JP2001241798A - Multizone air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To independently perform heating and cooling operations for a plurality of indoor machines by a simple structure in an air conditioner having a plurality of indoor machines for one outdoor machine. SOLUTION: Two indoor machines A and B arranged in parallel are connected to one outdoor machine. A bypass 14 is provided so as to stride over an outdoor heat exchanger 2 from fourth selector valves 13a and 13b provided in piping for connecting each of the indoor machines A and B to the outdoor heat exchanger 2 to a second selector valve 11 between a compressor 1 and the outdoor heat exchanger 2. When simultaneous heating and cooling operations are carried out, a refrigerant discharged from the compressor 1 is fed to the indoor machine A for performing a heating operation to heat a room. The refrigerant from the indoor machine A reaches the outdoor heat exchanger 2 via the bypass pipe 14 to radiate heat, and passes through an expansion valve 3b corresponding to the indoor machine B for performing a cooling operation to reduce its pressure. The pressure reduced refrigerant reaches the indoor machine B to cool the room.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a multi-type air conditioner comprising one outdoor unit and a plurality of indoor units.

[0002]

2. Description of the Related Art A first conventional example of a conventional multi-type air conditioner capable of performing simultaneous cooling and heating operations is disclosed in Japanese Patent Application Laid-Open No. 61-1 / 1986.
It is disclosed in 38064. In this air conditioner, the same number of outdoor heat exchangers as the indoor units are arranged, and the flow of the refrigerant to each indoor unit is controlled by the switching mechanism, so that each room is independently cooled and heated.

A second conventional example is disclosed in Japanese Patent Application Laid-Open No.
The air conditioner disclosed in Japanese Patent Publication No. 9 uses a single flow controller provided with a gas-liquid separator in addition to one outdoor unit and a plurality of indoor units. During simultaneous cooling and heating operation, if there are many indoor units during cooling operation, the liquid refrigerant and gas refrigerant are separated by the gas-liquid separator, and the gas refrigerant passes through the indoor unit during heating operation and becomes liquid refrigerant. And the liquid refrigerant that has passed through the gas-liquid separator, and are allowed to pass through the indoor unit during the cooling operation. When there are many indoor units in the heating operation, the gas refrigerant passes through the indoor unit in the heating operation to become a liquid refrigerant, and passes through the indoor unit in the cooling operation.

Further, as a third conventional example, Japanese Patent Laid-Open No.
In the air conditioner disclosed in Japanese Patent No. 2417, two indoor units are connected to one outdoor unit. Simultaneous cooling and heating operation is possible with a simple structure using a switching valve and a check valve. I have to.

[0005]

However, in the above-mentioned first conventional example, the heat exchangers are required for the outdoor units by the number of the indoor units, and the switching mechanism is increased accordingly. Would. Further, in the second conventional example, the provision of the branch flow controller increases the number of solenoid valves for switching the flow of the refrigerant, and the control according to the operation becomes complicated.
Furthermore, in the third conventional example, piping is complicated to accommodate three or more indoor units, and a simple structure cannot be achieved.

In view of the above, the present invention has been made in view of the above, and a plurality of indoor units can cope with a single outdoor heat exchanger with a simple structure. The purpose is to provide.

[0007]

Means for Solving the Problems According to the present invention, a plurality of indoor units each having an indoor heat exchanger and arranged in parallel include a compressor, a plurality of switching valves, an outdoor heat exchanger, and an indoor heat exchanger. When connected to an outdoor unit having the same number of flow control valves as the unit, each from the intermediate point between each flow control valve and the outdoor heat exchanger provided in the pipe connecting each indoor unit and the outdoor heat exchanger The branched bypass pipe is connected to an intermediate point between the discharge side of the compressor and the outdoor heat exchanger so as to straddle the outdoor heat exchanger, and a switching valve is provided at each intermediate point.

By providing this bypass pipe, it is possible to switch the flow direction of the refrigerant to each indoor unit, and it is possible to perform cooling and heating independently for each indoor unit.

That is, when only the cooling operation is performed, the refrigerant discharged from the compressor is depressurized by passing through a flow control valve in a pipe connected to each indoor unit via an outdoor heat exchanger, and is conveyed to each indoor unit. When it reaches, it cools each room.
Thereafter, the refrigerant returns to the compressor through the indoor heat exchanger. When performing only the heating operation, the refrigerant discharged from the compressor is:
Reach each indoor unit and heat each room. Thereafter, the refrigerant returns to the compressor via the flow control valve and the outdoor heat exchanger.

