JP2001033119A - Multi-room type air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multi-room type air conditioner in which each indoor unit can be supplied with an appropriate quantity of refrigerant depending on the capacity thereof and the quantity of refrigerant in a circulation refrigerant circuit can be regulated appropriately depending on the operating state of each indoor unit. SOLUTION: The multi-room type air conditioner comprises an indoor unit 2 comprising indoor side heat exchangers 9, 10, 11 having different heat exchanging capacity coupled with electronic expansion valves 12a, 12b, 12c, a refrigerant distribution unit 3, and an outdoor unit 1 comprising a compressor 4 and an accumulator 5 provided, on the suction and delivery sides thereof, with pressure sensors 33b, 33a and a thermister 34, outdoor side heat exchangers 6, 7, 8 provided, in front and rear thereof, with an electronic expansion valve and a solenoid valve and set, respectively, with heat exchanging capacity corresponding to those of the indoor side heat exchangers 9, 10, 11. The quantity of refrigerant in the refrigerant circuit is regulated lower than the measurements of the pressure sensors 33b, 33a and the thermister 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room air conditioner for cooling or heating a plurality of indoor units to which one outdoor unit is connected. The present invention relates to a configuration of an outdoor heat exchanger.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a conventional multi-room air conditioner. 37 is an outdoor unit, 2 is a plurality of indoor units, and 3 is a refrigerant distribution unit. Outdoor unit 3
7 is a compressor 5 and an accumulator 4 connected thereto.
The indoor unit 2 includes indoor heat exchangers 9, 10, and 11, and electronic expansion valves 12a, 12b, and 12c connected thereto. The discharge port of the compressor 5 is connected to a first pipe 13, and the suction port of the compressor 5 is connected to a second pipe 14. The first pipe 13 is connected via an electromagnetic on-off valve 21a to an inlet of the outdoor heat exchanger 40, which is on the inflow side during cooling, and the discharge port of the outdoor heat exchanger 40 is provided with an electronic expansion valve 26 having an electronic expansion valve 26. Five pipes 18
Is a seventh pipe 19 branched in parallel, and the electronic expansion valve 12
a, a plurality of indoor heat exchangers 9 via 12b and 12c,
10 and 11 are connected. Same-side heat exchanger 9, 10
The eighth pipe 20 is connected in parallel from the outlets of the first and second pipes 11 to the refrigerant distribution unit 3. In the refrigerant distribution unit 3, each of the eighth pipes 20 branches, and one of the branch pipes 29
Is connected to the fourth pipe 16 via electromagnetic on-off valves 31a, 31b and 31c, and the other branch pipe 30 is connected to the electromagnetic on-off valve 32a,
It is connected to the second pipe 14 via 32b and 32c. In the same configuration, when the heat capacities of the indoor heat exchangers 9, 10 and 11 of the indoor unit 2 are different, the amount of refrigerant flowing into the indoor heat exchangers 9, 10 and 11 corresponding to the heat capacities is controlled. It is quite difficult, and each room may be under-cooled or over-cooled.
Also, if the outdoor heat exchanger is divided and provided, when the operation of a certain indoor unit is stopped, a refrigerant pool is generated in the outdoor heat exchanger where the operation is stopped and the refrigerant amount becomes insufficient or excessive in the refrigerant circuit. In some cases, the cooling capacity may be insufficient, or the pressure of the refrigerant may increase or the liquid may return.

[0003]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a multi-room air conditioner having a plurality of indoor heat exchangers having different heat capacities, the amount of refrigerant adapted to the heat capacity of each indoor heat exchanger. Multi-room air that can provide an outdoor unit that can supply air and that can appropriately adjust the amount of refrigerant in the refrigerant circuit in accordance with the operating conditions of the indoor unit and prevent insufficient cooling of each indoor unit or an increase in refrigerant pressure It is intended to provide a harmony device.

