KR20090107310A - Air conditioner - Google Patents

Abstract

PURPOSE: A multi-type air conditioner and a heating operation coordination control method are provided to prevent generation of the noise in the coordination control by coordination-controlling the indoor units by considering the operation rate of plural indoor units and the outlet pipe temperature of an operator indoor unit. CONSTITUTION: A multi-type air conditioner is composed of an outdoor unit, plural indoor units, and a control unit(85). The outdoor unit includes compressors(62,63), a cooling/heating switching valve(72), an outdoor expanding unit(74), and an indoor heat exchanger. The plural indoor units are connected with refrigerant pipes and include an indoor heat exchanger, a indoor expand valves(14,24,34,44), and an outlet pipe temperature sensor. The control unit coordination-controls an indoor expending valve of an operator indoor unit if the operation rate of the plural indoor units is more than set value and the outlet pipe temperature of the operator indoor unit is higher than the base temperature.

Description

Multi air conditioner and its heating operation cooperative control method {Air conditioner}

 The present invention relates to a multi-type air conditioner and a heating operation cooperative control method, and in particular, a multi-type air conditioner for cooperatively controlling an electronic expansion valve of an indoor unit operated in consideration of the operation rate of a plurality of indoor units and the outlet piping temperature of the indoor unit. And a heating operation cooperative control method thereof.

 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-mentioned problems of the prior art, it is possible to solve the substantial heating medicine that can be generated in a specific indoor unit during heating operation, the operation rate of the plurality of indoor units and the outlet piping temperature of the indoor unit that is operating It is an object of the present invention to provide a multi-type air conditioner and a heating operation cooperative control method which can prevent noise generated during cooperative control because of cooperative control of the indoor unit.

The multi-type air conditioner according to the present invention for solving the above problems is an outdoor unit including a compressor, a cooling / heating switching valve, an outdoor expansion mechanism, and an indoor heat exchanger, connected to the outdoor unit and a refrigerant pipe, and an indoor heat exchanger and an indoor expansion. A plurality of indoor units including a valve and including an outlet pipe temperature sensor for sensing an outlet pipe temperature of an indoor heat exchanger during a heating operation; And a control unit for cooperatively controlling the indoor expansion valve of the indoor unit when the operation rate of the plurality of indoor units is greater than or equal to a set value and the outlet pipe temperature of all indoor units that are the operation is higher than the reference temperature during the heating operation.

The heating operation cooperative control method for a multi-type air conditioner according to the present invention includes: an operation rate detecting step of detecting an operation rate of an indoor unit which is an operation among the plurality of indoor units during heating operation of a multi-type air conditioner in which a plurality of indoor units are connected to an outdoor unit; An outlet pipe temperature sensing step of detecting an outlet pipe temperature of an indoor unit which is an operation of the plurality of indoor units; And a cooperative control step of cooperatively controlling the indoor expansion valve of the indoor unit when the operation rate of the indoor unit, which is the operation detected in the operation rate detection step, is greater than or equal to a set value and the outlet piping temperature of all the indoor units that are the operation is higher than the reference temperature. do.

The reference temperature is a temperature lower than the weighted average temperature of the indoor unit in operation.

The cooperative control increases the opening degree of the indoor expansion valve of the indoor unit in which the outlet piping temperature is less than the weighted average temperature among the plurality of indoor units of the operation, and increases the opening degree of the indoor expansion valve of the indoor unit in which the outlet piping temperature of the plurality of indoor units of the operation is above the weighted average temperature. Lower.

The heating operation cooperative control method for a multi-type air conditioner according to the present invention includes: an operation rate detecting step of detecting an operation rate of an indoor unit which is an operation among the plurality of indoor units during heating operation of a multi-type air conditioner in which a plurality of indoor units are connected to an outdoor unit; And a cooperative control step of cooperatively controlling the indoor expansion valve of the indoor unit which is the driver when the operation rate of the indoor unit which is the operation detected in the operation rate detecting step is equal to or greater than a set value.

