KR101844860B1 - Air conditioner and method for controlling the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner and its control method for securing reliability and improving efficiency. An air conditioner and a control method thereof according to an embodiment of the present invention include a central controller for controlling a plurality of air conditioner units composed of a plurality of cycles so that the middle- And the defrosting operation for each cycle is sequentially performed in accordance with the specified order, thereby improving the operation efficiency and preventing the cooling and heating operation from being stopped, thereby improving the reliability of the product and the convenience of the user.

Description

[0001] The present invention relates to an air conditioner and a control method thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner and a control method thereof, and more particularly, to an air conditioner and its control method for securing reliability and improving efficiency.

Generally, an air conditioner uses a refrigeration cycle of a refrigerant composed of a compressor, a condenser, an expansion mechanism, and an evaporator to cool or heat the room to create a more comfortable indoor environment for the user.

In the case of industrial air conditioners or central air conditioners, water is cooled in a cooler consisting of a compressor, a condenser, an expansion device, and an evaporator, and water in a cooler is used to air the interior of a large building such as a building, a factory or a gymnasium .

Also, the large capacity air conditioner is provided with a plurality of compressors and a heat exchanger, and each of the compressors and the heat exchanger independently operates according to a separate setting so that a plurality of cycles can be formed.

Since each cycle of the large-capacity air conditioner operates independently, it can be added or reduced in units of cycles, and the capacity can be changed as needed according to the size of the load.

However, in the large-capacity air conditioner, although each cycle is operated independently, there arises a problem that a plurality of cycles enter the defrosting operation at the same time when the cycle temperature is similar. If the defrosting operation starts at the same time, the defrosting operation can be started even if defrosting is unnecessary, and the cooling / heating operation can not be performed until the defrosting operation is completed, resulting in a low efficiency problem and inconveniences the user.

The object of the present invention is to control the defrosting operation for a plurality of cycles of the air conditioner so as to limit the number of cycles for performing the defrosting operation to a predetermined number so as to prevent a plurality of cycles exceeding a predetermined number from simultaneously entering the defrosting operation, And to provide a control method for the air conditioner.

In order to accomplish the above object, the air conditioner of the present invention includes a plurality of cycle controllers for individually controlling independent cycles, and a main controller connected to the cycle controller for monitoring and controlling a plurality of cycles An air conditioner unit; And a central controller coupled to the plurality of main controllers to receive, monitor, and control data for a plurality of cycles included in the plurality of the air conditioner units, wherein the central controller comprises: The defrosting control unit sets the number of possible defrosting operations and controls the defrosting operation to be performed to a defrosting operation request equal to or less than the number of simultaneous defrosting operations in a predetermined order corresponding to a defrosting operation request received from each cycle controller connected to the plurality of cycles via the main controller .

According to another aspect of the present invention, there is provided a control method of a central controller connected to a plurality of air conditioner units including a plurality of cycles, the method comprising: a first cycle controller for controlling a first cycle of the plurality of cycles, Comparing the number of cycles in the current defrosting operation with the number of simultaneous defrosting operations when the operation request is received; Transmitting a defrost operation command for the first cycle to the first cycle controller if the number of cycles during the defrosting operation is less than the simultaneous defrost allowable number; And transmitting a wait command for the first cycle if the number of cycles during the defrosting operation is equal to or greater than the simultaneous defrost allowable number.

The air conditioner and the control method thereof according to the present invention limit the number of cycles for performing defrosting operation in the air conditioner having a plurality of cycles to a predetermined number so as to prevent a plurality of cycles exceeding a predetermined number from simultaneously entering the defrosting operation, The defrosting operation of the defrosting device is sequentially performed in a predetermined order, thereby improving the operation efficiency and preventing the cooling and heating operation from being stopped, thereby improving the reliability of the product and the convenience of the user.

1 is a view illustrating an air conditioner according to an embodiment of the present invention.
FIG. 2 is a view showing a plurality of cooling and heating cycles included in the air conditioner shown in FIG. 1. FIG.
FIG. 3 is a diagram showing the relationship between the central controller of FIG. 1 and the main controller and the cycle controller of the air conditioner unit.
4 is a flowchart illustrating a control method of a central controller according to an embodiment of the present invention.
5 is a flowchart showing a control method for an individual air conditioner unit of a central controller according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings for explaining an air conditioner and a control method thereof according to embodiments of the present invention.

