JPH1183128A - Highly efficient multiple air conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly efficient multiple air conditioning system which equalizes, at a higher temperature, the temperatures of the heat exchangers within each indoor machine and gets thereby comfortable feeling of heating even for any air conditioning zone, by distributing a refrigerant properly even in case that the tolerable capacity of the heat exchanger of each indoor machine is various, or in case that the length of the pipe to each indoor machine is various. SOLUTION: In a highly efficient multiple air conditioning system which adjusts the flow of a refrigerant supplied to each indoor machine 2 and 3 from an outdoor machine 1 by the distribution valves 18 and 19 on the branch path where each of indoor machine 2 and 3 is arranged, the objective temperature of the heat exchanger for indoor service is set higher than the basis of the average temperature of all heat exchangers to indoor service, so that it may keep the aperture of the distribution valve corresponding to the indoor machine having maximum tolerable capacity over the specified aperture in heating operation, and the aperture of each distribution valve 18 and 19 is controlled based on this objective temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of connecting a plurality of indoor units to one outdoor unit in parallel, arranging indoor heat exchangers having different capacities in each of the indoor units, and controlling the temperature in each air conditioning zone. The present invention relates to a multi-capacity multi-air conditioner system adapted to control, and more particularly to control in a heating operation.

[0002]

2. Description of the Related Art Different capacity multi air conditioners, which control the temperature of a plurality of air conditioning zones with heat exchangers having the capacity suitable for each air conditioning zone, distribute the amount of refrigerant in accordance with the subcooling temperature of the indoor heat exchanger during heating operation. There are many things to control. As an example, an air conditioner disclosed in JP-A-8-61744 is known.

[0003] This is because a plurality of indoor units (50A, 50B,
50C) to the outdoor unit (3) via the branch unit (40).
0) is connected in parallel to each indoor unit (50
A, 50B, and 50C) include an indoor unit-side heat exchanger (18).
A, 18B, 18C) and blowers (24A, 24B, 24)
C) is provided, and the indoor unit side heat exchangers (18A, 18A) are provided.
B, 18C), the flow control valves (14A, 14B,
14C), the air that has been heat-exchanged by the heat exchanger is guided to a duct, and the air volume is individually adjusted through VAV units provided for each air conditioning zone so that the temperature-controlled air is supplied to each air conditioning zone. It was made. In addition, outdoor unit (30)
Has a variable capacity compressor (1), a heat exchanger (6),
A blower (21) is provided, and a heating operation expansion valve (7) is provided on a path leading from the heat exchanger (6) to the flow control valve.

During the heating operation, the refrigerant pressurized by the compressor 1 is supplied to the flow control valves (14A, 14B, 14B).
C) is distributed to the indoor unit side heat exchangers (18A, 18B, 18C) of each indoor unit at a ratio determined by the opening degree adjustment of C), and the heat exchanger radiates the refrigerant supplied from the compressor (1). To condense and liquefy, heating the air passing through the heat exchanger. Thereafter, the pressure is reduced at the expansion valve (7) for heating operation of the outdoor unit to become a gas-liquid mixed refrigerant, which absorbs heat from the air passing therethrough in the heat exchanger (6), evaporates and returns to the compressor (1). It has become. Then, the flow control valves (14A, 14B, 14
C), each indoor unit side heat exchanger (18A, 18B, 1)
The supercooling degree of 8C) is adjusted to be kept constant, and control is performed to stabilize the blown air temperature in each indoor unit.

[0005]

The above-mentioned air conditioner combines a heat pump multi-system with a VAV package system and controls the room temperature by adjusting the air volume. Each indoor unit is equipped with an indoor heat exchanger and an indoor heat exchanger. It has a conventional configuration in which the air blown from the fan passes through the heat exchanger and exchanges heat with the refrigerant in the cycle, and has a heat exchanger with a large allowable capacity in the air conditioning transition period at the beginning of the heating operation. Normally, the blower amount is set to be larger for the indoor unit so as to match it.

[0006] In such a transition period of air conditioning, even when the control for keeping the degree of supercooling constant is performed as in the above-mentioned prior art, the heat exchanger may be changed depending on the magnitude of the heating load or the amount of air blow. The temperature of itself varies. Especially, in the case of indoor heat exchangers that have a large capacity, it is necessary to supply heat that matches the capacity. Therefore, there is a disadvantage that a large amount of low-temperature air is blown out and the heating feeling is deteriorated. Further, since the pipe lengths from the outdoor unit to each indoor unit are different, a difference in the degree of supercooling occurs due to the difference in the pipe length, and the air conditioning control based on the degree of supercooling is not easy in the first place.