The cooperative control increases the opening degree of the indoor expansion valve of the indoor unit in which the outlet piping temperature of the plurality of indoor units is less than the weighted average temperature of the indoor unit in operation, and the indoor expansion of the indoor unit in which the outlet piping temperature of the plurality of indoor units of the operator is above the weighted average temperature. Lower the valve opening.

The heating operation cooperative control method of the multi-type air conditioner of the present invention configured as described above may substantially eliminate the heating medicine of a part of the indoor unit because the refrigerant is distributed by adjusting the indoor expansion valve when the refrigerant of the plurality of indoor units is insufficient. If the operation rate of the indoor unit of the operator is greater than or equal to the set value and the outlet piping temperature of all indoor units of the operator is higher than the reference temperature, the indoor expansion valve of the indoor unit of the operator is cooperatively controlled to cooperatively control the operation rate of the plurality of indoor units. When the two phase refrigerant can be generated according to the pressure drop of the indoor expansion valve that can be generated and the resulting noise, there is an advantage that can minimize unnecessary cooperative control.

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, and FIG. 2 is a control block diagram of a multi-type air conditioner according to the present invention.

 The multi-type air conditioner illustrated in FIG. 1 includes a plurality of indoor units 10, 20, 30, 40 installed in an interior of a building, an outdoor unit 50 installed outdoors, and a plurality of indoor units 10. 20, 30, 40 and the refrigerant pipes 52 and 54 connecting the outdoor unit 50 are configured.

In the indoor units 10, 20, 30, 40, refrigerant pipes 52, 54 are connected in parallel.

Each of the indoor units 10, 20, 30, 40 includes an indoor heat exchanger (11), 21, 31, 41, and a heat exchanger (11), (21) for exchanging refrigerant and indoor air. 31, 41 and indoor blowers 12, 22, 32, 42 for circulating indoor air to the indoor units 10, 20, 30 and 40, and to expand the refrigerant. It includes an indoor expansion valve (14, 24, 34, 44, LEV: Linear expansion valve).

The indoor expansion valves 14, 24, 34 and 44 are refrigerant pipes between the indoor heat exchangers 11, 21, 31 and 41 and the outdoor heat exchanger 70 described later of the outdoor unit 50. The indoor unit 10, 20, 30, 40 is installed in the refrigerant pipe located in the interior.

The indoor expansion valves 14, 24, 34 and 44 have an opening degree according to the target subcooling degree (for example, 5 ° C) of the indoor units 10, 20, 30 and 40 during heating operation. Is determined.

Typically, the supercooling during the heating operation is the difference between the liquid pipe temperature (ie, the indoor heat exchanger piping temperature) and the condenser outlet temperature (ie, the outlet piping temperature of the indoor heat exchanger), and the indoor expansion valve (14) when the subcooling increases. The pressure drop of the refrigerant passing through the (24) 34, 44 increases, and the pressure drop of the refrigerant passing through the indoor expansion valves 14, 24, 34, 44 decreases when the degree of subcooling decreases.

That is, when the opening degree of the indoor expansion valves 14, 24, 34, 44 is lowered, the pressure drop of the refrigerant passing through the indoor expansion valves 14, 24, 34, 44 becomes large, and the supercooling degree is Increase, and flow rate decreases. On the other hand, when the opening degree of the indoor expansion valves 14, 24, 34, 44 is increased, the pressure drop of the refrigerant passing through the indoor expansion valves 14, 24, 34, 44 becomes small, and the supercooling The degree is lowered and the flow rate is increased.

Meanwhile, the outdoor unit 60 includes an accumulator 61 through which only a gas refrigerant passes, a compressor 62 and 63 that receive and compress a gas refrigerant passing through the accumulator 61, and an outdoor heat exchanger with the refrigerant and outdoor air. A heat exchanger 70, an outdoor blower 71 installed near the outdoor heat exchanger 70 to blow outdoor air to the outdoor heat exchanger 70, and compressed by the compressors 62 and 63 during the cooling operation. The refrigerant flows to the outdoor heat exchanger (70), the refrigerant passing through the indoor heat exchanger (51) to the accumulator (61), and the refrigerant compressed by the compressors (62) and (63) during the heating operation. Cooling / heating switching valve 72 which is a four-way valve which flows to the heat exchanger 51 and flows the refrigerant which passed the outdoor heat exchanger 70 to the accumulator 61, and the outdoor expansion mechanism which expands a refrigerant. (73).