[0004]

According to the present invention, in order to solve the above-mentioned problems, a discharge side of a compressor is connected to a first pipe, a suction side is connected to a second pipe, and the first pipe is connected to a third pipe and a third pipe. Branched into four pipes, the third pipe was branched in parallel, and the first outdoor heat exchanger, the second outdoor heat exchanger, and the third outdoor heat exchanger during cooling operation via the first solenoid on-off valve. Connected to the inflow port on the inflow side of the vessel, respectively, the first outdoor heat exchanger,
From the outlets of the second outdoor heat exchanger and the third outdoor heat exchanger, connected to the fifth pipe via an electromagnetic on-off valve and an electronic expansion valve,
Inlet of the first outdoor heat exchanger, the second outdoor heat exchanger, and the third outdoor heat exchanger via a second electromagnetic on-off valve and branching in parallel a sixth pipe branched from the second pipe An outdoor unit connected to the first indoor heat exchanger that connects a seventh pipe branching in parallel from the fifth pipe to an inflow side during cooling operation through an electronic expansion valve, and a second chamber. Equipped with an inner heat exchanger and a third indoor heat exchanger, the first indoor heat exchanger, the second indoor heat exchanger and the outlet of the third indoor heat exchanger, the eighth pipe in parallel A plurality of connected indoor units and the same parallel eighth pipe are each further branched, one of the branches is connected to the second pipe via a third solenoid on-off valve, and the other is a fourth solenoid on-off valve. A refrigerant circuit comprising a refrigerant distribution unit connected to the fourth pipe via Simultaneous cooling and heating operation of the plurality of indoor units is enabled by opening and closing the first solenoid on-off valve, the second solenoid on-off valve, the third solenoid on-off valve, the fourth solenoid on-off valve, and the electronic expansion valve according to an operation mode. In the multi-room air conditioner, the heat exchange capacity of the first outdoor heat exchanger is set in accordance with the heat exchange capacity of the first indoor heat exchanger, and the second indoor heat exchanger is set. In accordance with the heat exchange capacity of, the heat exchange capacity of the second outdoor heat exchanger is set,
The heat exchange capacity of the third outdoor heat exchanger is set in accordance with the heat exchange capacity of the third indoor heat exchanger, and the first indoor heat exchanger and the second indoor heat exchanger are set. And, depending on the state of the third outdoor heat exchanger, to control the opening and closing of the first solenoid on-off valve and the second solenoid on-off valve, the first indoor heat exchanger,
An appropriate amount of refrigerant is circulated through the second indoor heat exchanger and the third indoor heat exchanger.

[0005] The controller determines an appropriate amount of refrigerant in the refrigerant circuit with respect to an operation state of the first indoor heat exchanger, the second indoor heat exchanger, and the third indoor heat exchanger. A refrigerant amount reference value, a refrigerant amount estimating unit that estimates a refrigerant amount in the refrigerant circuit, based on a measured value and an outside air temperature measured by a pressure sensor and a thermistor for measuring a refrigerant pressure and a refrigerant temperature of the refrigerant circuit. Comparing the refrigerant amount reference value with the estimated value of the refrigerant amount estimating unit, and determining whether the refrigerant amount in the refrigerant amount circuit is too small. A drive unit that performs opening and closing control of the electromagnetic on-off valve, the second electromagnetic on-off valve, other electromagnetic on-off valves, and the electronic expansion valve according to a predetermined control table.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted unless necessary. FIG. 1 is a refrigerant circuit diagram of a multi-chamber air conditioner showing the present embodiment, FIG. 2 is a control block diagram thereof, and FIG. 3 is a control diagram showing an example of control of an electromagnetic on-off valve and an electronic expansion valve.
FIG. 4 is a refrigerant amount adjustment control diagram by a drive unit described later, and FIG. 5 is an embodiment of a refrigerant amount determination reference diagram.

Next, the configuration of the refrigerant circuit of this embodiment will be described with reference to FIG. 1 surrounded by a dotted line is an outdoor unit, 2 is a plurality of indoor units similarly surrounded by a dotted line, and 3 is a refrigerant distribution unit. Compressor 4 in outdoor unit 1
And an accumulator 5 and a first outdoor heat exchanger 6, a second outdoor heat exchanger 7, and a third outdoor heat exchanger 8 connected thereto. In this embodiment, the same outdoor heat exchanger is provided. The first outdoor heat exchanger 6 has a heat capacity of about 50%, and the second and third outdoor heat exchangers 7 and 8 have a heat capacity of about 2%.
5% heat capacity is assigned. In the indoor unit 2, a first indoor heat exchanger 9 and a second indoor heat exchanger 1 to which electronic expansion valves 12a, 12b, and 12c are connected, respectively.
0 and the third indoor heat exchanger 11 are disposed in each room, and the indoor heat exchangers 9, 10 and 11 are also provided in the first indoor heat exchanger 9 like the outdoor heat exchanger. A heat capacity of about 50% is allocated, and a heat capacity of 25% is allocated to each of the second indoor heat exchanger 10 and the third indoor heat exchanger.

