KR100953193B1 - Control method of multi type air conditioner - Google Patents

Abstract

The present invention provides a method of operating a multi-type air conditioner in which a plurality of indoor units having an indoor expansion valve and an indoor heat exchanger are provided in an outdoor unit having a compressor, an air / heating switching valve, an outdoor heat exchanger, and an outdoor expansion valve. A sensing step of detecting an indoor unit in which a refrigerant supply is insufficient among a plurality of indoor units that are driving during operation of the vehicle; When the indoor unit lacking the refrigerant supply is detected by the detecting step, a cooperative step of lowering the opening degree of the indoor expansion valve of the other indoor unit other than the indoor unit in which the refrigerant supply is insufficient may be generated in a specific indoor unit during heating operation. There is an advantage that the lack of possible heating performance is eliminated.

Air conditioner, indoor unit, indoor heat exchanger, indoor expansion valve, cooperative control

Description

Control method of multi type air conditioner

The present invention relates to a method of operating a multi-type air conditioner, and more particularly, to a method of operating a multi-type air conditioner to induce a refrigerant to an indoor unit in which a refrigerant is insufficiently supplied among a plurality of indoor units to solve a lack of heating performance of some indoor units. .

In general, an air conditioner is a device for cooling or heating an indoor room using a refrigeration cycle device including a compressor, a condenser, an expansion device, and an evaporator. Recently, a multi-type air conditioner connecting a plurality of indoor units to one outdoor unit is gradually increasing. .

The multi-type air conditioner includes an outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, and an outdoor expansion valve, a plurality of indoor units including an indoor expansion valve and an indoor heat exchanger, and the outdoor unit and the indoor unit to transport refrigerant between the outdoor unit and the indoor unit. It is configured to include a refrigerant pipe for connecting.

The multi-type air conditioner does not supply enough refrigerant to the indoor unit (ie, the branch branch indoor unit of the refrigerant pipe) farthest from the outdoor unit among the plurality of indoor units, and the heating capability of the indoor unit farthest from the outdoor unit in heating operation. There is a problem that can be low.

On the other hand, Korean Patent Laid-Open Publication No. 10-2007-0030590 discloses a method of operating a multi-type air conditioner that opens-controls an outdoor expansion valve when the flow rate supply to the indoor unit in operation is insufficient.

In the method of operating the multi-type air conditioner, it is determined whether the compressor compresses the liquid, determines whether the flow rate supply to the indoor unit in operation among the plurality of indoor units is insufficient, and it is determined that the liquid supply is not compressed. If it is determined that the outdoor expansion valve is controlled to open the flow rate to a plurality of indoor units quickly.

However, the operation method of the multi-type air conditioner disclosed in Korean Patent Laid-Open Publication No. 10-2007-0030590 increases the amount of refrigerant flowing from the outdoor unit to the indoor unit by determining whether the flow rate is insufficient for the indoor unit, thereby increasing the amount of refrigerant. There is a problem that only the indoor unit is concentrated and the refrigerant may not be sufficiently supplied to the indoor unit that is farthest from the outdoor unit.

The present invention has been made to solve the above problems of the prior art, an object of the present invention is to provide a method of operating a multi-type air conditioner that can solve the lack of heating performance of the indoor unit that is substantially supplied with insufficient refrigerant.

Another object of the present invention is to provide a method of operating a reliable multi-type air conditioner.

The present invention for solving the above problems is a method of operating a multi-type air conditioner having a plurality of indoor units having an indoor expansion valve and an indoor heat exchanger, the outdoor unit having a compressor, an air / heating switching valve, an outdoor heat exchanger and an outdoor expansion valve. The method of claim 1, further comprising: detecting an indoor unit having insufficient refrigerant supply among a plurality of indoor units in operation when the multi-type air conditioner is in operation; If the indoor unit is insufficient in the refrigerant supply is detected by the sensing step, and the cooperative step of lowering the opening degree of the indoor expansion valve of the other indoor unit other than the indoor unit is detected as insufficient refrigerant supply by a set value.