The outdoor expansion mechanism 73 is installed in the refrigerant pipe located inside the outdoor unit 60 among the refrigerant pipes between the indoor heat exchangers 11, 21, 31, 41 and the outdoor heat exchanger 70.

The outdoor expansion mechanism 73 includes an outdoor expansion valve (LEV: Linear expansion valve) for expanding the refrigerant, a bypass flow path 75 formed so that the refrigerant bypasses the outdoor expansion valve 74, and a bypass during heating operation. And a check valve 76 provided in the bypass flow path 75 so as to block the pass flow path 75.

The outdoor expansion valve 74 is opened to a predetermined size during the heating operation so that the refrigerant condensed in the indoor heat exchanger 11, 21, 31, 41 is sprayed into the liquid before being introduced into the outdoor heat exchanger 70. Inflate.

The air conditioner according to the present embodiment is an indoor heat exchanger temperature sensor 15 for measuring the temperature of the indoor heat exchangers 11, 21, 31, 41 of the indoor units 10, 20, 30, 40. 25) (35) (45) and the indoor piping of the indoor units (10) (20) (30) and (40), the outlet piping temperature of the indoor heat exchanger (11) (21) (31) (41) during the heating operation, Outlet piping temperature sensor 16, 26, 36, 46 to measure, and operation units 18, 28, 38, 48 for operating the indoor units 10, 20, 30, 40 and And a control unit 80 for controlling the compressors 62 and 63 and the heating / cooling switching valve 72 and the like according to the operation of the operation units 18, 28, 38, and 48.

The operation units 18, 28, 38, and 48 are provided in at least one of a control panel installed at each indoor unit to input a driving command, a remote controller connected to each indoor unit, and an integrated operation unit to which both indoor units are connected.

The control unit 80 controls the indoor heat exchanger temperature sensors 15 and 25 so that the indoor expansion valves 14, 24, 34, 44 maintain the target subcooling (eg, 5 ° C.) during heating operation. The indoor expansion valves 14, 24, 34, 44 are controlled according to the sensing values of the 35 and 45 and the outlet pipe temperature sensors 16, 26, 36 and 46. (10) If the indoor unit lacking the coolant supply among the (20), 30, 40 is present, that is, if the cooperative control condition is sufficient to supply the coolant to the insufficient indoor supply that is the coolant supply, the indoor unit 10 (operation) ( Cooperative control of the indoor expansion valves 14, 24 and 34 of 20 and 30 is carried out.

Here, the cooperative control condition is that the operation rate of the plurality of indoor units 10, 20, 30, 40 is equal to or higher than a set value (for example, 70%), The outlet piping temperatures T1, T2 and T3 are higher than the reference temperature.

And, the cooperative control increases the opening degree of the electronic expansion valve of the indoor unit lacking the refrigerant supply so that the refrigerant is sufficiently supplied to the indoor unit having insufficient refrigerant among the plurality of indoor units (10, 20, 30) of the operation, the refrigerant supply is insufficient The opening degree of the expansion valves 14, 24 and 34 of the indoor units 10, 20 and 30 in operation is adjusted to reduce the opening degree of the expansion valve of the indoor unit other than the indoor unit.

On the other hand, the operation rate of the plurality of indoor units 10, 20, 30, 40 simply ignores the capacity of each of the plurality of indoor units 10, 20, 30, 40, simply indoor units 10, 20, 30 It is also possible to determine according to the number of driving of the (40), in consideration of the capacity of each of the plurality of indoor units 10, 20, 30, 40, in the entire indoor unit (10, 20, 30) of the driver It may also be determined according to the actual heating power required (i.e. sum of the capacities of the indoor units 10, 20, 30 / operator sum of the capacities of the entire indoor units 10, 20, 30, 40). Do.