Therefore, in the present invention, even when the allowable capacity of the heat exchanger of each indoor unit is different or when the pipe length to each indoor unit is greatly different, the refrigerant is appropriately distributed to each of the indoor units. It is an object of the present invention to provide a different capacity multi air conditioner system in which a heat exchanger temperature of an indoor unit is made equal at a high temperature and a comfortable heating feeling can be obtained for heating in any air conditioning zone.

[0008]

In order to achieve the above object, a different capacity multi-air conditioner system according to the present invention has an outdoor unit and a plurality of indoor units provided in parallel with the outdoor unit. And the indoor unit has an indoor heat exchanger, the outdoor unit is a compressor, an outdoor heat exchanger,
The indoor unit has an expansion device, and at least two of the indoor units have different allowable capacities of the indoor heat exchanger, and each indoor unit is provided with a refrigerant flow rate supplied to the indoor unit from the outdoor unit. In the heating operation, the target temperature of the indoor heat exchanger is set so that the valve opening of the distribution valve corresponding to the indoor unit having the maximum allowable capacity is maintained at or above the predetermined opening during heating operation. The average temperature of the heat exchanger is set higher than the reference temperature, and the valve opening of each of the distribution valves is controlled based on the target temperature (claim 1).

For example, when refrigerant is distributed to two indoor units, two indoor units are provided in parallel with the outdoor unit, and the indoor heat exchanger provided in one indoor unit and the other indoor unit are provided. The indoor heat exchanger provided in the unit has a different allowable capacity, and the target temperature of the indoor heat exchanger is set higher than this based on the average temperature of the heat exchanger temperatures of the two indoor units. The valve opening of each distribution valve is controlled based on the target temperature (claim 3).

Therefore, the refrigerant pressurized by the compressor of the outdoor unit enters the indoor heat exchanger of the indoor unit,
Here, it is condensed and liquefied and the passing air is heated. Thereafter, the air is decompressed by the expansion device of the outdoor unit and enters the outdoor heat exchanger, where it absorbs heat from the passing air, evaporates and returns to the compressor.

It has been confirmed by experiments that the indoor heat exchanger of each indoor unit has a different temperature due to a difference in room temperature and air flow during the air conditioning transition period. Since the target temperature of the heat exchanger is set based on the average temperature of all indoor heat exchangers, the target temperature is set lower for indoor heat exchangers with relatively high temperatures. The degree of opening is smaller than the opening degree, the flow rate of the refrigerant is suppressed, and conversely, for the indoor heat exchanger whose temperature has decreased due to a large heating load or a large amount of ventilation, Increase the opening of the distribution valve, or
Maintaining the maximum opening increases the distribution amount of the refrigerant. This makes it possible to make the temperature of the indoor heat exchanger whose temperature has decreased equal to the temperature of the other indoor heat exchangers.

In addition, the target temperature of the heat exchanger is set higher than the average temperature of all the heat exchangers. In addition, it is possible to supply a large amount of high-temperature and high-pressure refrigerant by always increasing the opening degree of the distribution valve, and it is possible to appropriately distribute the refrigerant without reducing the heating capacity as much as possible. In other words, the refrigerant is distributed so that the heat exchanger temperature of each indoor unit is equal at a high temperature.

When only a part of the indoor units is operated, the distribution valve on the branch where the part of the indoor units is disposed is fully opened, and the distribution valve on the branch where the other indoor units are disposed. Is fixed at a predetermined opening degree in the closing direction, and the heat exchange capacity of the indoor heat exchanger provided in the operating indoor unit may be controlled by varying the discharge capacity of the compressor. For example, to operate only one indoor unit in an air conditioner system including two indoor units, the distribution valve on the branch where the one indoor unit is arranged is fully opened, and the branch valve on the other indoor unit is arranged. Is fixed at a predetermined opening degree in the closing direction, and the heat exchange capacity of the indoor heat exchanger provided in one indoor unit may be controlled by varying the discharge capacity of the compressor of the outdoor unit. Item 4).