FIG. 1 is a view showing an air conditioner according to an embodiment of the present invention, and FIG. 2 is a view showing a plurality of air conditioning cycles included in the air conditioner shown in FIG.

An air conditioner according to an embodiment of the present invention is divided into a cooling unit that cools water using a refrigerant cycle and an air conditioning unit that cools the interior of the building using water cooled in the cooler.

Referring to Figs. 1 and 2, a plurality of air conditioner units in which a plurality of air conditioning cycles are modularized are provided, and a plurality of units 101 to 103 are connected to the central controller 1.

Each of the air conditioner units includes a plurality of compressors and a plurality of heat exchangers as coolers and is connected to each of the plurality of air conditioning units.

Each compressor and heat exchanger is connected to at least one air conditioning unit to form one cycle. The configuration of these cycles is modular and can operate independently of each other and can be added or removed depending on the size of the load.

The air conditioning unit uses the water cooled in the chiller to cool, heat, ventilate, dehumidify, or humidify the interior of the building. The air conditioning unit comprises: an AHU (air handling unit) for mixing indoor air circulated in the room and fresh outdoor air and performing heat exchange with water cooled in the cooler; an air handling unit (AHU) And a fan coil unit (FCU) for circulation. The air conditioning unit and the cooler are connected to an inlet pipe and an outlet pipe through which water circulates.

The condenser includes a compressor for compressing the refrigerant, a condenser for condensing the refrigerant compressed in the compressor, an expansion mechanism for expanding the refrigerant condensed in the condenser, an evaporator for evaporating the refrigerant expanded in the expansion mechanism by heat exchange with water, An inlet pipe through which water flows into the evaporator, and an outlet pipe through which water flows out from the evaporator.

The compressor compresses the refrigerant. Various types of compressors such as a reciprocating type, a rotary type, and a scroll type can be used as the compressor, and the present embodiment is a scroll type compressor. The scroll compressor (120) has a motor therein to rotate the scroll to compress the refrigerant.

The compressor compresses the refrigerant to increase the pressure of the refrigerant. The compressor can change the pressure of the refrigerant compressed and discharged by varying the operation speed. The compressor discharges refrigerant at a higher pressure when operating at a lower speed than at a higher speed. The range of the operating speed is determined by the performance of the compressor. The compressor is connected to the suction pipe and the discharge pipe, compresses the refrigerant sucked through the suction pipe, and discharges the refrigerant to the discharge pipe.

The condenser is connected to the discharge pipe and is compressed in the compressor to condense the refrigerant discharged to the discharge pipe. The condenser cools the refrigerant by exchanging the refrigerant with the fluid such as cooling water or outdoor air.

When the condenser exchanges heat between the refrigerant and the cooling water, it may be formed of a cooling tower (not shown) and a water-cooled heat exchanger that is connected to the cooling water flow path and heat-exchanges the cooling water circulated to the cooling tower and the refrigerant. When the condenser exchanges heat between the refrigerant and outdoor air, it may be formed as an air-cooled heat exchanger in which outdoor air blown by the blower exchanges heat with the refrigerant.

The condenser is connected to the condensing pipe so that the refrigerant condensed in the condenser flows to the expansion mechanism. The expansion mechanism is connected to the condensing pipe to expand the condensed refrigerant in the condenser. The expansion mechanism 140 may be a capillary tube for expanding the refrigerant or electronic expansion valves (EEV). The expansion mechanism expands the refrigerant to lower the pressure of the refrigerant. The expansion mechanism is connected to the expansion pipe so that the refrigerant expanded in the expansion mechanism flows to the evaporator.

The evaporator is connected to the expansion pipe to condense the refrigerant expanded in the expansion mechanism by heat exchange with water. The evaporator cools the water circulating in the air conditioning unit by exchanging heat with the refrigerant. Water flows into the evaporator from the air conditioning unit through the water inlet pipe, and water flows out to the air conditioning unit through the water outlet pipe 162.