For example, the plurality of indoor units 10, 20, 30, 40 are the first to fourth indoor units, the capacity of the first indoor unit 10 is 48 kW, and the second to the fourth indoor units 20, 30. (40) If each of the plurality of indoor units 10, 20, 30, 40 is only 7kW, and only the first to third indoor units 10, 20, 30 operate, the plurality of indoor units 10, 20 ( The operation rate of 30) (40) is 75% when determined according to the number of operation of the indoor unit, while 89.8% (determined according to the actual heating power required by the driver indoor units 10, 20, 30 as a whole. = (48 + 7 + 7) / (48 + 7 + 7 + 7)).

When at least one of the plurality of indoor units 10, 20, 30, 40 differs in capacity, the actual heating power required by the entire indoor units 10, 20, 30, which are driving, for a more accurate operation rate detection. It is preferable to determine according to the following, and the operation rate of the plurality of indoor units 10, 20, 30, 40 is determined according to the actual heating power required by the entire indoor units 10, 20, 30, which are driving. It explains by doing.

On the other hand, the cooperative control condition as described above ignores the operation rate of the plurality of indoor units 10, 20, 30, 40, and the cooperative control is the operation rate of the plurality of indoor units 10, 20, 30, 40. If too low, the two-phase flow phenomenon due to excessive pressure drop and the refrigerant noise may be generated in the indoor expansion valve having a reduced opening degree. In order to prevent the two-phase flow phenomenon and the refrigerant noise according to the above, If the operation rate of the plurality of indoor units 10, 20, 30, 40 is more than the set value, the cooperative control should be performed.

 On the other hand, the reference temperature is a temperature lower than the weighted average temperature (Tavg) of the outlet piping temperature (T1), (T2), (T3) of the indoor units (10), (20), and (30), which is the operation, and ensures stability during cooperative control. Is the temperature considered for.

Here, the weighted average temperature Tavg is a temperature in consideration of the capacity of each indoor unit 10, 20, 30 that is the driving, and is calculated as in Equation 1.

[Equation 1]

Here, C1, C2, ... Cn is the capacity of each room (10, 20, 30) driving, and T1, T2, ... Tn is each indoor unit (10) (20) (30) of driving. Is the outlet piping temperature of and Ct is the sum of the capacities of the indoor units 10, 20, 30 that are operating.

For example, the set temperature is set to 7 ° C, the first to third indoor units 10, 20 and 30 are in operation, and the outlet piping temperature of the first indoor unit 10 having a 48 kW capacity is 39 ° C, When the outlet piping temperature of the second indoor unit 20 having a capacity of 7 kW is 42 ° C, and the outlet piping temperature of the third indoor unit 30 having a capacity of 7 kW is 31 ° C, the weighted average temperature is 38.43 ° C and the reference temperature is 31.43. ℃, and since all the indoor unit operating the outlet pipe temperature is lower than the reference temperature 33.43 ℃ indoor unit, in this case, the control unit 85 detects that the conditions for stable cooperative control is not established.

On the other hand, the set temperature is set to 7 ° C, the first to third indoor units 10, 20, 30 are in operation, and the outlet piping temperature of the first indoor unit 10 having a capacity of 48 kW is 39 ° C, and 7kW. When the outlet piping temperature of the second indoor unit 20 of the capacity is 42 ° C., and the outlet piping temperature of the third indoor unit 30 of the 7 kW capacity is 37 ° C., the weighted average temperature is 39.1 ° C. and the reference temperature is 32.1 ° C. And, since all the indoor unit operating the outlet pipe temperature is higher than the reference temperature 32.1 ℃, in this case, the control unit 85 detects that the conditions for stable cooperative control is established.

When the cooperative control condition as described above is carried out without comparing the outlet piping temperatures T1, T2, and T3 of all indoor units 10, 20 and 30 in operation with the reference temperature, the refrigerant is distributed by cooperative control. Is difficult (for example, when a part of the indoor unit is a cryogenic temperature that is difficult to rise to the proper heating temperature by the cooperative control) cooperative control may proceed unnecessarily, in order to minimize such unnecessary cooperative control If the outlet piping temperatures T1, T2, T3 of the indoor units 10, 20, 30 are higher than the reference temperature, cooperative control should be carried out.