Next, when simultaneous cooling and heating operations are performed, the refrigerant discharged from the compressor is first sent to an indoor unit that performs the heating operation to heat the room. At the intermediate point between the indoor unit and the outdoor heat exchanger, the flow direction of the refrigerant is switched by the switching valve so as to pass through the bypass pipe, and the refrigerant from the indoor unit reaches the outdoor heat exchanger through the bypass pipe. Is dissipated. Then, the air flows from the outdoor heat exchanger to a pipe leading to the indoor unit that performs the cooling operation, passes through the flow control valve, is depressurized, further reduces the temperature of the refrigerant, and reaches the indoor unit to perform indoor cooling. Thereafter, the refrigerant returns to the compressor. In this way, by switching the flow direction of the refrigerant by the bypass pipe straddling the outdoor heat exchanger, the refrigerant passes through the outdoor heat exchanger and the flow control valve, and the temperature of the refrigerant can be significantly reduced, Sufficient cooling capacity can be obtained.

A flow control valve and two switching valves are added to the indoor unit, and a bypass pipe is provided so that one outdoor unit can be used. Therefore, even if the number of indoor units increases, the overall configuration is not complicated, and independent cooling and heating for each indoor unit can be performed with a simple configuration. In addition, since the flow control valve and the switching valve are provided in the outdoor unit, even when the indoor unit is added, the flow control valve and the switching valve may be installed in the outdoor unit and the piping with the indoor unit may be performed. It becomes easy and can easily cope with the expansion of indoor units.

[0012]

FIG. 1 shows a multi-type air conditioner according to an embodiment of the present invention. This air conditioner is composed of one outdoor unit and two indoor units A and B, and performs both or only one cooling operation, both or only one heating operation, one cooling operation, and the other cooling operation. Can perform simultaneous heating and cooling operation of heating operation.

The indoor units A and B are arranged in parallel, and the outdoor unit has a compressor 1, an outdoor heat exchanger 2, two expansion valves 3a and 3b as flow control valves, and a plurality of switching valves. Each of the indoor units A and B has an indoor heat exchanger 4 and a blower (not shown). The switching valve is a three-way switching valve. Here, the three-way switching valve is a valve having three ports, for example,
Assuming that the port has a port, the port is closed when the port is in communication, and is closed when the port is in communication with the port. The expansion valves 3a, 3b
It is a valve that can be opened and closed, and can adjust the flow rate of the refrigerant.

Then, a first connection pipe 5 from the discharge side of the compressor 1 to the indoor heat exchanger 4 of the indoor unit A via the outdoor heat exchanger 2 and the expansion valve 3a, and from the indoor heat exchanger 4 to the compressor 1 A second connection pipe 6 reaching the suction side of the compressor, and a third intermediate point between a first intermediate point between the discharge side of the compressor 1 and the outdoor heat exchanger 2 and the discharge side of the compressor 1 and the indoor heat exchanger 4. Third connection pipe 7 for connecting up to the point
And a fourth connection pipe 8 that connects a second intermediate point between the discharge side of the compressor 1 and the outdoor heat exchanger 2 to a suction side of the compressor 1. The connection pipes 5 to 8 form a main pipe connecting the outdoor unit and the indoor units A and B, and a refrigerant cycle is formed. At each of the first to third intermediate points,
First to third switching valves 10, 11, 12a, 12b, respectively
Is provided.

The indoor unit B is similarly connected to the outdoor unit by a main pipe. That is, the first connection pipe 5 and the third connection pipe 7 are branched into two parts in the middle and connected to the indoor units A and B, respectively. The second connection pipe 6 is connected to the compressor 1 as a single pipe in which pipes from the indoor units A and B join together on the way. The fourth connection pipe 8 joins the second connection pipe 6 on the way.

Here, in order to perform simultaneous cooling and heating operations, a fourth switching valve 1 is connected between the outdoor heat exchanger 2 and the expansion valves 3a and 3b.
3a and 13b are provided, and a bypass pipe 14 for connecting the switching valves 13a and 13b to the second switching valve 11 is provided. The bypass pipe 14 is connected to the second switching valve 11 by connecting pipes from the fourth switching valves 13a and 13b corresponding to the indoor units A and B on the way, and connecting the outdoor heat exchanger 2 to the outside. It is straddling.