The evaporator may be a shell-and-tube heat exchanger comprising a shell through which refrigerant passes and a tube through which water passes, or a plate-type heat exchanger in which a channel through which a refrigerant passes and a channel through which water passes is formed between plate- have.

The evaporator is connected to the suction pipe, and the refrigerant evaporated in the evaporator is sucked into the compressor. The suction pipe connects the evaporator and the compressor, and the suction pipe is provided with a suction pipe pressure sensor for measuring the evaporation pressure which is the pressure of the refrigerant flowing through the suction pipe. The suction pipe pressure sensor measures the pressure of the refrigerant vaporized in the evaporator, that is, the pressure of the refrigerant sucked into the compressor. The suction pipe may be provided with a suction pipe temperature sensor for measuring the temperature of the refrigerant flowing through the suction pipe. The suction pipe temperature sensor measures the temperature of the refrigerant vaporized in the evaporator, that is, the temperature of the refrigerant sucked into the compressor.

Water is introduced from the air conditioning unit into the evaporator in the intake pipe. In the inlet piping, the air that is circulated in the room through the air conditioning unit flows into the evaporator. Water flowing into the evaporator through the intake pipe is cooled by heat exchange with the refrigerant. The inlet pipe is provided with an inlet pipe temperature sensor for measuring the inlet temperature, which is the temperature of the water flowing through the inlet pipe. The inlet pipe temperature sensor measures the inlet water temperature of the water flowing into the evaporator from the air conditioning unit.

Water is discharged from the evaporator to the air conditioning unit in the outflow pipe. The outflow pipe exchanges heat with the refrigerant in the evaporator, and the cooled water flows out to the air conditioning unit. Water flowing out to the air conditioning unit through the outflow pipe cools the room. The outflow pipe is provided with an outflow pipe temperature sensor for measuring the outflow temperature, which is the temperature of water flowing through the outflow pipe. The outflow pipe temperature sensor measures the outflow temperature of the water coming out from the evaporator to the air conditioning unit.

The central controller 1 is connected to a plurality of the air conditioner units 101 to 103 through a predetermined communication network to monitor and control the operation of each of the air conditioner units.

FIG. 3 is a diagram showing the relationship between the central controller of FIG. 1 and the main controller and the cycle controller of the air conditioner unit.

3, each of the air conditioner units includes a main controller 10 for controlling a plurality of independent cycles configured as described above, and a plurality of cycle controllers 100 ).

Each main controller 10 is connected to the central controller 1.

The central controller 1 and the main controller 10 periodically communicate with each other at predetermined time intervals to transmit / receive data to / from the air conditioner unit.

The central controller 1 collects and monitors information on each air conditioner unit, and outputs information of the air conditioner unit. Further, a control command is transmitted to each main controller 10 according to input data.

Each main controller 10 manages data for each cycle based on data received from the cycle controller 100 and transmits the data to the central controller 1.

The main controller 10 includes at least one cycle controller 100, and cycles may be added or reduced depending on the load, and a cycle controller is provided according to the number of cycles. At this time, each cycle controller 100 independently controls the cooling and air conditioning cycles.

The first air conditioner unit 101 includes a cycle configuration in which the first main controller 11, the first to third cycle controllers 111 to 113, and the first to third cycle controllers are connected to operate . The second air conditioner unit 102 includes a cycle configuration in which the second main controller 12, the fourth to sixth cycle controllers 114 to 116, and the fourth to sixth cycle controllers are connected and operated . The third air conditioner unit 103 includes a cycle configuration in which the third main controller 13, the seventh to ninth cycle controllers 117 to 119, and the seventh to ninth cycle controllers are connected to operate .

The first to third main controllers 11 to 13 monitor the operation state of each cycle according to data received from the cycle controller for each cycle included therein, and transmit the control command to each cycle controller according to the setting.

The first to third main controllers 11 to 13 communicate with the central controller 1 to transmit information received from each cycle controller and receive control commands from the central controller 1 so that the cycle is controlled .

The cycle controller 100, that is, the first to ninth cycle controllers 111 to 119, controls the operation of the cooling and air conditioning cycles independently connected according to the setting, independently controls the cooler and the air conditioning unit, And controls the cycle according to the data sensed by the sensor of FIG.