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 and FIG.
A multi-capacity multi-air conditioner system for air-conditioning two rooms (Room A and Room B) is shown. An outdoor unit 1 and indoor units 2 and 3 installed in each room are connected in parallel via a branching unit 4. I have.

The outdoor unit 1 is provided with a compressor 5, an outdoor heat exchanger 6, an expansion valve 7, and the like. A four-way valve 8 is connected to the discharge side of the compressor 5, and an outdoor fan 28 is connected through the four-way valve 8. One end of the outdoor heat exchanger 6 for exchanging heat with the air blown by the air is connected. The suction side of the compressor 5 is connected to an accumulator 9, and the inflow side of the accumulator 9 is connected to a four-way valve 8.
During the heating operation, the four-way valve 8 sends the refrigerant discharged from the compressor 5 to the branch unit 4 through the pipe 14 protruding from the outdoor unit 1 via the flow control valve 10 and flows out of the outdoor heat exchanger 6. Accumulator 9 for refrigerant
Through the compressor, the refrigerant is guided to the inflow side of the compressor 5, and during the cooling operation, the refrigerant protruding from the compressor 5 is sent to the outdoor heat exchanger 6, and the flow control valve 1
The refrigerant is sent from the branch unit 4 to the outdoor unit 1 via the accumulator 9 so as to be guided to the inflow side of the compressor 5 via the accumulator 9.

At the other end of the outdoor heat exchanger 6 housed in the outdoor unit 1, a check valve 11 and a capillary tube 12 bypassing the check valve are arranged in parallel. Flows through the check valve 11, and during the heating operation, the capillary 12
Through which the refrigerant flows. The expansion valve 7 and the flow control valve 13 are further connected via the check valve 11 and the capillary tube 12.
Are connected in series, and a pipe 1 projecting from the outdoor unit 1
It leads to 5.

The branch unit 4 has branch pipes 16 and 17 branching into two branches on the indoor unit side in accordance with the number of the indoor units, and the connecting paths 16 c and 17 c of the branch pipes 16 and 17 are connected to the pipe 1.
The branch passages 16a, 16b, 17a, 17b of the branch pipes 16, 17 are connected to pipes 22 to 25 extending from the branch unit 4. Distribution valves 18 and 19 are provided in the branch paths 17a and 17b of the branch pipe 17 to adjust the distribution ratio of the refrigerant flowing through each indoor unit. The distribution valves 18 and 19 are connected to the branch paths 17a and 1
A well-known device that continuously and variably controls the cross section of the flow path 7b by a motor actuator based on an external signal is used.

Each of the indoor units 2 and 3 includes an indoor heat exchanger 20,
The indoor heat exchanger 20 of the indoor unit 2 disposed in the room A is connected to the pipes 22 and 23 extending from the branch unit 4, and is provided in the room B. Are connected to pipes 24 and 25 extending from the branch unit 4, and the indoor heat exchangers 20 and 21 are respectively connected by indoor fans 26 and 27. It is designed to be a heat exchanger with the air to be blown. Indoor heat exchanger 2 for each indoor unit 2 and 3
0 and 21 differ in allowable heat exchange capacity, and the present invention is characterized in that a multi air conditioner having a heat exchanger having an allowable capacity different for each indoor unit is to be controlled. .

As shown in FIG. 3, each of the indoor units 2 and 3 has a room temperature sensor 30a for detecting the intake air temperature.
30b and heat exchanger temperature sensors 31a and 31b arranged near the fins or the leeward side of the indoor heat exchanger and detecting the temperature of the indoor heat exchanger are provided, and signals from these sensors are Indoor operation unit 3 provided for each room
The indoor control units 33a, 33a,
33b.

The indoor control units 33a and 33b receive signals from the sensors and the indoor operation unit, and input signals from the indoor fan 34.
a and 34b are speed-controlled, and based on a predetermined program given in cooperation with the outdoor control unit 35 of the outdoor unit 1,
Control of the capacity of the compressor 5 and switching of the four-way valve 8;
The opening control of the flow control valves 10 and 13 and the opening control of the distribution valves 18 and 19 of the branch unit 4 are performed.