Hereinafter, the cooperative control will be described in detail. The control unit 85 determines that the outlet piping temperature among the indoor units 10, 20 and 30, which is the driver, when the cooperative control condition as described above is established, is greater than or equal to the weighted average temperature Tabg. The opening degree of the indoor expansion valve of the indoor unit is also lowered, and the opening degree of the indoor expansion valve of the indoor unit of which the outlet piping temperature is less than the weighted average temperature (Tavg) is also increased.

Meanwhile, 90 shown in FIG. 1 indicates that the indoor units 10, 20, 30, 40 and the outdoor unit 60 transmit data between the indoor units 10, 20, 30, 40 and the outdoor unit 60. ) Is a connection wire to connect.

3 is a flowchart illustrating an embodiment of a heating operation cooperative control method of a multi-type air conditioner according to the present invention.

First, during the heating operation of the multi-type air conditioner, the control unit 85 drives the compressors 62 and 63, and switches the air-conditioning switching valve 72 to the heating mode. (S1)

Under such control, the refrigerant compressed in the compressors 62, 63 is condensed in the indoor heat exchangers 11, 21, 31, 41, expanded in the outdoor expansion valve 74, and the outdoor heat exchanger. After evaporation at 70 it is circulated to compressors 62 and 63.

The control unit 85 controls the indoor expansion valves 14, 24, 34, 44 according to the target superheat degree of each indoor unit 10, 20, 30, 40 during the above control. (S2)

In the heating operation as described above, the indoor heat exchanger temperature sensors 15, 25, 35, and 45 measure the temperature of the indoor heat exchangers 11, 21, 31, and 41 and output them to the control unit 85. The outlet pipe temperature sensors 16, 26, 36, and 46 measure the outlet pipe temperature of the indoor heat exchangers 11, 21, 31, and 41 and output them to the control unit 85. Reference numeral 85 denotes a difference between the temperature value output from the indoor heat exchanger temperature sensors 15, 25, 35 and 45 and the temperature value output from the outlet piping temperature sensors 16, 26, 36 and 46. Calculates the current subcooling degree of each indoor unit that is operated, and increases the opening value of the indoor expansion valves 14, 24, 34, 44 so that the current subcooling reaches the target subcooling degree of each indoor unit; Reduce

In addition, the control unit 85 determines whether the heating operation as described above is a cooperative control condition, and for the sake of clarity, a part of the plurality of indoor units 10, 20, 30, 40 is described below. Only 20) and 30 will be described as heating operation.

In order to determine whether the cooperative control conditions as described above are satisfied, the control unit 85 confirms the operation of the operation units 18, 28, 38, and 48, and accordingly, the indoor units 10, 20, 30 that are drivers. The weighted average temperature Tavg is calculated by weighted average of the outlet pipe temperatures T1, T2, and T3 of the indoor units 10, 20, and 30 which are the driving units.

Then, the control unit 85 is the operation rate of the indoor unit is more than the set value, the outlet piping temperature (T1) (T2) (T3) of all indoor units 10, 20, 30 that is the operation is the reference temperature (that is, the weighted average If the temperature is lower than the set temperature (Tavg) or more, it is determined that the cooperative control condition is satisfied, and the outlet piping temperature (T1) (T2) (T3) of all indoor units where the operation rate of the indoor unit is less than or equal to the set value is a reference. If the temperature is lower than the cooperative control condition is determined not to be satisfied (S3).

If it is determined that the control unit 85 satisfies the cooperative control condition, the target subcooling of the indoor expansion valve 34 of the indoor unit 30 in which the outlet piping temperatures T1, T2, and T3 is less than the weighted average temperature Tabg. By lowering the degree by the set value, the opening value of the indoor electromagnetic expansion valve 34 is increased, and the indoor expansion valves of the indoor units 10 and 20 whose outlet piping temperatures T1, T2, and T3 are equal to or greater than the weighted average temperature Tavg. 14) The target subcooling degree of (24) is increased by the set value, thereby lowering the opening value of the indoor solenoid expansion valves (14) and (24).

