewrites, and changes can be made without departing from the gist of the invention. These embodiments and modifications are included in the gist of the invention as well as in the scope of the invention described in the claims and the equivalent scope thereof.

1a, 1b, ... 1n ... air conditioner, 10 ... outdoor unit, 11 ... compressor, 13 ... outdoor heat exchanger, 18a, 18b, ... 18n ... outdoor controller, 20 ... indoor unit, 24a, 24b, ... 24n ... indoor controller, 33 ... remote control, 40 ... bus line

Claims (4)

It is equipped with a heat pump type refrigeration cycle consisting of a compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and an indoor heat exchanger, and defrosts the outdoor heat exchanger when the conditions for starting defrosting of the outdoor heat exchanger are satisfied. With multiple air conditioners to perform the operation,
When starting defrosting of any of the above air conditioners, a controller that changes the defrosting start conditions of the remaining air conditioners other than the air conditioner that starts defrosting.
An air conditioner characterized by being equipped with. When the defrosting start condition of any of the air conditioners of each of the air conditioners is satisfied, the controller sets the defrosting start condition of the remaining air conditioners excluding the air conditioner for which the defrosting start condition is satisfied. To change the direction of establishment to be delayed from usual,
The air conditioner according to claim 1. The controller is an air conditioner in which the delay direction is changed when the air conditioner satisfying the defrost start condition enters the defrost operation and the defrost operation ends after the change in the delay direction. Change the defrosting start condition of
The air conditioner according to claim 2. When the defrosting start condition of the air conditioner whose delay direction has been changed is satisfied and the air conditioner enters the defrosting operation, the controller is the air conditioner after the defrosting operation is completed. Reduce the start-up capacity of resuming heating,
The air conditioner according to claim 2 or 3, wherein the air conditioner is characterized by the above.

Images