In the following, a control example of the air conditioner cycle by the control unit will be described. During the cooling operation, the four-way valve 8 is switched as shown by the broken line in FIG. The air enters the outdoor heat exchanger 6 through the air outlet 8, and the outdoor heat exchanger 6 is used as a radiator to radiate heat to the air sent from the outdoor fan 28 and cool it. Thereafter, the pressure is reduced by the expansion valve 7 through the check valve 11 and sent to the branch unit 4. The refrigerant sent to the branch unit 4 is distributed to each branch according to the degree of opening of the distribution valves 18 and 19, flows, and is sent to the indoor units 2 and 3 through the pipes 23 and 25. The indoor heat exchangers 20 and 21 of each indoor unit are used as heat absorbers, and the indoor fans 26 and
The air sent from 27 is cooled. Then, pipe 22,
The refrigerant which is sent to the branching unit 4 via the internal unit 24 and flows out from each indoor unit is sent to the outdoor unit 1 collectively, enters the accumulator 9 via the four-way valve 8, where the refrigerant is separated into gas and liquid, and then to the compressor 5. Will be returned.

On the other hand, during the heating operation, the four-way valve 8 is switched as shown by the solid line in FIG. 2, and the refrigerant pressurized by the compressor 5 passes through the four-way valve 8 and the flow control valve 10. It enters the branch unit 4, flows through the pipes 22, 24 leading to the indoor units 2, 3, and is sent to each indoor unit. The refrigerant sent to each indoor unit is supplied to each indoor heat exchanger 20, 21.
Is used as a radiator, and radiates heat to the air sent from the indoor fans 26 and 27 here. Thereafter, in the branch unit 4, the refrigerant of each indoor unit is collected via the distribution valves 18 and 19, and the refrigerant is reduced in pressure by the expansion valve 7 of the outdoor unit 1, and the check valve 11
And enters the outdoor heat exchanger 6. Then, using the outdoor heat exchanger 6 as a heat absorber, the refrigerant flowing into the outdoor heat exchanger 6 exchanges heat with the air sent from the outdoor fan 28, and then the refrigerant flows to the accumulator 9 via the four-way valve 8. It is returned to the compressor 5 after entering and gas-liquid separation. Even during the heating operation, the flow rate of each refrigerant distributed to each branch is determined according to the degree of opening of the distribution valves 18 and 19.

Among the above-mentioned controls, the refrigerant distribution control by the distribution valves 18 and 19 during the heating operation will be described below. The control unit is shown in the flowchart of FIG. 4 as a part of the main routine of the heating operation control. In step 50, the room temperature sensors 30a, 30
b and signals from the heat exchanger temperature sensors 31a and 31b and the signals from the indoor operation units 32a and 32b. In the next step 52, it is determined whether there is a request for two-room control for heating control of both the room A and the room B or a request for one-room control for heating control of one of the rooms. If there is a request for two-chamber control automatically or manually based on signals from the various sensors described above, the process proceeds to step 54, where the heat of the A-chamber detected by the heat exchanger temperature sensors 31a and 31b is detected. As shown in the same step based on the exchanger temperature (α) and the heat exchanger temperature (β) in the room B, the target temperature of each of the indoor heat exchangers 20 and 21 is calculated as the average temperature of the two indoor heat exchangers. Is calculated as a temperature obtained by adding 2 ° C. to the temperature, and in step 56, the opening degrees of the distribution valves 18 and 19 are controlled based on the calculated target heat exchanger temperature.

Here, the average temperature + 2 ° C. is used as the target heat exchanger temperature because the difference between the average temperature + 2 ° C. and the average temperature + 2 ° C. for the indoor unit having a low heat exchanger temperature. ) Is increased to increase the opening of the corresponding distribution valve, and for indoor units having a high heat exchanger temperature, the difference from the target heat exchanger temperature is made smaller or negative to make the opening of the distribution valve smaller. However, this is because a large amount of refrigerant flows to the one with a larger heating load. Further, the reason why “+ 2 ° C.” is added is to keep the valve opening on the side with a large heating load in a large state so that the valve opening is not stabilized in a small state.

In the above configuration, the indoor heat exchanger in room A (indoor heat exchanger A) is a 25-type heat exchanger having a heating allowable capacity of 2.5 KW, and the indoor heat exchanger in room B is used. (The indoor heat exchanger B) has a heating allowable capacity of 3.2 KW3.
Looking at the experimental results in the case of using a type 2 heat exchanger to heat a room corresponding to each allowable capacity, immediately after starting the heating by switching the four-way valve 8, as shown by the solid line in FIG. Then, the temperature of the indoor heat exchangers A and B of each indoor unit gradually increases from approximately 20 ° C. In the heating transition period, since the indoor units in both rooms are operated at the maximum capacity, the indoor unit 3 in the room B has a larger airflow of the indoor fan than the indoor unit 2 in the room A. The indoor heat exchanger B is
The temperature once drops due to this blowing.