The compressor 1, the blower, the expansion valves 3a, 3
b, the first to fourth switching valves 10, 11, 12a, 12b, 1
The control devices 3a and 13b are driven and controlled by a control device including a microcomputer in accordance with an operation selected from among a cooling operation, a heating operation, and a simultaneous cooling and heating operation, and the direction in which the refrigerant flows is switched by a switching valve.

First, when only the cooling operation is performed, each switching valve is switched as shown by the solid line in FIG. 1, and the refrigerant flows as shown by the solid arrow. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 passes through the first connection pipe 5 and the indoor units A and B
Reach That is, the first switching valve 10 and the second switching valve 11
And cooled by the outdoor heat exchanger 2 to become a liquid refrigerant.
The pressure is reduced by the expansion valves 3a, 3b corresponding to the operating indoor units A, B through the switching valves 13a, 13b. The refrigerant is heated by the indoor heat exchanger 4 to become a low-pressure gas refrigerant, cools the room, and the third switching valves 12 a and 12 b of the second connection pipe 6.
And returns to the compressor 1. When there are indoor units A and B that are not operating, the expansion valves 3a and 3b are fully closed, and no refrigerant flows to the indoor heat exchanger 4 in the room.

In the case of only the heating operation, each switching valve is switched as shown by a broken line in FIG. 1, and the refrigerant flows as shown by a broken arrow. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 reaches the indoor units A and B through the third connection pipe 7.
That is, it passes through the first switching valve 10, passes through the third switching valve 12a,
After passing through 12b, it becomes a liquid refrigerant in the indoor heat exchanger 4 to heat the room. And when returning through the first connection pipe 5,
The pressure is reduced by the expansion valves 3a, 3b, and the fourth switching valves 13a, 13
b, and becomes a low-pressure gas refrigerant in the outdoor heat exchanger 2,
The second switching valve 11 returns to the compressor 1 through the fourth connection pipe 8. When there are indoor units A and B that are not operating, the expansion valves 3a and 3b are fully closed, and no refrigerant flows to the indoor heat exchanger 4 in the room.

In the simultaneous cooling and heating operation, for example, when the indoor unit A performs the heating operation and the indoor unit B performs the cooling operation, each switching valve is switched as shown by a solid line in FIG. The gas refrigerant passes through the third connection pipe 7 via the first switching valve 10, passes through the third switching valve 12a on the indoor unit A side, and reaches the indoor unit A. Then, in the indoor unit A, it becomes a liquid refrigerant in the indoor heat exchanger 4, heats the room, and then passes through the expansion valve 3a in a fully open state, from the fourth switching valve 13a to the second switching valve 13a, through the bypass bus 14, and to the second switching. It flows to the outdoor heat exchanger 2 via the valve 11. After the liquid refrigerant is further cooled in the heat exchanger 2, the liquid refrigerant passes through the first connection pipe 5 on the indoor unit B side, passes through the fourth switching valve 13b, and is decompressed by the expansion valve 3b.
Reach In the indoor unit B, the refrigerant becomes a low-pressure gas refrigerant in the indoor heat exchanger 4, and cools the room. Thereafter, the flow returns to the compressor 1 through the second connection pipe 6 via the third switching valve 12b.

In the above-described air conditioner, the number of the indoor units is two, but it is possible to easily cope with three or more indoor units. For example, when there are three indoor units, three indoor units A, B, and C are arranged in parallel during the refrigerant cycle, as shown in FIG. In this case, there are three expansion valves 3a, 3b, 3c corresponding to the indoor units A, B, C, the first connection pipe 5 and the third connection pipe 7 are branched into three, and the second connection pipe 6 is The three pipes from each of the indoor units A, B, and C merge into one, and the bypass pipe 14 also joins the three pipes from each of the indoor units A, B, and C along the way into one. And is connected to the second switching valve 11. As described above, when the number of indoor units increases by one, two switching valves, one expansion valve, and a pipe connecting them may be provided in the outdoor unit, which can be easily coped with.