In addition, the cycle controller 100 communicates with any one of the main controllers 10 connected thereto and performs cycle control according to a control command received from the main controller 10 or the central controller 1. [

At this time, the cycle controller 100 determines whether or not the defrosting operation is performed in response to the data detected during operation, requests the defrosting operation to the connected main controller 10, and performs the defrosting operation according to the defrosting operation command. The cycle controller 100 transmits a notification message to the main controller 10 about the start or end of the defrost operation at the start and end of the defrost operation.

The first to third main controllers 11 to 13 transfer input data to each of the plurality of cycle controllers 100 and apply the same setting applied to the plurality of cycles to each cycle controller, So as to complement each other. In particular, the main controller 10 monitors and controls the plurality of cycles so that the defrosting operation is not performed at the same time. At this time, the main controller transmits the defrost operation request of the cycle controller to the central controller, and transmits the defrost operation command of the central controller to the cycle controller.

The central controller 1 monitors the operation of the cycles included in each of the air conditioner units according to data received from the main controller 10 for the plurality of the air conditioner units 101 to 103, Limit the defrosting operation at the same time.

At this time, the central controller 1 not only sets and controls the number of simultaneously defrostable cycles for a plurality of cycles included in the plurality of air conditioner units 101 to 103, but also controls the defrosting operation in each air conditioner unit Thereby preventing the defrosting operation of a plurality of cycles at the same time.

The central controller 1 includes an input unit (not shown) for inputting a command, an output unit (not shown) for outputting the operation state of the cycle, a communication unit (not shown) for communicating with the main controller 10, (Not shown).

Further, the central controller 1 further includes a data section for storing information for a plurality of main controllers and a plurality of cycle controllers, information of a cycle to be received, and data for cycle control.

4 is a flowchart illustrating a control method of a central controller according to an embodiment of the present invention. Referring to FIG. 4, the central controller 1 sets a simultaneous defrost allowable number (S310). The number of simultaneous defrosting cycles is the number of cycles that allow the defrosting operation for a plurality of cycles simultaneously.

The central controller 1 transmits and receives cycle operation information from the first to third main controllers 11 to 13 (S320), outputs information, and monitors the operation state.

When the defrost operation request for a predetermined cycle is received from at least one of the plurality of main controllers (S330), the central controller 1 confirms the number of defrosting cycles based on the operation state for a plurality of cycles (S340 ).

At this time, the defrost operation request is received through the main controller, but is received from the cycle controller included in each air conditioner unit through the main controller.

The central controller 1 compares the number of cycles during the defrosting operation with a preset simultaneous defrost allowable number (S350).

If the number of cycles in the defrosting operation is equal to or greater than the number of simultaneous defrosting operations, the central controller 1 determines whether the number of cycles during defrosting operation is equal to the number of simultaneous defrosting operations (S360) If the number is the same, a wait command is transmitted to the cycle in which the defrost operation is requested (S370).

On the other hand, if the number of defrosting cycles is greater than the number of simultaneous defrosting cycles, an error is output and forced operation control is performed (S380). At this time, the forcible operation control means that the operation is forcibly controlled in response to the number of cycles exceeding a plurality of cycles in the defrosting operation, and can be made to wait. In some cases, the defrosting operation can be restricted so that the cycle in which the current defrosting operation is performed does not exceed the number of simultaneous defrosting operations for the subsequent defrosting operation after the defrosting operation is completed.

The central controller 1 designates the order of performing the defrosting operation for the waiting cycle (S390). At this time, the central controller 1 designates the order in accordance with the defrost operation request order, and when the priority is set in the cycle, the order can be specified according to the priority order.

Further, the central controller 1 changes the order of any one cycle when a plurality of cycles request defrosting operation in one air conditioner unit, so that a plurality of cycles are simultaneously defrosted in one air conditioner unit Prevent the operation from being performed.

On the other hand, if the number of current defrosting cycles is less than the simultaneous defrost allowable number, the central controller 1 transmits a defrosting operation command to the requested cycle (S400).

When at least one of the defrosting cycles completes the defrosting operation (S410), the central controller 1 transmits a defrosting operation command to the waiting cycle according to the specified order (S420).