The operation method of the air conditioner repeats the sensing step and the cooperative step at a time interval for cooperative repetition after the cooperative step, and further decreases the opening degree of the indoor expansion valve by a predetermined value when the cooperative step is repeated.

The detecting step detects an indoor unit having an overcooling value exceeding a set value and an opening degree of the indoor expansion valve being a set opening range as an indoor unit having insufficient refrigerant supply.

The present invention provides a method of operating a multi-type air conditioner in which a plurality of indoor units having an indoor expansion valve and an indoor heat exchanger are provided in an outdoor unit having a compressor, an air / heating switching valve, an outdoor heat exchanger, and an outdoor expansion valve. During the heating operation, the sensor detects the overcooling of each indoor unit in the heating operation and the opening degree of the indoor expansion valve, and detects the indoor unit whose subcooling exceeds the set value and the opening degree of the indoor expansion valve is the setting opening range as an indoor unit with insufficient supply of refrigerant. And an indoor expansion valve cooperating step of lowering the opening degree of the indoor expansion valve of the other indoor unit by the set value other than the indoor unit detected as lack of the refrigerant supply; After the indoor expansion valve cooperating step detects the pipe temperature of each indoor unit of the heating operation, if the pipe temperature is less than the set temperature, the indoor unit having a difference between the average temperature and the pipe temperature of the indoor unit of the heating operation is more than the set value, the outdoor And an outdoor expansion valve cooperative step of fully opening the expansion valve.

The indoor expansion valve cooperative step is repeatedly performed at a cooperative repetition set time interval, and when the opening degree of the indoor expansion valve of the other indoor unit decreases, the opening degree of the indoor expansion valve of the other indoor unit is further lowered by a set value.

The indoor expansion valve coordinating step is performed when the indoor cooperative control setting time elapses after the start of the heating operation, and the outdoor expansion valve coordinating step is performed when the outdoor cooperative control setting time is longer than the indoor cooperative control setting time after the start of the heating operation. Is carried out.

The present invention provides a method of operating a multi-type air conditioner in which a plurality of indoor units having an indoor expansion valve and an indoor heat exchanger are provided in an outdoor unit having a compressor, an air / heating switching valve, an outdoor heat exchanger, and an outdoor expansion valve. A sensing step of detecting a supercooling degree of each of the indoor units in the heating operation and an opening degree of the indoor expansion valve and a pipe temperature during the heating operation of the heating unit; As a result of the detection in the sensing step, the supercooling is over the set value, the opening degree of the indoor expansion valve is the set opening range, the piping temperature is less than the set temperature, the difference between the pipe temperature average temperature and the pipe temperature of the indoor unit during heating operation is more than the set value. And detecting an indoor unit as an indoor unit having insufficient refrigerant supply, lowering the opening degree of the indoor expansion valve of the other indoor unit other than the indoor unit detected as having insufficient refrigerant supply, by a set value, and cooperating a pull-off of the outdoor expansion valve.

The operation method of the multi-type air conditioner according to the present invention configured as described above detects an indoor unit in which refrigerant is insufficiently supplied during heating operation, and lowers the opening degree of the indoor expansion valve of another indoor unit by a set value to reduce the refrigerant supplied from the outdoor unit. Since the refrigerant is introduced to the indoor unit that is supplied inadequately, there is an advantage that the lack of heating performance that may occur in a specific indoor unit during heating operation is eliminated.

  In addition, the operation method of the multi-type air conditioner according to the present invention continuously detects an indoor unit supplied with insufficient refrigerant and further lowers the opening degree of the indoor expansion valve of the other indoor unit by a set value, thereby improving reliability and improving other indoor units. There is an advantage that can prevent the refrigerant shortage of the other indoor unit that may occur when the indoor expansion valve of the close at once is excessively closed.