In the control as described above, less refrigerant is supplied to the indoor units 10 and 20 in which the outlet piping temperatures T1, T2, and T3 were above the weighted average temperature Tabg, than before the cooperative control. The indoor unit 30 in which the temperatures T1, T2, and T3 were less than the weighted average temperature Tavg is supplied with more refrigerant than before the cooperative control, and the indoor units 10, 20, and 30 which are operating. The flow rate distribution between each indoor unit 10, 20, 30 is achieved by controlling the respective indoor expansion valves 14, 24, 34 on the basis of the changed target subcooling degree.

On the other hand, the present invention is not limited to the above embodiment, and it is also possible to consider only the operation rate of a plurality of indoor units without considering the magnitude of the outlet piping temperature and the reference temperature of the indoor unit in which the cooperative control condition is the operation. Of course, various implementations can be made within the technical scope to which it belongs.

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 control block diagram of a multi-type air conditioner according to the present invention;

3 is a flowchart illustrating an embodiment of a heating operation cooperative control method of a multi-type air conditioner according to the present invention.

<Explanation of symbols on main parts of the drawings>

10,20,30,40: Indoor unit 11,21,31,41: Indoor heat exchanger

14, 24, 34, 44: Indoor expansion valve 16, 26, 36, 46: Outlet piping temperature sensor

18, 28, 38, 48: control panel 60: outdoor unit

70: outdoor heat exchanger 72: air conditioning switch

85: control unit

Claims (6)

An outdoor unit including a compressor, a cooling / heating switching valve, an outdoor expansion device, and an indoor heat exchanger, A plurality of indoor units connected to the outdoor unit and a refrigerant pipe, including an indoor heat exchanger and an indoor expansion valve, and including an outlet pipe temperature sensor for detecting an outlet pipe temperature of the indoor heat exchanger during a heating operation; And a control unit configured to cooperatively control the indoor expansion valve of the indoor unit when the operation rate of the plurality of indoor units is equal to or higher than a set value and the outlet pipe temperature of all indoor units that are operated is higher than the reference temperature during heating operation. When heating operation of multi-type air conditioner in which plural indoor units are connected to outdoor unit, A driving rate detecting step of detecting a driving rate of an indoor unit which is a driving among the plurality of indoor units; An outlet pipe temperature sensing step of detecting an outlet pipe temperature of an indoor unit which is an operation of the plurality of indoor units; And a cooperative control step of cooperatively controlling the indoor expansion valve of the indoor unit when the operation rate of the indoor unit, which is the operation detected in the operation rate detection step, is greater than or equal to a set value and the outlet piping temperature of all the indoor units that are the operation is higher than the reference temperature. Cooperative control method for heating operation of a multi-type air conditioner. The method of claim 2, The reference temperature is a heating operation cooperative control method of the multi-type air conditioner is a temperature lower than the set temperature of the weighted average temperature of the indoor unit operating. The method of claim 3, wherein The cooperative control increases the opening degree of the indoor expansion valve of the indoor unit in which the outlet piping temperature is less than the weighted average temperature among the plurality of indoor units that are operated, A cooperative control method for heating operation of a multi-type air conditioner which reduces the opening degree of an indoor expansion valve of an indoor unit in which an outlet piping temperature of a plurality of indoor units that is an operation is equal to or greater than the weighted average temperature. When heating operation of multi-type air conditioner in which plural indoor units are connected to outdoor unit, A driving rate detecting step of detecting a driving rate of an indoor unit which is a driving among the plurality of indoor units; And a cooperative control step of cooperatively controlling the indoor expansion valve of the indoor unit of the driver when the operating rate of the indoor unit, which is the operation detected in the operation rate detecting step, is greater than or equal to a set value. The method of claim 5, wherein The cooperative control increases the opening degree of the indoor expansion valve of the indoor unit in which the outlet piping temperature of the plurality of indoor units is less than the weighted average temperature of the indoor unit in operation, A cooperative control method for heating operation of a multi-type air conditioner which reduces the opening degree of an indoor expansion valve of an indoor unit in which an outlet piping temperature of a plurality of indoor units that is an operation is equal to or greater than the weighted average temperature.

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