JP2003194384A - Heat pump type air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type air conditioner which keeps indoor temperature constant by mounting two outdoor heat exchangers and operating one heat exchanger as a defroster, while operating the other as a heater. <P>SOLUTION: This heat pump type air conditioner is composed of: a compressor 12 compressing a coolant; a four-way valve 14 changing over the flow of the coolant from the normal direction to the reverse direction and vice versa; a first outdoor heat exchanger 16 and a second outdoor heat exchanger 18 mounted outdoors, used as a condenser in cooling period and used as an evaporator in heating period; a plurality of indoor heat exchangers 8a, 8b mounted every indoor space, and conducting cooling/heating work; first and second outdoor expansion valves 20, 22 mounted on a coolant piping connecting the first and second outdoor heat exchangers 16, 18 and the indoor heat exchangers 8a, 8b, changing the coolant to a low temperature and low pressure state, and opening/closing the coolant piping; and a control unit 6 controlling first and second outdoor expansion valves 20, 22, and when either one of the first and second outdoor heat exchangers 16, 18 is operated for defrosting, and the other is operated for heating. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner, and more particularly to a heat pump type air conditioner capable of continuously heating a room even during a defrosting operation.

[0002]

2. Description of the Related Art Generally, a heat pump type air conditioner is
An air conditioner capable of simultaneously performing cooling and heating operations, which includes an evaporator and a condenser and can be used as a cooling device, and at the same time, can also be used as a heating device by reversing the flow of refrigerant in a refrigeration cycle. Is.

In the structure of the refrigeration cycle of the conventional heat pump type air conditioner, as shown in FIG. 5, the indoor unit 102 mounted in the room to perform cooling or heating.
And an outdoor unit 104 that is connected to the indoor unit 102 and is mounted outdoors to perform heat exchange work. The indoor unit 102 includes one or more indoor heat exchangers 106 installed in each room to perform cooling and heating operations.

Further, the outdoor unit 104 includes a compressor 108 for compressing a refrigerant, a four-way valve 110 for switching the flow of the refrigerant between a forward direction and a reverse direction, and a condenser used during the cooling operation and an evaporator during the heating operation. And an expansion valve 116 mounted on a refrigerant pipe 114 connecting the outdoor heat exchanger 112 and the indoor heat exchanger 106 to change the refrigerant gas to a low temperature and low pressure. Was configured.

In addition, behind the expansion valve 116,
A liquid receiver 118 that separates the liquid and the airframe is mounted, and a refrigerant pipe that connects the indoor unit 102 and the outdoor unit 104 has a refrigerant pipe supplied to the indoor unit 102 and a refrigerant discharged to the outdoor unit. The opening / closing valves 120 that perform the opening / closing operation were mounted respectively.
Further, an accumulator 122 for converting into a refrigerant in a fuselage state is mounted on one side of the compressor 108.
An oil separator 124 was attached to the discharge side of 08.

The operation of the conventional heat pump type air conditioner thus constructed will be described below. First, during the cooling operation, the refrigerant gas compressed by the compressor 108 flows into the outdoor heat exchanger 112 through the four-way valve 110, and then passes through the expansion valve 116 to be changed into a low-temperature and low-pressure refrigerant state so that the indoor heat exchange is performed. Flow into the vessel 106. The refrigerant gas evaporated from the indoor heat exchanger 106 cools the room while exchanging heat with the room air.
It is circulated while being sucked into the compressor 108 through the four-way valve 110.

In the heating operation, on the contrary, the flow of the refrigerant is switched to the opposite direction by the four-way valve 110, and the refrigerant gas discharged from the compressor 108 passes through the four-way valve 110 and the indoor heat exchanger. The interior of the room is heated while being condensed while being introduced into 106 and exchanging heat with the room air, and then the refrigerant passing through the indoor heat exchanger 106 is changed into a low temperature and low pressure refrigerant state while passing through the expansion valve 116. Thus, it is evaporated while passing through the outdoor heat exchanger 112. Then, the refrigerant gas evaporated in this way was circulated while being sucked into the compressor 108 via the four-way valve 110 again.

When the defrosting operation of the heat pump type air conditioner is performed as described above, the outdoor heat exchanger 112 is used as a condenser by performing a cooling operation for a predetermined period by a method of driving a reverse cycle. As a result, a method of melting the frost formed on the outdoor heat exchanger 112 by the heat of condensation is generally used.