In addition, the operation method of the multi-type air conditioner according to the present invention detects the shortage of the refrigerant by the overcooling of the indoor unit in operation, so that the shortage of the refrigerant can be more accurately detected, and there is an advantage of high reliability of the refrigerant shortage detection.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic configuration diagram of a multi-type air conditioner to which a driving method of a multi-type air conditioner according to the present invention is applied.

 The multi-type air conditioner illustrated in FIG. 1 is a refrigerant pipe connecting a plurality of indoor units 1 to 4, an outdoor unit 21, a plurality of indoor units 1 to 4, and an outdoor unit 21 installed inside a building ( 30) 40.

Each of the indoor units 1 to 4 includes an indoor heat exchanger 51 for exchanging refrigerant and indoor air, an indoor blower 52 installed near the indoor heat exchanger 51 to circulate indoor air, and the indoor air when cooling. A linear expansion valve (LEV) 54 is provided to expand the refrigerant flowing into the heat exchanger 51 to control the supercooling degree of the indoor units 1 to 4.

In the indoor units 1 to 4, refrigerant pipes 30 and 40 are connected in parallel.

The outdoor unit 21 includes an accumulator 61 through which only gaseous refrigerant of the refrigerants supplied from the indoor units 1 to 4 passes, and compressors 62 and 63 for receiving and compressing the gaseous refrigerant passing through the accumulator 61; In addition, the cooling / heating switching valve 65 which is connected to the compressors 62 and 63 and selects a flow path of the compressed refrigerant, and the refrigerant supplied from the cooling / heating switching valve 65 to exchange heat with the outdoor air. And an outdoor heat exchanger (70) and an outdoor blower (72) installed near the outdoor heat exchanger (70) for blowing outdoor air to the outdoor heat exchanger (70).

In addition, an outdoor expansion valve (74, LEV: Linear expansion) for controlling the compressor superheat by expanding the refrigerant during heating in the refrigerant pipe (30) for guiding the refrigerant discharged from the outdoor heat exchanger (70) to the indoor units (1 to 4). valve), a bypass flow path 75 for bypassing the outdoor expansion valve 74, and a check valve 76 for blocking the bypass flow path 75 when the heating path 75 is heated.

Here, the outdoor expansion valve 74 is fully open during cooling to pass through the refrigerant condensed in the outdoor heat exchanger 70 without expanding, but when heated, the outdoor expansion valve 74 is opened to a predetermined size and condensed in the indoor heat exchanger 51. Before expanding to the outdoor heat exchanger (70) to the liquid in the spray state.

In FIG. 1, reference numeral 120 denotes a compressor 62, 63, an air / heating switching valve 65, an outdoor expansion valve 74, an indoor expansion valve 54, and the like, while communicating with the indoor units 1 to 4. It is a control unit for controlling.

Reference numeral 122 shown in FIG. 1 denotes an indoor heat exchanger temperature sensor for measuring the temperature of the indoor heat exchanger 51 of the indoor units 1 to 4.

Reference numeral 124 shown in Figure 1 is an indoor pipe temperature sensor for measuring the outlet temperature of the indoor heat exchanger 51 during the indoor piping, especially heating operation of the indoor unit (1-4).

126 illustrated in FIG. 1 is a connection line connecting the indoor units 1 to 4 and the outdoor unit 21 to transmit data between the indoor units 1 to 4 and the outdoor unit 21.

Hereinafter, a method of operating a multi-type air conditioner according to the present invention will be described in more detail with reference to FIG. 2.

2 is a flowchart illustrating an embodiment of a method of operating a multi-type air conditioner according to the present invention.

 In the operation method of the multi-type air conditioner according to the present embodiment, when a preset time elapses after the start of heating operation during the heating operation of the multi-type air conditioner, the indoor unit in which the refrigerant supply is insufficient among the plurality of indoor units 1 to 4 in operation is insufficient. A detection step of detecting the signal is performed. (S1) (S2) (S3) (S4)

Here, the set time (hereinafter referred to as the set up time for indoor cooperative control) is a time for which the multi-type air conditioner has been operated to the extent that the indoor unit having insufficient refrigerant supply is detected, and is set by an experiment or the like.