Here, the flow of the refrigerant in the case of only the cooling operation and the case of only the heating operation is the same as described above, and will not be described. In the case of simultaneous cooling and heating operation, for example, when the indoor unit A performs the heating operation and the indoor unit B and the indoor unit C perform the cooling operation, each switching valve is switched as shown by the solid line in FIG. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 passes through the first switching valve 10 and
After passing through the switching valve 12a, it becomes a liquid refrigerant in the indoor heat exchanger 4 of the indoor unit A, performs heating, and fully expands the expansion valve 3a,
The liquid refrigerant is further cooled in the outdoor heat exchanger 2 via the fourth switching valve 13a and the second switching valve 11. Then, indoor unit B,
Passing through the fourth switching valves 13b and 13c corresponding to C, respectively, is decompressed by the expansion valves 3b and 3c, becomes a low-pressure gas refrigerant in the indoor heat exchanger 4, and cools the room where the indoor units B and C are located. . Thereafter, the flow returns to the compressor 1 via the third switching valves 12b and 12c corresponding to the indoor units B and C.

If the indoor unit A and the indoor unit B are in the heating operation and the indoor unit C is in the cooling operation, the third switching valve 12b and the fourth switching valve 13b corresponding to the indoor unit B are switched from the above case. Good. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 passes through the first switching valve 10, passes through the third switching valves 12 a and 12 b corresponding to the indoor units A and B, and passes through the indoor heat exchanger 4 as a liquid refrigerant. , And heats the room with the indoor units A and B. Thereafter, the refrigerant passes through the expansion valves 3a, 3b and the fourth switching valves 13a, 13b in the fully opened state corresponding to the indoor units A, B, passes through the second switching valve 11, and is further cooled in the outdoor heat exchanger 2 by the outdoor heat exchanger 2. Passing through the fourth switching valve 13c corresponding to the indoor unit C,
The pressure is reduced by the expansion valve 3c, becomes a low-pressure gas refrigerant in the indoor heat exchanger 4, and cools the room where the indoor unit C is located. Indoor unit C
Then, the process returns to the compressor 1 via the third switching valve 12c corresponding to.

Thus, even if there are three or more indoor units,
Similarly, by performing the switching control of the switching valve, the cooling and heating operation can be easily performed independently for each indoor unit. In addition, the refrigerant passes through the indoor unit for heating, passes through the outdoor heat exchanger by the bypass pipe, and is further guided through the expansion valve, so that the temperature of the refrigerant can be reduced in two stages. Therefore, the cooling capacity can be improved and the performance of the multi-type air conditioner can be improved as compared with the case where only the heat is passed through or the pressure is reduced only by the expansion valve.

Next, an air conditioner of another embodiment is shown in FIG.
Shown in That is, an electromagnetic valve is used instead of the three-way switching valve as the switching valve. At this time, since the solenoid valve is an on-off valve for opening and closing a pipeline, two three-way solenoid valves are required for one three-way switching valve. Other configurations are the same as the above embodiment.

In the case of only the cooling operation, the first solenoid valve 20b,
The second solenoid valve 21b, the third solenoid valves 22a and 22b, and the fourth solenoid valves 25a and 25b are closed. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 passes through the first solenoid valve 20a and the second solenoid valve 21a, is cooled by the outdoor heat exchanger 2 and becomes a liquid refrigerant, passes through the fourth solenoid valves 24a and 24b, The pressure is reduced by the expansion valves 3a and 3b corresponding to the operating indoor units A and B,
It is heated by the indoor heat exchanger 4 to become a low-pressure gas refrigerant, and cools the room. Then, the third solenoid valves 23a, 23
After b, the process returns to the compressor 1.

In the case of only the heating operation, the first solenoid valve 20a,
The second solenoid valve 21a, the third solenoid valves 23a and 23b, and the fourth solenoid valves 25a and 25b are closed. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 passes through the first solenoid valve 20b and the third solenoid valves 22a and 22b, and the indoor units A and B being operated.
And becomes a liquid refrigerant in the indoor heat exchanger 4 to heat the room.
The expansion valves 3a, 3b corresponding to the indoor units A, B
, Passes through the fourth solenoid valves 24a and 24b, becomes a low-pressure gas refrigerant in the outdoor heat exchanger 4, and becomes the second solenoid valve 21b
And returns to the compressor 1.