[0009]

However, in such a conventional heat pump type air conditioner, since the heating operation is stopped when the defrosting operation is performed, the temperature of the room falls and There was an inconvenience that it adversely affected the environment. Further, when the conventional heat pump type air conditioner is a multi-type in which an indoor heat exchanger is installed for each room in the room, the amount of refrigerant supplied to each indoor heat exchanger is the same, and each indoor heat exchanger is Since the heat exchange capacities are the same, there is an inconvenience that the cooling and heating capacities cannot be varied depending on the size of each room.

The present invention has been made in view of such conventional problems. Two outdoor heat exchangers are mounted, one heat exchanger is performing defrosting operation, and the other one is heating operation. An object of the present invention is to provide a heat pump type air conditioner capable of maintaining a constant indoor temperature by carrying out the operation. Further, in the case of a multi-type having a plurality of indoor heat exchangers, it is possible to provide a heat pump type air conditioner capable of improving cooling and heating performance by varying the heat exchange capacity of each indoor heat exchanger according to the size of each room. With the goal.

[0011]

In order to achieve such an object, in a heat pump type air conditioner according to the present invention, a compressor for compressing a refrigerant and a flow of the refrigerant are switched between a forward direction and a reverse direction. A four-way valve, a first outdoor heat exchanger and a second outdoor heat exchanger that are installed outdoors and are used for a condenser during cooling, and are used for an evaporator during heating, and are installed for each indoor space to cool down. / A plurality of indoor heat exchangers that perform the function of heating and refrigerant pipes connected between the first and second outdoor heat exchangers and the indoor heat exchangers are respectively mounted to change the refrigerant to a low temperature and low pressure. The first and second outdoor expansion valves for opening and closing the refrigerant pipe by controlling the first and second outdoor expansion valves, and one of the first and second outdoor heat exchangers is performing defrosting operation. Control to heat one of the other when it is Unit, and a plurality of indoor expansion valves mounted on the indoor-side refrigerant pipe so as to adjust the amounts of refrigerant respectively flowing into the plurality of indoor heat exchangers differently. Characterize.

The first port of the four-way valve is connected to the discharge side of the compressor, the second port is connected to each of the indoor heat exchangers by a first refrigerant pipe, and the third port is connected to the third port. Second and third refrigerant pipes are connected to the first and second outdoor heat exchangers, respectively, and the fourth port is connected to the suction side of the compressor, so that the first port and the third port are connected during cooling. And the second port and the fourth port are communicated with each other, and during heating, the first port and the second port and the third port and the fourth port are communicated with each other. Characterize.

Further, the first outdoor heat exchanger is connected to the four-way valve by a second refrigerant pipe, is connected to the indoor heat exchanger by a fourth refrigerant pipe, and is connected to the fourth refrigerant pipe and the four-way valve. A sixth refrigerant pipe is connected between the second ports, and a first valve that opens and closes the sixth refrigerant pipe according to an electric signal transmitted from the control unit is attached to the sixth refrigerant pipe. To do. The first valve may be a solenoid type that opens the sixth refrigerant pipe in response to an electric signal applied from the control unit.

The second outdoor heat exchanger is connected to the four-way valve by a third refrigerant pipe and is connected to the indoor heat exchanger by a fifth refrigerant pipe, and the fifth refrigerant pipe and the four-way valve are connected to each other. A seventh refrigerant pipe is connected between the second ports, and a second valve that opens and closes the seventh refrigerant pipe according to an electric signal applied from the control unit is attached to the seventh refrigerant pipe. To do. The second valve may be a solenoid type that opens the seventh refrigerant pipe according to an electric signal applied from the control unit.

Further, the control unit operates the first valve to open the sixth refrigerant pipe and operate the first outdoor expansion valve to operate the fourth outdoor refrigerant during defrosting operation of the first outdoor heat exchanger. It is characterized in that it is configured to close the piping. Also, the control unit is
During the defrosting operation of the second outdoor heat exchanger, the second valve is operated to open the seventh refrigerant pipe, and the second outdoor expansion valve is operated to close the fifth refrigerant pipe. Is characterized by.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the heat pump type air conditioner according to the present invention, as shown in FIG. 1, an indoor unit 2 that is mounted indoors and performs a cooling or heating operation,
An outdoor unit 4 that is connected to the indoor unit 2 by a refrigerant pipe and is mounted outdoors to perform a heat exchange action; a control unit (see FIG. 2) 6 that controls a cooling operation, a heating operation, and a defrosting operation, respectively; It is configured to include.