Describing the sensing step in detail, the method of operating the multi-type air conditioner according to the present embodiment includes, when the indoor cooperative control setting time elapses after the heating operation is started, each of the indoor units 1 to 4 under operation and the indoor cooling. The opening degree of the expansion valve 54 is sensed. (S1) (S2) (S3)

In the operation method of the multi-type air conditioner according to the present embodiment, an indoor unit having a detected overcooling degree exceeding a set value and an opening degree of the indoor expansion valve 54 being a set opening range is detected as an indoor unit having insufficient refrigerant supply. S4)

Here, the subcooling is a difference between the liquid pipe temperature (ie, the indoor heat exchanger pipe temperature) and the condenser outlet temperature (ie, the outlet temperature of the indoor heat exchanger) during the heating operation, and passes through the indoor expansion valve (54) when the subcooling increases. The pressure drop of the refrigerant increases, and the pressure drop of the refrigerant passing through the indoor expansion valve 54 decreases when the degree of subcooling decreases.

That is, when the opening degree of the indoor expansion valve 54 is lowered, the pressure drop of the refrigerant passing through the indoor expansion valve 54 is increased, the supercooling degree is increased, and the flow rate is decreased. On the other hand, when the opening degree of the indoor expansion valve 54 is increased, the pressure drop of the refrigerant passing through the indoor expansion valve 54 is reduced, the supercooling degree is lowered, and the flow rate is increased.

Here, the set opening range is an opening range through which the indoor expansion valve passes the refrigerant smoothly, and is set by experiment or the like.

On the other hand, according to the principle described above, the set value and the set opening range when the indoor unit lacking the refrigerant among the plurality of indoor units (1 to 4) is calculated through experiments and stored in the control unit 120, this embodiment The operation method of the multi-type air conditioner according to the present invention includes an indoor heat exchanger temperature sensor 122 of each indoor unit and a supercooling degree of each of the indoor units 1 to 4 in operation by receiving temperature values of the indoor piping temperature sensor 124. From the opening degree of the indoor expansion valve 54, it detects the indoor unit that the refrigerant supply is insufficient.

In the operation method of the multi-type air conditioner according to the present embodiment, when the indoor unit 4 having insufficient refrigerant supply is detected, other than the indoor unit 4 detected by the refrigerant shortage among the plurality of indoor units 1 to 4 in operation. A cooperative step of lowering the opening degree of the indoor expansion valve 54 of the indoor units 1 to 3 by a set value is performed. (S5)

Here, it is preferable that the set value is set to such an extent that the refrigerant flow of the other indoor units 1 to 3 does not change rapidly while eliminating the refrigerant shortage of the indoor unit 4 having insufficient refrigerant.

When the opening degree of the indoor expansion valve 54 of the other indoor units 1 to 3 other than the indoor unit 4 detected as the refrigerant shortage is lowered by the set value, the amount of the refrigerant supplied to the other indoor units 1 to 3 is reduced. The amount of the coolant supplied to the indoor unit 4 detected by the shortage of the coolant is relatively increased.

On the other hand, the operating method of the multi-type air conditioner according to the present embodiment, the opening degree of the indoor expansion valve 54 of the other indoor units (1 to 3) other than the indoor unit (4) detected by the lack of refrigerant as described above by the set value. After the lowering, the sensing steps S3 and S4 and the cooperative step S5 are repeated at a set time interval (hereinafter, referred to as a cooperative repeat setting time).

That is, the operation method of the multi-type air conditioner according to the present embodiment not only adjusts the amount of refrigerant once, but also detects whether the refrigerant is sufficiently supplied to the indoor unit 4 which is insufficient in the refrigerant among the indoor units in operation.

In the method of operating the multi-type air conditioner according to the present embodiment, when the degree of supercooling of the indoor unit 4 detected as the refrigerant shortage is reduced by adjusting the opening degree of the first indoor expansion valve 54, that is, below the set value, that is, When the lack of refrigerant is eliminated, the current state is maintained.