In the simultaneous cooling and heating operation, for example, when the indoor unit A performs the heating operation and the indoor unit B performs the cooling operation, the first solenoid valve 20
a, the second solenoid valve 21b, the third solenoid valves 22b and 23a, and the fourth solenoid valves 24a and 25b are closed. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 passes through the first solenoid valve 20b and the third solenoid valve 22a on the indoor unit A side, and passes through the indoor heat exchanger 4
And turns into a liquid refrigerant to heat the room where the indoor unit A is located. The expansion valve 3a, the fourth solenoid valve 25a, and the second
The liquid refrigerant is further cooled in the outdoor heat exchanger 2 via the electromagnetic valve 21a, passes through the fourth electromagnetic valve 24b on the indoor unit B side, is depressurized by the expansion valve 3b, and is depressurized by the indoor heat exchanger 4. It becomes a gas refrigerant to cool the room where the indoor unit B is located. Thereafter, the flow returns to the compressor 1 via the third solenoid valve 23b.

In another embodiment, as shown in FIG. 5, first to fourth four-way switching valves 30, 31, 32a, 32b, 33a, 33b are used as switching valves instead of three-way switching valves.
Is used. At this time, the pipe connected to one of the four ports of the four-way switching valve is closed as shown by a black circle in the figure, and is not connected anywhere. Other configurations are the same as the above embodiment.

Here, in the case of only the cooling operation, the first four-way switching valve 30 is a broken line, the second four-way switching valve 31 is a solid line, and the indoor unit A
The fourth four-way switching valve 32a on the indoor unit B side is a broken line, the third four-way switching valve 32b on the indoor unit B side is a solid line, and the fourth four-way switching valve 3 on the indoor unit A side is
3a is switched as indicated by a broken line, and the fourth four-way switching valve 33b on the indoor unit B side is switched as indicated by a solid line. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is supplied to the first four-way switching valve 3.
0, the refrigerant passes through the second four-way switching valve 31 and is cooled by the outdoor heat exchanger 2 to become a liquid refrigerant, passes through the fourth four-way switching valves 33a and 33b, and corresponds to the operating indoor units A and B.
The pressure is reduced at a and 3b and heated by the indoor heat exchanger 4 to become a low-pressure gas refrigerant to cool the room. Thereafter, the flow returns to the compressor 1 via the third four-way switching valves 32a and 32b.

In the case of only the heating operation, the first four-way switching valve 30
Is a solid line, the second four-way switching valve 31 is a broken line, and the third
The four-way switching valve 32a is shown by a solid line, the third four-way switching valve 32b on the indoor unit B side is shown by a broken line, the fourth four-way switching valve 33a on the indoor unit A side is shown by a broken line, and the fourth four-way switching valve 33b on the indoor unit B side is shown by a solid line. Are switched as follows. However, the fourth four-way switching valves 33a and 33b are switched as shown by the solid line. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 passes through the first four-way switching valve 30 and the third four-way switching valve 32
After passing through a and 32b, it becomes a liquid refrigerant in the indoor heat exchanger 4, and heats the room. Thereafter, the pressure is reduced by the expansion valves 3a, 3b, passes through the fourth four-way switching valves 33a, 33b, becomes a low-pressure gas refrigerant in the outdoor heat exchanger 2, and returns to the compressor 1 via the second four-way switching valve 31.

In the simultaneous cooling and heating operation, for example, when the indoor unit A performs the heating operation and the indoor unit B performs the cooling operation, each four-way switching valve is switched as shown by a solid line in the figure. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 passes through the first four-way switching valve 30, passes through the third four-way switching valve 32a on the indoor unit A side, becomes a liquid refrigerant in the indoor heat exchanger 4, and becomes an indoor unit. The room with A is heated. After the liquid refrigerant is further cooled in the outdoor heat exchanger 2 through the expansion valve 3a, the fourth four-way switching valve 33a, and the second four-way switching valve 31 in the fully opened state, the fourth four-way switching valve on the indoor unit B side After passing through 33b, the pressure is reduced by the expansion valve 3b and becomes a low-pressure gas refrigerant in the indoor heat exchanger 4 to cool the room where the indoor unit B is located. Thereafter, the flow returns to the compressor 1 via the third four-way switching valve 32b.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention. For example, in the above embodiment, the expansion valve, which is a flow control valve, fulfills the function of an on-off valve for opening and closing a pipeline in addition to the original function as a pressure reducing device. Therefore, as shown in FIG. 6, the two functions may be separated, and the first connection pipe 5 may be provided with the expansion valve 3 and the solenoid valves 35 a and 35 b as on / off valves. The expansion valve 3 has only a function as a decompressor, and is disposed in a pipe close to the outdoor heat exchanger 2 where the first connection pipe 5 is not branched, and the solenoid valves 35a and 35b are connected to the indoor units A and B, respectively. Place in the piping leading to. According to this, even if the number of indoor units increases, it is only necessary to add an inexpensive solenoid valve, so the more the indoor units are, the more useful.