Further, the indoor unit 2 includes a plurality of indoor heat exchangers 8a and 8b mounted in each space of the room, and the indoor heat exchangers 8a and 8b for changing the refrigerant into a low temperature and low pressure state. And a plurality of indoor expansion valves 10a, 10b for adjusting the flow rate of the refrigerant supplied to the.

Further, the outdoor unit 4 includes a compressor 12 for compressing a refrigerant, a four-way valve 14 for switching the flow of the refrigerant between a forward direction and a reverse direction, a condenser during cooling, and an evaporator during heating. First and second outdoor heat exchangers 16 and 18 used and the first and second outdoor heat exchangers 1
First and second outdoor expansion valves 20, 22 which are respectively attached to the refrigerant pipes connecting the heat exchangers 6, 18 and the indoor heat exchangers 8a, 8b to change the refrigerant gas to a low temperature and low pressure and to open and close the refrigerant pipes; , Is included. or,
An accumulator 24 that sucks a refrigerant is mounted on the suction side of the compressor 12, and an oil separator 26 is mounted on the discharge side of the compressor 12.

The first and second outdoor heat exchangers 16,
A liquid receiver 28 is connected to the refrigerant pipe between the heat exchanger 18 and the indoor heat exchangers 8a and 8b. Also, the four-way valve 14
Is the first port 3 connected to the discharge side of the compressor 12.
0, the second port 32 connected to the indoor heat exchangers 8a and 8b, and the first and second outdoor heat exchangers 16 and 18
And a fourth port 36 connected to the suction side of the compressor 12 are included.

The four-way valve 14 thus constructed is
During the cooling operation, the second port 32 and the fourth port 36 and the first port 30 and the third port 34 are communicated with each other to flow the refrigerant in the forward direction, and during the heating operation, the first port 3
0 and 2 port 32, 3rd port 34 and 4th port 36
To communicate with each other to cause the refrigerant to flow in the opposite direction. Also, the second port 32 of the four-way valve 14 and the indoor heat exchanger 8
The a and 8b are connected by a first refrigerant pipe 40, the third port 34 and the first outdoor heat exchanger 16 are connected by a second refrigerant pipe 42, and the third port 34 and the second outdoor heat are connected. The exchangers 18 are connected by a third refrigerant pipe 44.

The first outdoor heat exchanger 16 and the second outdoor heat exchanger 18 are connected to the indoor heat exchangers 8a and 8b by fourth and fifth refrigerant pipes 46 and 48, respectively. A first outdoor expansion valve 20 is attached to the fourth refrigerant pipe 46, and a second outdoor expansion valve 22 is attached to the fifth refrigerant pipe 48.
Is installed. Also, the fourth refrigerant pipe 46 and the fifth refrigerant pipe 48 are joined together and connected to the liquid receiver 28, and the liquid receiver 28 and the indoor heat exchangers 8a, 8b.
A plurality of indoor expansion valves 1 are provided in each refrigerant pipe connected between them.
0a and 10b are attached respectively.

Further, on-off valves 52 for connecting and disconnecting the flow of the refrigerant are attached to the two pipes which are connected to the indoor heat exchangers 8a and 8b and suck and discharge the refrigerant. Further, the fourth refrigerant pipe 46 and the first refrigerant pipe 40 are connected by a sixth refrigerant pipe 54, and the fifth refrigerant pipe 48 and the first refrigerant pipe 48 are connected to each other.
The seventh refrigerant pipe 56 communicates between the refrigerant pipes 40. Further, the sixth refrigerant pipe 54 is connected to the sixth refrigerant pipe 5.
4, a first valve 58 for opening and closing the fourth refrigerant pipe 56 is attached to the seventh refrigerant pipe 56, and a second valve 60 for opening and closing the seventh refrigerant pipe 56 is attached to the seventh refrigerant pipe 56. At this time, the first valve 58 and the second valve 60 are supplied with an electric signal from a control unit 6 (see FIG. 2), which will be described later.
The solenoid type is configured to open the sixth refrigerant pipe 54 and the seventh refrigerant pipe 56.

In the heat pump type air conditioner according to the present invention, as shown in FIG. 2, the operation selecting section 70 for the user to operate the cooling or heating operation, and the first outdoor heat exchanger 1.
The first to detect whether or not frost is frosted over a set value in 6
A sensing unit 72, and a second sensing unit 74 that senses whether or not frost has formed on the second outdoor heat exchanger 18 at a set value or more,
The control unit 6 that performs the cooling operation, the heating operation, and the defrosting operation, respectively, according to the signals transmitted from the operation selecting unit 70, the first and second sensing units 72 and 74, is additionally configured. .