On the other hand, in the method of operating the multi-type air conditioner according to the present embodiment, when the degree of opening of the first indoor expansion valve 54 is adjusted, the supercooling degree of the indoor unit 4 which has been detected as lack of refrigerant is not reduced, that is, If the lack of refrigerant is not resolved, repeat the cooperative step (S5).

The operation method of the multi-type air conditioner according to the present embodiment further lowers the opening degree of the indoor expansion valve 54 of the other indoor units 1 to 3 when the cooperative step S5 is repeated by the set values as described above.

In the multi-type air conditioner, when the sensing steps S3 and S4 and the cooperative step S5 are repeated, the supercooling degree of the indoor unit 4, which has been detected as lack of refrigerant, is gradually lowered below a set value, and the indoor unit is in operation. Some of the lack of heating performance is eliminated.

3 is a flowchart illustrating another embodiment of a method of operating a multi-type air conditioner according to the present invention.

The operation method of the multi-type air conditioner according to the present embodiment is the same as the operation method of the multi-type air conditioner according to the embodiment of the present invention, the detection step (S1) (S2) (S3) (S4) and the cooperative step (S5). When the preset time elapses after the heating operation starts, the indoor heat exchanger pipe temperature (that is, condensation temperature) of the plurality of indoor units 1 to 4 in operation is sensed. (S6) (S7)

Here, the setting time (hereinafter, referred to as the outdoor cooperative control setting time) is a time when the multi-type air conditioner is operated to detect a shortage of refrigerant supplied from the outdoor unit to the indoor unit, and the indoor cooperative control setting time according to the embodiment of the present invention. Is set longer.

In the operation method of the multi-type air conditioner according to the present embodiment, when the outdoor cooperative control setting time elapses after starting the heating operation, the pipe temperature of the indoor unit under operation is less than the set pipe temperature, and the average temperature of the pipe temperature and the pipe If the temperature difference is greater than or equal to the set value, it is determined that the amount of refrigerant supplied from the outdoor unit to the indoor unit is insufficient, and the outdoor expansion valve 74 is fully opened. (S8) (S9)

When the outdoor expansion valve 74 is fully open as described above, the refrigerant passing through the outdoor unit, in particular, the outdoor heat exchanger 70, is increased in the amount of the refrigerant moved to the indoor unit in operation, in particular the indoor heat exchanger 51, and the indoor units 1 to 4 are increased. Some of the lack of heating performance is eliminated.

That is, in the method of operating the air conditioner according to the present embodiment, when the indoor cooperative control setting time elapses after the heating operation is started, the indoor expansion of the other indoor units other than the indoor unit detected as lack of the refrigerant supply as in the embodiment of the present invention Implement the indoor expansion valve coordination step to lower the opening degree of the valve by the set value, and primarily eliminate the lack of heating performance of some of the indoor units by reducing the amount of refrigerant flowing to other indoor units and increasing the amount of refrigerant flowing to the indoor unit that lacks refrigerant supply. After the heating operation starts, the outdoor cooperative control setting time has elapsed, and the heating performance of some of the indoor units is increased by performing an outdoor expansion valve cooperative step of fully opening the outdoor expansion valve 74 to increase the amount of refrigerant supplied to the indoor unit from the outdoor unit. Eliminate the shortage secondly, supply the refrigerant insufficiently by the above-mentioned several times the refrigerant induction By Southern indoor unit is to be enough refrigerant is supplied, the lack of heating performance, some of the indoor units are all eliminated.

On the other hand, the operation method of the air conditioner according to the present invention, the opening degree of the indoor expansion valve is reduced only before the outdoor cooperative control setting time, it is also possible not to be carried out after the outdoor cooperative control setting time, It is, of course, also possible that the reduction of the opening degree can be carried out with the passage of the outdoor cooperative control set time and the outdoor expansion valve full opening.

4 is a flowchart illustrating another embodiment of a method of operating a multi-type air conditioner according to the present invention.