Next, the piping system will be described. The discharge port of the compressor 4 is connected to a first pipe 13 provided with a pressure sensor 33a and a thermistor 34, and the suction port of the compressor 4 is connected to a second pipe 14. The first pipe 13 branches into a third pipe 15 and a fourth pipe 16, and the third pipe 1
5 further branches into a branch pipe 15a and a branch pipe 15b, and the branch pipe 15a is connected to a pipe 23a through a first electromagnetic on-off valve 21a.
The pipe 23a is connected to the first outdoor heat exchanger 6.
However, it is connected to the outlet on the inflow side during the cooling operation. The branch pipe 15b further branches into a branch pipe 15c and a branch pipe 15d, and the branch pipe 15c is connected to a pipe 23b via a first electromagnetic on-off valve 22b, and the pipe 23b is connected to the second outdoor heat exchanger. 7 and the branch pipe 1
5d is connected to a pipe 23c via a first electromagnetic on-off valve 21c, and the pipe 23c is connected to an inflow port of the third outdoor heat exchanger 8.

A sixth pipe 17 branched from the second pipe 17
Further branches into branch pipes 17a, 17b and 17c, which are connected to the pipe 23a via a second electromagnetic on-off valve 22a, and which branch pipe 17b is connected via a second electromagnetic on-off valve 22c. To the pipe 23c,
c is connected to the pipe 23b via a second electromagnetic on-off valve 22b. The pipe 24 from the outlet of the first outdoor heat exchanger 6 passes through an electronic expansion valve 26, and the pipe 25 b passes from the second outdoor heat exchanger 7 via an electromagnetic valve 27.
However, a pipe 25a is connected to the third outdoor heat exchanger 8, and the pipes 25a and 25b become a merging pipe 25 provided with an electronic expansion valve 28, and the merging pipe 25 is connected to the pipe 24.
And is connected to the fifth pipe 18.

The fifth pipe 18 is a connection pipe for connecting the outdoor unit 1 and the indoor unit 2 and is branched in parallel before being connected to the indoor unit 2 to form a plurality of seventh pipes 19. The pipes 19 are each provided with the electronic expansion valve 12.
a, 12b, and 12c are connected to the outlets on the inlet side during the cooling operation of the indoor heat exchanger 9, the indoor heat exchanger 10, and the indoor heat exchanger 11.
Eighth pipes 20 are connected to the outlets of the indoor heat exchanger 9, the indoor heat exchanger 10, and the indoor heat exchanger 11, respectively. The eighth pipe 20 is connected to the refrigerant distribution unit 3. In the refrigerant distribution unit 3, the eighth pipe 20 further includes a branch pipe 29 via third electromagnetic on-off valves 31a, 31b and 31c and a branch pipe 30 via fourth electromagnetic on-off valves 32a, 32b and 32c. And the branch pipe 29
Are respectively connected to the fourth pipe 16, and the branch pipes 30 are respectively connected to the pipes 2 to form a refrigerant circuit of the multi-room air conditioner.

Next, the operation of the present embodiment during the cooling operation will be described. When all of the indoor units 2 are in the operating state, the first outdoor heat exchanger 6, the second outdoor heat exchanger 7, and the third outdoor heat exchanger 8 in the outdoor unit 1 are all In the operating state, the open / closed states of the electromagnetic on-off valve and the electronic expansion valve are as shown at the time of 100% operation in FIG. During the same operation, the electromagnetic on-off valves 21a, 21b, and 21c in the outdoor unit 1 are in the open state, and the electromagnetic on-off valves 22a, 22b, and 22c are in the closed state. The electronic expansion valves 26 and 28 and the electromagnetic on-off valve 27 disposed on the discharge port side of the outdoor heat exchangers 6, 7 and 8 are open, and the electronic expansion valves 12a and 12a in the indoor unit 2 are opened. 12b and 12c are also open. The electromagnetic on-off valve 32 in the refrigerant distribution unit 3
a, 32b, and 32c are open, and the electromagnetic on-off valve 3
1a, 31b and 31c are in the closed state.