In addition, the first and second sensing units 72 and 74
Using a temperature sensor, the first outdoor heat exchanger 1
6 and the second outdoor heat exchanger 18 are frosted, the control unit 6 operates the four-way valve 14 by operating the operation selection unit 70 to perform a cooling / heating conversion operation. According to the signals applied from the first sensing unit 72 and the second sensing unit 74, the first outdoor heat exchanger 20
One of the second outdoor heat exchanger 22 is controlled to perform the defrosting operation and the other is controlled to perform the heating operation.

When the user operates the operation selecting section 70 to set the cooling / heating capacity of each of the indoor heat exchangers 8a, 8b, the control unit 6 controls the indoor expansion valve 10a, The opening amount of 10b is adjusted to adjust the flow rate of the refrigerant supplied to each indoor heat exchanger 8a, 8b.

The operation of the heat pump type air conditioner according to the present invention constructed as above will be described below.
First, during the cooling operation, as shown in FIG. 1 and FIG.
When the user operates the operation selection unit 70 to select the cooling operation, the control unit 6 operates the four-way valve 1
By operating 4 to make the second port 32 and the fourth port 36 and the first port 30 and the third port 34 communicate with each other, the first valve 58 and the second valve 60 are maintained in the closed state.

When the compressor 12 is driven in such a state, the compressed refrigerant causes the first refrigerant of the four-way valve 14 to flow.
It flows into the port 30 and is discharged to the third port 34, and flows into the first outdoor heat exchanger 16 and the second outdoor heat exchanger 18 through the second refrigerant pipe 42 and the third refrigerant pipe 44, respectively, to generate heat. The refrigerant that has been exchanged and the heat exchange has been completed is discharged to the fourth refrigerant pipe 46 and the fifth refrigerant pipe 48,
While passing through the first and second outdoor expansion valves 20 and 22, the refrigerant is changed to a low-temperature low-pressure refrigerant state, and each indoor heat exchanger 8
a, 8b. Then, the indoor heat exchanger 8
The refrigerant gas evaporated from a and 8b cools the room while exchanging heat with the room air, and then flows through the first refrigerant pipe 40 into the second port 32 of the four-way valve and is discharged to the third port 34. It is then circulated while flowing into the compressor 12 and being compressed again.

When the user operates the operation selecting section 70 to select the heating operation, the first port 30 and the second port 32 of the four-way valve are controlled by the control unit 6 as shown in FIG. The third port 34 and the fourth port 36 are communicated with each other so that the refrigerant flows in the opposite direction. Even at this time, the first valve 58 and the second valve 60 maintain the closed state.

Then, the refrigerant compressed by driving the compressor 12 flows into the first port 30 of the four-way valve, is discharged to the second port 32, and passes through the first refrigerant pipe 40 to the indoor heat exchange. It is condensed while flowing into the vessels 8a and 8b. Then, the room is heated while exchanging heat with the room air, and the refrigerant passing through the room heat exchangers 8a and 8b passes through the room expansion valves 10a and 10b and the first and second room expansion valves 10a and 10b. While changing to a low temperature and low pressure refrigerant state, the fourth and fifth refrigerant pipes 46, 4
It is evaporated while passing through the first and second outdoor heat exchangers 16 and 18. The refrigerant thus evaporated flows into the third port 34 of the four-way valve 110 again, is discharged to the fourth port 36, and is sucked into the compressor 12 and circulated.

In such a cooling / heating operation, when a plurality of indoor heat exchangers 8a, 8b mounted in each space of the room are changed in cooling / heating capacity so as to fit the area of the indoor space, it is used. The operator operates the operation selection unit 70 to select the heat exchange capacity of each of the indoor heat exchangers 8a and 8b, so that the control unit 6 causes the indoor expansion valves 10a and 10b to respond to the signal from the operation selection unit 70. The cooling / heating capacity is adjusted by adjusting the opening / closing amount of the refrigerant to adjust the flow rate of the refrigerant supplied to each indoor heat exchanger 8a, 8b.

Further, in the usage state of the heat pump type air conditioner according to the present invention during the defrosting operation, as shown in FIG. 4, the control unit 6 includes the first sensing section 72 and the second sensing section. When it is determined that any one of the outdoor heat exchangers receives the signal transmitted from H.74 and is in a state in which frost has been set to a preset value or more, the outdoor heat exchanger with frost Performs defrosting operation and controls other outdoor heat exchangers to perform heating operation.