In the operation method of the multi-type air conditioner according to the present embodiment, when a preset time elapses after the start of heating operation during the heating operation of the multi-type air conditioner, the indoor unit in which the refrigerant supply is insufficient among the plurality of indoor units 1 to 4 in operation is insufficient. A detection step of detecting the signal is performed. (S1) (S2 ') (S3')

Here, the set time is a time when the multi-type air conditioner is operated to detect an indoor unit having insufficient refrigerant supply and to detect a shortage of refrigerant supplied from the outdoor unit to the indoor unit, and is set by an experiment or the like.

Describing the sensing step in detail, the operation method of the multi-type air conditioner according to the present embodiment includes, when a set time elapses after the heating operation is started, each of the indoor units 1 to 4 under operation and the indoor expansion valve ( 54) and the pipe temperature of the indoor heat exchanger 51 (S2 ') (S3').

And, in the operation method of the multi-type air conditioner according to the present embodiment, the supercooling degree exceeds the set value, the opening degree of the indoor expansion valve 54 is the set opening range, the piping temperature is below the set piping temperature, The indoor unit whose difference between the average temperature and the pipe temperature is the set value is detected as the indoor unit having insufficient refrigerant supply (S4 ′).

In the operation method of the multi-type air conditioner according to the present embodiment, when the indoor unit 4 having insufficient refrigerant supply is detected, other than the indoor unit 4 detected by the refrigerant shortage among the plurality of indoor units 1 to 4 in operation. A cooperative step of lowering the opening degree of the indoor expansion valve 54 of the indoor units 1 to 3 by a set value is performed. (S5)

In the cooperative step S5, the opening degree of the indoor expansion valve 54 of the other indoor unit may be lowered by a set value. The cooperative step S5 may be lowered by the set value as described above and the full open of the outdoor expansion valve 74 may be performed. The opening degree of the expansion valve 54 is lowered by a set value and the outdoor expansion valve 74 is fully opened.

As described above, when the opening degree of the indoor expansion valve 54 of the other indoor unit is lowered by a set value and the outdoor expansion valve 74 is fully opened, the amount of refrigerant supplied to the indoor unit operating from the outdoor unit is increased, and the indoor unit is supplied to the indoor unit in operation. The supply of the refrigerant to the indoor unit, which lacks the refrigerant supply among the used refrigerants, is increased.

On the other hand, the operating method of the multi-type air conditioner according to the present embodiment, the opening degree of the indoor expansion valve 54 of the other indoor units (1 to 3) other than the indoor unit (4) detected by the lack of refrigerant as described above by the set value. After lowering and fully opening the outdoor expansion valve 74, the sensing steps S3 'and S4' and the cooperative step S5 'are repeated at set intervals (hereinafter, referred to as cooperative repetition set time).

When the cooperative step is repeated as described above, the opening degree of the indoor expansion valve 54 of the other indoor units 1 to 3 is further lowered by the set values as described above.

In the multi-type air conditioner, the indoor unit 4, which has been detected as lack of refrigerant, is rapidly reduced to less than the set value when the sensing steps S3 'and S4' and the cooperative step S5 'are repeated. The lack of heating performance of some of the indoor units in operation is resolved more quickly.

1 is a schematic configuration diagram of a multi-type air conditioner to which a driving method of a multi-type air conditioner according to the present invention is applied;

2 is a flowchart showing an embodiment of a method of operating a multi-type air conditioner according to the present invention;

3 is a flow chart showing another embodiment of a method of operating a multi-type air conditioner according to the present invention;

4 is a flowchart illustrating another embodiment of a method of operating a multi-type air conditioner according to the present invention.