At this time, the main controller 10 determines whether a defrosting operation cycle in the air conditioner unit exists for the defrost operation request received from the cycle controller 100, and accepts the defrosting operation of the cycle for the defrost operation request Or to limit defrosting operation.

The main controller 10 limits the plurality of cycles at the same time so as to prevent the defrosting operation from being performed. If the defrosting operation is accepted, the main controller 10 transmits a defrosting operation request to the central controller 1 before transmitting the defrosting operation command to the cycle controller When the defrost operation command of the central controller 1 is received, the defrost operation command is transmitted to the cycle controller 100 so that the cycle performs the defrost operation.

5 is a flowchart showing a control method for an individual air conditioner unit of a central controller according to an embodiment of the present invention. 5, when the defrost operation request is received (S450), the central controller 1 confirms the number of defrosting cycles corresponding to the operation state for a plurality of cycles.

At this time, the control unit of the central controller 1 compares the number of cycles currently under defrosting operation with the predetermined number of simultaneous defrosting operations, and determines whether the number of cycles under the current defrosting operation is less than the number of simultaneously defrostable operations.

At this time, if the number of cycles currently under defrosting operation is equal to or greater than the simultaneous defrost allowable number, a wait command is transmitted for the cycle in which defrosting operation is requested (S470).

In response to the waiting cycle after requesting the defrosting operation, the central controller 1 designates a sequence according to the wait (S480). When the defrosting operation is completed during the current defrosting cycle, defrosting operation should be started sequentially in the specified sequence.

At this time, as described above, the central controller 1 designates the order in accordance with the priority order of the request sequence or the cycle with respect to the cycle of waiting without entering the defrosting operation.

When any of the defrosting cycles in the defrosting cycle is completed (S490), the central controller 1 again compares the number of defrosting cycles and the number of simultaneous defrosting cycles (S460).

If the number of defrosting cycles is less than the simultaneous defrost allowable number, the control unit of the central controller 1 collects information from each main controller 10 in a waiting cycle, i.e., a defrosting operation requested cycle (S550).

The central controller 1 judges whether there is a plurality of cycles for defrost operation or defrost operation per one air conditioner unit, according to the information received from the main controller of the air conditioner unit including the cycle S510).

If the other cycle in the air conditioner unit including the cycle for starting the defrosting operation in order is in normal operation and there is no other cycle requesting the defrosting operation, the control unit of the central controller 1 sequentially The defrost operation command is transmitted (S520).

On the other hand, if another cycle is defrosting operation in the air conditioner unit including the cycle requesting the defrost operation, the control unit of the central controller 1 transmits a wait command to the cycle (S530) (S540).

The cycle in which the wait command is received is changed in order. As for the cycle of the next procedure, the defrosting operation command is transmitted after determining whether another cycle is defrosting operation in the same air conditioner unit, as described above.

When a plurality of cycles request defrost operation in the air conditioner unit including the defrost operation request cycle, a control command is transmitted so that defrosting operation is performed in order. In the next cycle, a standby command is transmitted, .

That is, the central controller ensures that a plurality of cycles in one air conditioner unit do not simultaneously perform defrosting operation, even if the number of defrosting cycles is less than the simultaneous defrostable number.

For example, when the defrost operation request is received from the first cycle controller 111 and the second cycle controller 112 for the first cycle and the second cycle of the first air conditioner unit, , And when a defrosting operation request is received from the fourth cycle controller 114 in the fourth cycle of the second air conditioner unit, the sequence of the defrosting operation in the order of the first cycle, the second cycle and the fourth cycle .

However, if the defrosting operation in the second cycle is completed before the defrosting operation in the first cycle is completed after the first cycle starts defrosting operation, the defrosting operation in the second cycle can be started. In this case, The central controller 1 transmits a defrost operation command for the first cycle and a wait command to the second cycle while the defrost operation for the fourth cycle is performed first So that the first cycle and the second cycle are not defrosted at the same time.

In addition, when the third cycle of the first air conditioner unit is performing the defrosting operation, the central controller 1 transmits a standby command for the defrosting operation request of the first cycle and waits for the second cycle, After the command is transmitted, the defrosting operation is performed in preference to the cycle of the second or third air conditioner unit, i.e., the fourth cycle other than the first air conditioner unit.