That is, during the heating operation, when it is determined that the first outdoor heat exchanger 16 needs the defrosting operation by the signal applied from the first sensing unit 72, the control unit 6 causes the first outdoor heat exchanger 16 to perform the defrosting operation. The 1st valve 58 is operated to operate the sixth valve.
When the refrigerant pipe 54 is opened and the first outdoor expansion valve 20 is operated to close the fourth refrigerant pipe 46, the compressor 1
The refrigerant compressed in 2 flows into the second port 3 of the four-way valve 14.
2 through the first refrigerant pipe 40 to the first and second
The heat is supplied to the indoor heat exchangers 8a and 8b, and the second port 3
A part of the refrigerant discharged to the second passage is condensed while being supplied to the first outdoor heat exchanger 16 through the sixth refrigerant pipe 54, and the defrosting action is performed. Next, the refrigerant discharged after completing the defrosting action of the first outdoor heat exchanger 16 is the second
The compressor 12 is again passed through the refrigerant pipe 42 and the four-way valve 14.
Is flowed into. At this time, the second outdoor heat exchanger 18 is
A normal heating operation is performed as in the heating operation described above.

As described above, even when the first outdoor compressor 16 performs the defrosting operation, the second outdoor heat exchanger 18
In order to perform normal heating operation, the indoor heating operation is continuously performed. Then, when it is determined that the defrosting operation of the second outdoor heat exchanger 18 is necessary, the control unit 6 operates the second valve 60 to apply power to the seventh refrigerant pipe 56. Opening, the second outdoor expansion valve 60 is operated to close the fifth refrigerant pipe 48.

Next, the refrigerant compressed by the compressor 12 is discharged to the second port 32 of the four-way valve, is supplied to the indoor heat exchangers 8a and 8b through the first refrigerant pipe 40, and the second refrigerant is also supplied. Part of the refrigerant discharged to the port 32 passes through the seventh refrigerant pipe 56 and the second outdoor heat exchanger 18
While being supplied to, it is condensed and performs a defrosting action. The refrigerant discharged after the defrosting action of the second outdoor heat exchanger 18 is discharged is the third refrigerant pipe 44 and the four-way valve 16.
And then flows into the compressor 12 again. At this time, the first outdoor compressor performs a normal heating operation as in the heating operation described above.

[0035]

As described above, in the heat pump type air conditioner according to the present invention, each indoor heat exchanger is provided with an indoor expansion valve, and the opening amount of each indoor expansion valve is adjusted. Then, there is an effect that the cooling / heating capacity suitable for the size of the space in each room can be varied by adjusting the flow rate of the refrigerant supplied to each indoor heat exchanger.
When one outdoor heat exchanger is in the defrosting operation with two outdoor heat exchangers, the other outdoor heat exchanger performs the heating operation to maintain the indoor temperature constant. The effect is that the indoor environment can be maintained more comfortably.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a refrigeration cycle of a heat pump type air conditioner according to the present invention.

FIG. 2 is a block diagram showing a control device for a heat pump type air conditioner according to the present invention.

FIG. 3 is an operation diagram showing a usage state of the refrigeration cycle of the heat pump type air conditioner according to the present invention.

FIG. 4 is an operation diagram showing a usage state of the refrigeration cycle of the heat pump type air conditioner according to the present invention.

FIG. 5 is a configuration diagram showing a refrigeration cycle of a conventional heat pump type air conditioner.

[Explanation of symbols]

2 ... Indoor unit 4 ... Outdoor unit 6 ... Control unit 8a, 8b ... Indoor heat exchanger 10a, 10b ... Indoor expansion valve 12 ... Compressor 14 ... Four-way valve 16 ... First outdoor heat exchanger 18 ... Second outdoor heat exchanger 20 ... First outdoor expansion valve 22 ... Second outdoor expansion valve 30, 32, 34, 36 ... First, second, third, fourth port 40 ... First refrigerant pipe 42 ... Second refrigerant pipe 44 ... Third refrigerant pipe 46 ... Fourth refrigerant pipe 48 ... Fifth refrigerant pipe 54 ... Sixth refrigerant pipe 56 ... Seventh refrigerant pipe 58 ... 1st valve 60 ... Second valve 70 ... Operation selection section 72 ... First sensing unit 74 ... Second sensing unit