<Explanation of symbols on main parts of the drawings>

1,2,3,4: Indoor unit 21: Outdoor unit

30, 40: refrigerant piping 51: indoor heat exchanger

54: indoor expansion valve 62, 63: compressor

65; Cooling / heating switching valve 70; Outdoor heat exchanger

74: outdoor expansion valve 120: control unit

122: indoor heat exchanger temperature sensor 124: indoor piping temperature sensor

Claims (7)

In a method of operating a multi-type air conditioner in which a compressor, a cooling / heating switching valve, an outdoor heat exchanger and an outdoor expansion valve are provided, and a plurality of indoor units having an indoor expansion valve and an indoor heat exchanger are connected. A sensing step of detecting an indoor unit having insufficient refrigerant supply among a plurality of indoor units in operation when the multi-type air conditioner is in operation; And a cooperative step of lowering the opening degree of the indoor expansion valve of the other indoor unit other than the indoor unit in which the refrigerant supply is insufficient due to the detection step, by a predetermined value. The method of claim 1, The operation method of the air conditioner repeats the detecting step and the cooperative step at a time interval for cooperative repetition after the cooperative step, Operating method of the multi-type air conditioner to further reduce the opening degree of the indoor expansion valve by a set value at the time of repeating the cooperative step. The method according to claim 1 or 2, The detecting step is a method of operating a multi-type air conditioner for detecting an indoor unit having a supercooled value exceeds a set value and the degree of opening of the indoor expansion valve is a set opening range as a lack of refrigerant supply. In the operating method of a multi-type air conditioner in which a plurality of indoor units having an indoor expansion valve and an indoor heat exchanger are provided in an outdoor unit provided with a compressor, a cooling / heating switching valve, an outdoor heat exchanger, and an outdoor expansion valve. During the heating operation of the multi-type air conditioner, by detecting the supercooling of each indoor unit in the heating operation and the degree of opening of the indoor expansion valve, supplying the refrigerant to the indoor unit in which the subcooling exceeds the set value and the opening degree of the indoor expansion valve is the set opening range. An indoor expansion valve co-operation step of detecting a lacking indoor unit and lowering the opening degree of the indoor expansion valve of the other indoor unit other than the indoor unit detected by the insufficient supply of refrigerant by a set value; After the indoor expansion valve coordination step, by detecting the pipe temperature of each of the indoor unit of the heating operation, if the pipe temperature is less than the set temperature, the indoor unit having a difference between the average temperature and the piping temperature of the indoor unit of the heating operation is more than the set value, the outdoor A method of operating a multi-type air conditioner including an outdoor expansion valve cooperative step of fully opening an expansion valve. The method of claim 4, wherein The indoor expansion valve coordination step is repeated at a set time interval of cooperative repetition, When the opening degree of the indoor expansion valve of the other indoor unit is reduced, the operation method of the multi-type air conditioner further lowers the opening degree of the indoor expansion valve of the other indoor unit by a set value. The method of claim 4, wherein The indoor expansion valve coordinating step is carried out when the indoor cooperative control setting time elapses after the start of the heating operation, The outdoor expansion valve cooperating step is a method of operating a multi-type air conditioner is performed when the set time of the outdoor cooperative control longer than the set time of the indoor cooperative control after the start of the heating operation. In the operating method of a multi-type air conditioner in which a plurality of indoor units having an indoor expansion valve and an indoor heat exchanger are provided in an outdoor unit provided with a compressor, a cooling / heating switching valve, an outdoor heat exchanger, and an outdoor expansion valve.  A sensing step of sensing a supercooling degree of each indoor unit during heating operation and an opening degree of an indoor expansion valve and a pipe temperature during a heating operation of the multi-type air conditioner; As a result of the detection in the sensing step, the supercooling is over the set value, the opening degree of the indoor expansion valve is the set opening range, the piping temperature is less than the set temperature, the difference between the pipe temperature average temperature and the pipe temperature of the indoor unit during heating operation is more than the set value. A multi-type air conditioner comprising a cooperative step of detecting an indoor unit as an indoor unit having insufficient refrigerant supply, lowering the opening degree of the indoor expansion valve of another indoor unit other than the indoor unit detected as lack of refrigerant supply by a set value, and pulling off the outdoor expansion valve. How to drive a flag.

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