When the temperature of the indoor heat exchanger B decreases, the target temperature (= average temperature + 2 ° C.) decreases to a value between the indoor heat exchanger A and the indoor heat exchanger B, and the indoor heat exchanger B decreases. Exchanger A
Tries to reduce the temperature to the target temperature,
Is adjusted in a direction to decrease. On the other hand, the indoor heat exchanger B attempts to increase the valve opening of the distribution valve 19 in order to increase the temperature to the target temperature. Therefore, as shown in the change over time of the distribution valve in FIG. 5, although the opening degree of the distribution valve 18 corresponding to the indoor unit 2 in the room A is small (see the characteristics of the distribution valve A), the indoor unit in the room B is 3
Is fully opened in the early stage of heating so that sufficient heating capacity can be obtained, so that the opening degree does not increase any more, and the fully opened state is maintained (distribution valve B). Characteristics).

As a result, a large amount of the refrigerant supplied from the compressor flows through the branch 16b on the side where the indoor heat exchanger B is disposed, and once the temperature of the indoor heat exchanger B decreases.
Again quickly rises to become equal to the temperature of the indoor heat exchanger A. Thereafter, the opening degree of the distribution valve 19 corresponding to the indoor unit 3 in the room B is maintained in the fully opened state, and the temperature of the indoor heat exchangers in the two rooms is corresponding to the indoor unit 2 in the room A so as to be equal. The opening of the distribution valve 18 is automatically adjusted.
This state is continued. Accordingly, the blowing temperature of the indoor unit 3 in the indoor unit 3 in the room B is temporarily corrected to be low in the initial stage of heating with a large amount of air, but this is corrected and the temperature of the indoor heat exchanger is high. , And the good heating feeling is maintained in the room B as in the case of the room A, and a transition is made to the stable state.

In the above two room temperature control, if there is a request to control heating of only one of the rooms, the process proceeds from step 52 to steps 58 and 60, and the control is performed as follows. For example, when heating control is performed only for the room B,
The opening of the distribution valve 19 corresponding to the room B is set to the full opening, and the opening of the distribution valve 18 corresponding to the room A is set to the minimum opening (for example, the opening of about 2/5 of the fully opened state) allowing the flow of the refrigerant. The heating capacity is adjusted by fixing and controlling the discharge capacity of the compressor 5. As described above, the distribution valve 1 on the side where the heating control is not performed
The reason why the opening of 8 is not fully closed and the minimum opening that allows the flow of the refrigerant is that if the distribution valve 18 is fully closed, the refrigerant unnecessarily accumulates on the branch where the temperature control is not performed. Becomes
This is because the shortage of the amount of refrigerant required in the cycle is caused, so that only the flow of the refrigerant is ensured so that the operation of the cycle is not hindered. Therefore, even in the present air conditioner system on the premise of multi-room heating control, appropriate one-room heating control can be performed similarly to the air-conditioning system that performs heating control of only one room.

In the above configuration example, control for heating two rooms has been described as the best mode.
Even when three or more rooms are heated, the distribution valves corresponding to the other indoor units are opened so that the opening degree of the distribution valve corresponding to the heat exchanger requiring the most heating capacity is maintained in the fully opened state. In order to realize this, the target temperature of each indoor heat exchanger is set to the average temperature of all indoor heat exchangers + 2 ° C, and the valve of each distribution valve is set based on the target temperature. The opening may be controlled. In addition, "+
By adding the term “2 ° C.”, the opening of the distribution valve corresponding to the indoor unit having the maximum capacity is kept large, but it goes without saying that this constant may be changed as appropriate depending on the cycle configuration and the like. Absent.

[0030]

As described above, according to the present invention,
A plurality of indoor units having indoor heat exchangers with different allowable capacities are connected in parallel to the outdoor units, and the distribution of refrigerant to each indoor unit is adjusted by controlling the distribution valve provided at the branch of each indoor unit. In the air conditioner system which performs the above operation, the target temperature of each indoor heat exchanger is set to be higher than the average temperature of all the indoor heat exchangers during the heating operation.