In this state, the high-temperature and high-pressure refrigerant vapor discharged from the compressor 4 flows into the outdoor heat exchangers 6, 7 and 8 through the first pipe 13, and flows into the outdoor heat exchangers 6, 7 and 8. And 8, which are condensed by radiating heat to the outside of the room, become high-temperature and high-pressure refrigerant liquid, and expand through the fifth pipe 18 by the electronic expansion valves 12a, 12b, and 12c to become low-temperature and low-pressure refrigerant liquid, and become , 10 and 11 absorb the indoor heat and evaporate to change into low-temperature and low-pressure refrigerant vapor, flow into the second pipe 14 through the branch pipe 20 and are compressed again by the compressor 4 to be re-compressed by the high-temperature and high-pressure refrigerant vapor. One cycle during the cooling operation is completed. In a state in which the plurality of indoor heat exchangers 9, 10 and 11 having different heat capacities are all operating as described above, each outdoor heat exchanger 6, of the outdoor unit 1 corresponding to the heat capacity of each indoor heat exchanger, Since each of 7 and 8 corresponds to each other, it is possible to secure an appropriate amount of refrigerant for the capacity of each indoor side heat exchanger 9, 10 and 11, resulting in insufficient cooling of each room or excessive cooling or insufficient heating. Fear can be made very small.

Next, a case where the operation of one of the indoor heat exchangers 10 and 11 is stopped from the above-mentioned full operation state will be described. In the same operation state, the capacity of the indoor heat exchanger is 50% + 25% = about 75% operation state, and the open / close state of the solenoid on-off valve is as shown at 75% operation in FIG. The electromagnetic on-off valves in the outdoor unit 1 are such that the electromagnetic on-off valves 21a, 21c are in an open state, and the electromagnetic on-off valves 22a, 21b, 22b, 22c are in a closed state. The electromagnetic on-off valve 27 located at the discharge port of the outdoor heat exchanger 7 is closed, and the electronic expansion valves 26 and 28 are open. The electronic expansion valve 12a of the indoor unit 2 is open, and one of the electronic expansion valves 12b and 12c is open. The electromagnetic on-off valves 31a, 31
b and 31c are in a closed state, the electromagnetic on / off valve 32c is in an open state, and one of the electromagnetic on / off valves 32b and 32a is in an open state.

In this state, the outdoor heat exchanger 7
Becomes unused, and a refrigerant pool is generated in the outdoor heat exchanger 7. The amount of the refrigerant reservoir varies depending on the load in the full operation state or the timing of closing the electromagnetic on-off valve or the electronic expansion valve. When the amount of refrigerant accumulated in the outdoor heat exchanger 7 is large, the amount of refrigerant in the refrigerant circuit is insufficient, and a decrease in cooling capacity is caused by an increase in the temperature of refrigerant discharged from the compressor 5. Alternatively, if the amount of refrigerant accumulated in the outdoor heat exchanger 7 is smaller than an appropriate amount, the amount of refrigerant in the refrigerant circuit becomes excessive, and problems such as an increase in pressure of the refrigerant liquid or refrigerant vapor and liquid return occur.

In the above state, as shown in FIG. 2, the pressure sensors 3 provided on the first pipe and the second pipe are provided.
3a, 33b and the thermistor 34 measure the refrigerant temperature and the refrigerant pressure in the refrigerant circuit.
It is sent to the refrigerant amount estimating unit 41 within 0. Same refrigerant amount estimation unit 4
In step 1, the outside air temperature and the temperature value and pressure value of the refrigerant are compared to estimate the amount of refrigerant in the refrigerant circuit.

The estimated value obtained by estimating the amount of refrigerant in the refrigerant circuit by the refrigerant amount estimating unit 41 is used as a refrigerant amount reference value 43 for determining an appropriate amount of refrigerant in the refrigerant circuit.
Is compared to In the cooling operation, when the refrigerant amount determining means 42 determines that the amount of refrigerant in the refrigerant circuit is small, signal information is sent from the refrigerant amount determining means 42 to the drive section 44 as shown in FIG. The drive unit 44 re-controls the opening and closing of each of the electronic expansion valves and the solenoid on-off valves in accordance with the control table during the cooling operation shown in FIG. 4, and as an example, the first state, which has been closed during the 75% cooling operation. Solenoid on-off valve 2
2b is opened. When the solenoid on-off valve 22b is opened, the refrigerant pool remaining in the outdoor heat exchanger 7 that is open and the unused inside the branch pipe 17c passes through the branch pipe 17c and passes through the sixth pipe 17 is removed. After that, it flows into the second pipe 14 in the refrigerant circuit. This prevents the amount of the refrigerant in the refrigerant circuit from recovering to an appropriate value and preventing the multi-room air conditioner from having an insufficient air conditioning capacity. The control performed by the refrigerant amount determining means 42 in other cooling operation states is based on the control table shown in FIG.