[0034]

As is apparent from the above description, according to the present invention, by combining a flow control valve and a switching valve for one indoor unit and further providing a bypass pipe,
It is possible to switch the flow of the refrigerant between one outdoor unit and a plurality of indoor units according to a desired operation, so that not only the cooling operation and the heating operation but also the simultaneous cooling and heating operation can be performed. This makes it possible to easily perform the cooling and heating operation independently for each indoor unit, and to provide an air conditioner that can respond to the demands of various indoor environments.

Further, even when the number of indoor units is increased, it is only necessary to add a flow control valve, a switching valve, and a bypass pipe, so that the entire configuration is not complicated and the construction can be easily performed. Therefore, as the number of indoor units increases, the effect of cost reduction increases.

[Brief description of the drawings]

FIG. 1 is a refrigerant cycle diagram of a multi-type air conditioner according to an embodiment of the present invention.

FIG. 2 is a refrigerant cycle diagram of the air conditioner during the simultaneous cooling and heating operation.

FIG. 3 is a refrigerant cycle diagram of an air conditioner when an indoor unit is added.

FIG. 4 is a refrigerant cycle diagram of an air conditioner according to another embodiment using a solenoid valve.

FIG. 5 is a refrigerant cycle diagram of an air conditioner of another embodiment using a four-way switching valve.

FIG. 6 is a refrigerant cycle diagram of an air conditioner of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Outdoor heat exchanger 3a, 3b Expansion valve 4 Indoor heat exchanger 10 1st switching valve 11 2nd switching valve 12a, 12b 3rd switching valve 13a, 13b 4th switching valve 14 Bypass pipe A, B Indoor unit

Claims (5)

[Claims] An outdoor unit having a compressor, an outdoor heat exchanger, and a plurality of flow control valves, and a plurality of indoor units each having an indoor heat exchanger and arranged in parallel, are connected by a main pipe. A main pipe is provided with a bypass pipe that straddles the outdoor heat exchanger. One end of the bypass pipe is connected to an intermediate point between the outdoor heat exchanger and each indoor unit, and the other end is connected to the compressor and the outdoor heat exchanger. Connected to an intermediate point with the exchanger,
A switching valve is provided at each intermediate point, during cooling and heating simultaneous operation, sends the refrigerant discharged from the compressor to an indoor unit that performs heating, and after flowing the refrigerant to the outdoor heat exchanger by the bypass pipe to release heat, A multi-type air conditioner, wherein the air is sent to an indoor unit that performs cooling through the flow control valve. 2. An outdoor unit having a compressor, a plurality of switching valves, an outdoor heat exchanger and a plurality of flow control valves, and a plurality of indoor units each having an indoor heat exchanger and arranged in parallel, The outdoor heat exchanger and each indoor unit are connected through the flow control valve, and a pipe branched from a first intermediate point between the discharge side of the compressor and the outdoor heat exchanger is connected to each indoor unit. A bypass pipe is connected to an intermediate point between the compressor and the suction side, and branches from a second intermediate point between the discharge side of the compressor and the outdoor heat exchanger. A switching valve is provided at each of the intermediate points with the valves, and a switching valve is provided at each of the intermediate points. During the simultaneous cooling and heating operation, the refrigerant discharged from the compressor is sent to an indoor unit that performs heating, and the refrigerant is transmitted to the outdoor unit by the bypass pipe. After flowing through the heat exchanger and releasing heat, through the flow control valve A multi-type air conditioner characterized by being sent to an indoor unit for cooling. 3. The multi-type air conditioner according to claim 1, wherein the switching valve is a three-way switching valve. 4. The multi-type air conditioner according to claim 3, wherein two on-off valves are used instead of the three-way switching valve. 5. The multi-type air conditioner according to claim 3, wherein a four-way switching valve is used instead of the three-way switching valve, and three of the four ports are used.