The temperature of all operating heat exchangers can be kept constant while suppressing a decrease in the temperature of the heat exchanger having a large allowable capacity requiring a heating capacity, and the capacity of the outdoor unit can be maximized. It is possible to perform the heating operation that is exhibited to the maximum extent. Further, since the temperatures of all the operating heat exchangers are controlled to be constant, the heat exchanger temperature does not decrease and the heating feeling is not impaired even for an indoor unit having a large air flow rate. Even in the case where the heating loads of the multi-capacity air conditioners with different capacities are significantly different, the refrigerant distribution can be appropriately controlled only by controlling the distribution valve. If the pipe length from the outdoor unit to each indoor unit is significantly different, it is difficult to control the refrigerant distribution according to the degree of subcooling of the indoor heat exchanger. Since the distribution of the refrigerant is determined from the viewpoint of equalizing the temperatures of the indoor heat exchangers, the refrigerant can be appropriately distributed. Since the above-mentioned effects can be obtained for the heat exchangers having different capacities, the heat exchangers can be directly used for the multi-air conditioner system having the same capacity. Further, when only a part of the indoor units is operated, instead of the flow distribution by the distribution valve, the distribution valve is fully opened for the operated indoor unit, and the heat exchange capacity is controlled by changing the capacity of the compressor. In this case, an appropriate heating capacity can be obtained.

[Brief description of the drawings]

FIG. 1 is an external view showing a layout of a different capacity multi air conditioner cycle according to the present invention.

FIG. 2 is a system configuration diagram of the different capacity multi air conditioner cycle shown in FIG.

FIG. 3 is a block diagram showing a control device for a multi-capacity multi-air conditioner cycle according to the present invention.

FIG. 4 is a flowchart illustrating a control processing example during a heating operation by the control device illustrated in FIG. 3;

FIG. 5 is an indoor heat exchanger temperature and an outlet temperature of an indoor unit in a room A, an indoor heat exchanger temperature and an outlet temperature of an indoor unit in a room B, and opening degrees of distribution valves A and B; It is a characteristic line which shows a time change with a state.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 outdoor unit 2, 3 indoor unit 4 branch unit 5 compressor 6 outdoor heat exchanger 7 expansion valve 8 four-way valve 18, 19 distribution valve 20, 21 indoor heat exchanger

Claims (4)

[Claims] 1. An outdoor unit comprising: an outdoor unit; and a plurality of indoor units provided in parallel with the outdoor unit, wherein the indoor unit has an indoor heat exchanger. It has a compressor, an outdoor heat exchanger, and an expansion device, and at least two indoor units have different allowable capacities of the indoor heat exchanger and are supplied from the outdoor unit to the indoor unit. The refrigerant flow rate can be adjusted by a distribution valve on the branch where each indoor unit is arranged, and during heating operation, the valve opening of the distribution valve corresponding to the indoor heat exchanger having the maximum allowable capacity is kept at a predetermined opening or more. The target temperature of the indoor heat exchanger is set higher than the average temperature of all the indoor heat exchangers, and the opening degree of each distribution valve is controlled based on the target temperature. A multi-air conditioner system with different capabilities. 2. When only some indoor units are operated,
The distribution valve on the branch where the part of the indoor units is disposed is fully opened, and the distribution valve on the branch where the other indoor units are disposed is fixed at an opening degree in a predetermined closing direction. 2. The multi-capacity air conditioner system according to claim 1, wherein the heat exchange capacity of the indoor heat exchanger provided is controlled by changing a discharge capacity of the compressor. 3. An indoor unit having an outdoor unit and two indoor units provided in parallel to the outdoor unit, and an indoor heat exchanger provided in one indoor unit is provided in the other indoor unit. 2. The different capacity multi air conditioner system according to claim 1, wherein the allowable capacity is different from that of the indoor heat exchanger. 4. When only one indoor unit is operated,
The distribution valve on the branch where the one indoor unit is arranged is fully opened, and the distribution valve on the branch where the other indoor unit is arranged is fixed at a predetermined opening degree in the closing direction, and provided on the one indoor unit. The different capacity multi air conditioner system according to claim 3, wherein the heat exchange capacity of the indoor heat exchanger is controlled by varying a discharge capacity of the compressor.