Next, the operation of this embodiment during the heating operation will be described. When all the indoor units are operating, the open / close states of the electromagnetic on-off valve and the electronic expansion valve are as shown in FIG. 3 during the 100% operation during the heating operation. When either of the indoor heat exchangers 10 or 11 is stopped from this state, the electromagnetic on-off valves 21b, 22b and 27 are closed, and the heat exchanger 7 is unused. In this state, if the amount of the refrigerant accumulated in the heat exchanger 7 is small, the amount of the refrigerant in the refrigerant circuit becomes excessive, and there is a possibility that the pressure of the refrigerant liquid or refrigerant vapor increases or the liquid returns.

In this state, the pressure sensors 33a, 33b and the thermistors 34, 3
The pressure value and the temperature value of the refrigerant are sent to the refrigerant amount discriminating and estimating unit 41 in the control unit 40 from 5, and the refrigerant amount discriminating unit 42 determines whether the refrigerant amount in the refrigerant circuit is appropriate. You. If it is determined that the amount of refrigerant in the refrigerant circuit is excessive, the refrigerant
If, for example, it is determined that the amount of refrigerant in the refrigerant circuit is excessive during the 75% heating operation, the electromagnetic on-off valve 27 is changed to the open state and excess refrigerant in the refrigerant circuit is not discharged. The amount of the refrigerant flowing into the heat exchanger 7 in the used state and the amount of the refrigerant in the refrigerant circuit is reduced, so that the pressure rise or the liquid return phenomenon of the refrigerant liquid or the refrigerant vapor can be prevented. FIG. 4 shows the control in the other heating state.

[0019]

As described above, in the multi-room air conditioner according to the present invention, a plurality of outdoor heat exchangers having different capacities corresponding to a plurality of indoor heat exchangers having different capacities are provided. A multi-room air conditioner that can supply an appropriate amount of refrigerant in response to all operating conditions of the indoor unit, and if the amount of refrigerant in the refrigerant circuit is insufficient due to the operating condition of the indoor unit The value measured by the pressure sensor and the thermistor is discriminated by the refrigerant amount discriminating means, and the solenoid on-off valve or the electronic expansion valve is opened and closed according to the discrimination standard and control standard, and the refrigerant amount in the refrigerant circuit can be adjusted to the optimum value A multi-room air conditioner.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing one embodiment of a multi-room air conditioner according to the present invention.

FIG. 2 is a control block diagram showing one embodiment of a multi-room air conditioner according to the present invention.

FIG. 3A is a control diagram showing an open / closed state of an electromagnetic on-off valve and an electronic expansion valve during a cooling operation of the multi-room air conditioner according to the present invention. (B) is a control diagram showing an open / closed state of an electromagnetic on-off valve and an electronic expansion valve during a heating operation of the multi-room air conditioner according to the present invention.

FIG. 4 is a control table showing an embodiment of the multi-room air conditioner according to the present invention.

FIG. 5 is a refrigerant amount discrimination reference diagram showing one embodiment of a multi-room air conditioner according to the present invention.