That is, the central controller 1 can perform a defrosting operation for a plurality of cycles included in a plurality of air conditioner units within the range of the set number of simultaneous defrosting operations, while simultaneously executing a plurality of cycles in one air conditioner unit Limit the defrosting operation.

Therefore, the present invention can prevent the defrosting operation from being performed simultaneously with the defrosting operation by limiting the defrosting operation to a predetermined number or more for a plurality of cycles, The efficiency is improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

1: central controller 10, 11 to 13: main controller
100, 111 to 119: Cycle controller
101 to 103: air conditioner unit

Claims (12)

A plurality of air conditioner units, each of which includes a plurality of cycle controllers for individually controlling independent operating cycles, and a main controller connected to the cycle controller for monitoring and controlling a plurality of cycles; And
And a central controller connected to the plurality of main controllers to receive, monitor, and control data for a plurality of cycles included in the plurality of air conditioner units,
The central controller sets the number of simultaneous defrosting possible for the plurality of cycles and sets the number of simultaneously defrostable cycles for the plurality of cycles in accordance with the defrosting operation request received from each cycle controller connected to the plurality of cycles via the main controller, The defrosting operation is controlled so that the defrosting operation is performed below the permissible number,
Wherein the defrosting operation is performed so that the defrosting operation is performed for the plurality of cycles at a time equal to or less than the simultaneously defrostable number so that a plurality of cycles in one air conditioner unit are not defrosted at the same time. The method according to claim 1,
Wherein when the defrost operation request is received from any one of the plurality of cycle controllers, the central controller compares the number of cycles in the current defrosting operation with the number of simultaneous defrost operations, Transmits a defrost operation command via the connected main controller, and transmits a standby command when the number of defrosting cycles is equal to or greater than the simultaneous defrost allowable number. 3. The method of claim 2,
Wherein the central controller controls the defrosting operation to be sequentially performed in accordance with at least one of a defrosting operation request order and a cycle priority order when a plurality of waiting cycles are present. delete The method according to claim 1,
Wherein the central controller is configured to determine whether any of the other cycles of the air conditioner unit including the cycle requesting the defrost operation is in the defrosting operation and the case where the plurality of cycles requested the defrost operation in the air conditioner unit The order is changed in the case of the air conditioner. A control method of a central controller connected to a plurality of air conditioner units including a plurality of cycles,
Comparing the number of cycles currently under defrosting operation with the number of simultaneous defrosting operations when a defrost operation request is received from a first cycle controller controlling a first one of the plurality of cycles;
Transmitting a defrost operation command for the first cycle to the first cycle controller if the number of cycles during the defrosting operation is less than the simultaneous defrost allowable number;
Transmitting a wait command for the first cycle if the number of cycles during the defrosting operation is equal to or greater than the simultaneous defrost allowable number;
When defrosting operation of any one of the first cycle atmosphere is completed,
Receiving information of a first air conditioner unit including the first cycle from a first main controller connected to the first air conditioner; And
Determining whether the defrosting operation of the first air conditioner unit is determined by determining whether defrosting operation is performed in another cycle included in the first air conditioner unit,
Wherein the defrost operation command and the standby command are transmitted to the first cycle controller through the one main controller. delete The method according to claim 6,
Further comprising the step of specifying an order corresponding to at least one of a defrost operation request order and a priority for a cycle if the number of waiting cycles is plural. delete The method according to claim 6,
Wherein if there is another cycle in the defrosting operation in the first air conditioner unit, a standby command is transmitted to the first cycle controller in the first cycle,
Wherein when the first air conditioner unit does not have another cycle for defrosting operation, a defrost operation command is transmitted to the first cycle. The method according to claim 6,
Further comprising transmitting a defrost operation command to a second cycle controller in a second cycle, which is the next order of the first cycle, if there is another cycle in the defrosting operation in the first air conditioner unit Way. 9. The method of claim 8,
When a defrost operation request is received from a third cycle controller in a third cycle, which is another cycle of the first air conditioner unit including the first cycle, in the first cycle atmosphere, the first cycle and the third cycle Further comprising changing the order of the third cycle so that the defrosting operation is not performed at the same time.

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