Claims (10)

[Claims] 1. A compressor for compressing a refrigerant, a four-way valve for switching the flow of the refrigerant in a forward direction or a reverse direction, and an outdoor mounted valve used for a condenser during cooling and used for an evaporator during heating. A first outdoor heat exchanger and a second outdoor heat exchanger, a plurality of indoor heat exchangers mounted in each indoor space to perform cooling / heating operations, the first and second outdoor heat exchangers, and First and second outdoor expansion valves, which are respectively attached to refrigerant pipes connecting between the indoor heat exchangers, to change the refrigerant to low temperature and low pressure to open and close the refrigerant pipes, and the first and second outdoor expansion valves. A control unit for controlling and heating one of the first and second outdoor heat exchangers when one of them is in the defrosting operation. A heat pump type air conditioner. 2. The heat pump type air conditioner is further provided with a plurality of indoor expansion valves mounted on a refrigerant pipe on an indoor side so as to adjust the amount of refrigerant flowing into the plurality of indoor heat exchangers differently. The heat pump type air conditioner according to claim 1, wherein the heat pump type air conditioner is included. 3. The first port of the four-way valve is connected to the discharge side of the compressor, the second port is connected to each of the indoor heat exchangers by a first refrigerant pipe, and the third port is
Second and third refrigerant pipes are connected to the first and second outdoor heat exchangers, respectively, and the fourth port is connected to the suction side of the compressor so that the first port and the third port are connected to each other during cooling. The second port and the fourth port are operated to communicate with each other, and the first port and the second port are operated during heating.
The heat pump type air conditioner according to claim 1, wherein the heat pump type air conditioner is operated so that the ports and the third port and the fourth port communicate with each other. 4. The first outdoor heat exchanger is connected to the four-way valve by a second refrigerant pipe, is connected to the indoor heat exchanger by a fourth refrigerant pipe, and is connected to the fourth refrigerant pipe and the four-way valve. A sixth refrigerant pipe is connected between the second ports, and the sixth refrigerant pipe is equipped with a first valve that opens and closes the sixth refrigerant pipe in response to an electric signal transmitted from the control unit. Claim 1
The heat pump type air conditioner described. 5. The heat pump type air conditioner according to claim 4, wherein the first valve is of a solenoid type that opens the sixth refrigerant pipe in response to an electric signal applied from the control unit. 6. The second outdoor heat exchanger is connected to the four-way valve by a third refrigerant pipe, is connected to the indoor heat exchanger by a fifth refrigerant pipe, and is connected to the fifth refrigerant pipe and the four-way valve. A seventh refrigerant pipe is connected between the second ports, and a second valve that opens and closes the seventh refrigerant pipe according to an electric signal applied from the control unit is attached to the seventh refrigerant pipe. Claim 1 characterized by
The heat pump type air conditioner described. 7. The heat pump type air conditioner according to claim 6, wherein the second valve is of a solenoid type that opens the seventh refrigerant pipe in response to an electric signal applied from the control unit. . 8. The control unit comprises the first
When the outdoor heat exchanger is in the defrosting operation, the first valve is operated to open the sixth refrigerant pipe, and the first outdoor expansion valve is operated to close the fourth refrigerant pipe. The heat pump type air conditioner according to claim 4. 9. The control unit includes the second unit.
During the defrosting operation of the outdoor heat exchanger, the second valve is operated to open the seventh refrigerant pipe, and the second outdoor expansion valve is operated to close the fifth refrigerant pipe. The heat pump type air conditioner according to claim 6. 10. A compressor for compressing a refrigerant, a four-way valve for switching the flow of the refrigerant between a forward direction and a reverse direction, and an outdoor mounted valve used as a condenser during cooling and used as an evaporator during heating. A first outdoor heat exchanger and a second outdoor heat exchanger; a plurality of indoor heat exchangers mounted in each indoor space to perform cooling / heating operations; and the first and second outdoor heat exchangers First and second outdoor expansion valves, which are respectively attached to the refrigerant pipes connecting the indoor heat exchangers to open and close the refrigerant pipes, and the first and second outdoor expansion valves and the four-way valve are controlled to control the first and second outdoor expansion valves. A control unit for heating one of the first and second outdoor heat exchangers when one of them is in defrosting operation, and a plurality of indoor heat exchangers mounted on the indoor refrigerant pipes. Adjust the amount of refrigerant flowing into each A heat pump type air conditioner characterized by including a plurality of indoor expansion valves.