FIG. 6 is a refrigerant circuit diagram showing one embodiment of a conventional multi-room air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outdoor unit 2 Indoor unit 3 Refrigerant division unit 4 Compressor 5 Accumulator 6 First outdoor heat exchanger 7 Second outdoor heat exchanger 8 Third outdoor heat exchanger 9 First indoor heat exchanger 10 Second Indoor heat exchanger 11 Third indoor heat exchanger 12a Electronic expansion valve 12b Electronic expansion valve 12c Electronic expansion valve 13 First pipe 14 Second pipe 15 Third pipe 16 Fourth pipe 17 Sixth pipe 18 Fifth pipe 19 Seventh pipe 20 Eighth pipe 21 First electromagnetic on-off valve 22 Second electromagnetic on-off valve 23 Connection pipe 24 First outdoor heat exchanger discharge side pipe 25 Second and third outdoor heat exchanger discharge side pipe 26 Electronic expansion Valve 27 Electromagnetic on-off valve 28 Electronic expansion valve 29 Branch pipe 30 Branch pipe 31a Electromagnetic on-off valve 31b Electromagnetic on-off valve 31c Electromagnetic on-off valve 32a Electronic expansion valve 32b Electronic expansion valve 32c Electronic expansion valve 3 3a Pressure sensor 33b Pressure sensor 34 Thermistor 35 Thermistor 40 Control unit 41 Refrigerant amount estimating unit 42 Refrigerant amount determining unit 43 Refrigerant amount reference value 44 Drive unit

Claims (2)

[Claims] 1. The compressor has a discharge side connected to a first pipe and a suction side connected to a second pipe. The first pipe is branched into a third pipe and a fourth pipe, and the third pipe is branched in parallel. Via a first solenoid on-off valve, during the cooling operation, respectively connected to the inflow port of the first outdoor heat exchanger, the second outdoor heat exchanger and the inflow side of the third outdoor heat exchanger, Outdoor heat exchanger,
From the outlets of the second outdoor heat exchanger and the third outdoor heat exchanger, connected to the fifth pipe via an electromagnetic on-off valve and an electronic expansion valve,
Inlet of the first outdoor heat exchanger, the second outdoor heat exchanger, and the third outdoor heat exchanger via a second electromagnetic on-off valve and branching in parallel a sixth pipe branched from the second pipe An outdoor unit connected to the first indoor heat exchanger that connects a seventh pipe branching in parallel from the fifth pipe to an inflow side during cooling operation through an electronic expansion valve, and a second chamber. Equipped with an inner heat exchanger and a third indoor heat exchanger, the first indoor heat exchanger, the second indoor heat exchanger and the outlet of the third indoor heat exchanger, the eighth pipe in parallel A plurality of connected indoor units and the same parallel eighth pipe are each further branched, one of the branches is connected to the second pipe via a third solenoid on-off valve, and the other is a fourth solenoid on-off valve. A refrigerant circuit comprising a refrigerant distribution unit connected to the fourth pipe via Simultaneous cooling and heating operation of the plurality of indoor units is enabled by opening and closing the first solenoid on-off valve, the second solenoid on-off valve, the third solenoid on-off valve, the fourth solenoid on-off valve, and the electronic expansion valve according to an operation mode. In the multi-room air conditioner, a heat exchange capacity of the first outdoor heat exchanger is set in accordance with a heat exchange capacity of the first indoor heat exchanger, and the second indoor heat exchanger is set. The heat exchange capacity of the second outdoor heat exchanger is set according to the heat exchange capacity of the third outdoor heat exchanger, and the heat exchange capacity of the third outdoor heat exchanger is set according to the heat exchange capacity of the third indoor heat exchanger. Setting the heat exchange capacity, the first electromagnetic on-off valve and the second electromagnetic on-off valve according to the status of the first indoor heat exchanger, the second indoor heat exchanger and the third outdoor heat exchanger Opening and closing the valves, the first indoor heat exchanger, the second indoor heat exchanger and the third indoor heat exchanger Multi-room air conditioning apparatus proper refrigerant quantity in the exchanger is characterized by being to circulate. 2. The control unit determines an appropriate amount of refrigerant in the refrigerant circuit with respect to an operation state of the first indoor heat exchanger, the second indoor heat exchanger, and the third indoor heat exchanger. A refrigerant amount reference value, a refrigerant amount estimating unit that estimates a refrigerant amount in the refrigerant circuit, based on a measured value and an outside air temperature measured by a pressure sensor and a thermistor for measuring a refrigerant pressure and a refrigerant temperature of the refrigerant circuit. Comparing the refrigerant amount reference value with the estimated value of the refrigerant amount estimating unit, and determining whether the refrigerant amount in the refrigerant amount circuit is too small. 2. The multi-chamber type as claimed in claim 1, further comprising: a drive unit for performing on / off control of an electromagnetic on / off valve, the second electromagnetic on / off valve, another electromagnetic on / off valve, and an electronic expansion valve according to a predetermined control table. Air conditioner.