JPH05172430A - Air conditioning apparatus - Google Patents

Abstract

PURPOSE:To provide an air conditioning apparatus in which a cooling capability is prevented from being decreased by a method wherein pipings for connecting a heat source machine to an indoor machine are changed over in response to a changing-over of condensation and evaporation of a heat exchanger at the heat source machine and a piping having a larger diameter is always applied at a low pressure side. CONSTITUTION:A heat source machine A and a plurality of indoor machines B, C and D are connected by the first and second connecting pipings 6 and 7 through a relay device E. This system is further provided with a six-way transfer valve 2 for use in connecting a discharging piping of a compressor 1 with either one piping or the second connecting piping 7 of a heat exchanger 3 at the heat source machine while being changed over, connecting the other piping of the heat exchanger 3 at the heat source machine to either the second connecting piping 7 or the inlet piping of an accumulator 4 and for connecting the first connecting piping 6 to either the inlet piping of the accumulator 4 or one piping of the heat exchanger 3 at the heat source machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room heat pump air conditioner in which a plurality of indoor units are connected to one heat source unit, and in particular, heating and cooling are selectively applied to each indoor unit, and The present invention relates to an air conditioner capable of simultaneously performing cooling in one indoor unit and heating in the other indoor unit.

[0002]

2. Description of the Related Art The prior art of the present invention will be described below. FIG. 7 is an overall configuration diagram centering on a refrigerant system of a conventional air conditioner capable of simultaneous cooling and heating operation disclosed in Japanese Patent Laid-Open No. 2-118372. 8 to 10 show operation states during cooling / heating operation in the air conditioner shown in FIG. 7, and FIG. 8 is an operation state diagram of only cooling or heating,
9 and 10 show the operation of the cooling and heating simultaneous operation,
FIG. 9 is an operation state diagram showing heating mainly (when the heating operation capacity is larger than the cooling operation capacity), and FIG. 10 is an operation operation state diagram showing cooling mainly (when the cooling operation capacity is larger than the heating operation capacity).

A is a heat source unit, and B, C, and D are indoor units connected in parallel with each other, which will be described later, and have the same structure. As will be described later, E is a repeater having a first branch part, a second flow rate control device, and a second branch part. Reference numeral 1 is a compressor, 2 is a four-way switching valve that switches the refrigerant flow direction of the heat source unit, 3 is a heat source unit side heat exchanger, 4 is an accumulator, which is connected to the above devices 1 to 3 and constitutes a heat source unit A. 5 is 3
Indoor heat exchanger of the table, 6 is the first connecting pipe connecting the four-way switching valve 2 of the heat source unit A and the relay E, and 6b, 6c, 6d are the indoor heat of the indoor units B, C, D, respectively. The exchanger 5 and the repeater E are connected to each other, and the indoor unit side first connection pipe corresponding to the first connection pipe 6 is connected to the heat source side heat exchanger 3 of the heat source unit A and the repeater E. The second connection pipes 7b, 7c, 7d connect the indoor heat exchanger 5 and the repeater E of the indoor units B, C, D respectively to the second indoor unit side corresponding to the second connection pipe 7.
Connecting pipe, 8 is the first connecting pipe 6b, 6 on the indoor unit side
c and 6d, a three-way switching valve 9 that is switchably connected to the first connection pipe 6 or the second connection pipe 7 side, and 9 are connected in close proximity to the indoor heat exchanger 5, and heat is generated during cooling. The first flow rate control device is controlled by the superheat amount on the outlet side of the exchanger 5 and the subcool amount during heating, and is connected to the second connection pipes 7b, 7c, 7d on the indoor unit side. Reference numeral 10 denotes a first branch portion including a first connection pipe 6b, 6c, 6d on the indoor unit side and a three-way switching valve 8 switchably connected to the first connection pipe 6 or the second connection pipe 7. , 11 is a second branch portion formed by the second connection pipes 7b, 7c, 7d on the indoor unit side, and 13 is a first branch portion 10 of the second connection pipe 7 and a second branch portion. 2 is a second flow rate control device that connects the branch portion 11 of FIG.

A conventional example of the present invention thus constructed will be described. First, the case of only the cooling operation will be described with reference to FIG. That is, as shown by the solid arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, is heat-exchanged in the heat source unit side heat exchanger 3, and is condensed and liquefied. 2 in order of the connection pipe 7 and the second flow control device 13, and further through the second branch portion 11 and the second connection pipes 7b, 7c, 7d on the indoor unit side, and the indoor units B,
It flows into C and D. Then, the refrigerant flowing into each of the indoor units B, C, D is decompressed to a low pressure by the first flow rate control device 9 and is heat-exchanged with the indoor air in the indoor heat exchanger 5 to be evaporated and gasified indoors. To cool down. The refrigerant in the gas state is used as the first connection pipes 6b, 6c on the indoor unit side,
6d, a three-way switching valve 8, a first branch portion 10, a first connecting pipe 6, a four-way switching valve 2 of the heat source device, an accumulator 4, and a circulation cycle that is sucked into the compressor 1 to form a cooling operation. To perform. At this time, the first port 8a of the three-way switching valve 8 is closed, and the second port 8b and the third port 8c are open.

Next, the case of only the heating operation will be described with reference to FIG. That is, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2 as shown by the dotted arrow in the figure, and passes through the first connecting pipe 6 and the first branch portions 10 and 3.
One-way switching valve 8, first connection pipes 6b, 6c, 6 on the indoor unit side
The air flows into the indoor units B, C, and D in the order of d, and exchanges heat with the indoor air to be condensed and liquefied to heat the room. And
The refrigerant in the liquid state passes through the first flow rate control device 9, passes through the second connection pipes 7b, 7c, 7d on the indoor unit side, and the second
Of the first flow rate control device 9 or the second flow rate control device 13 where the low pressure two-phase state is reached. Decompressed to. Then, the refrigerant decompressed to a low pressure,
The heat source unit side heat exchanger 3 of the heat source unit A via the second connection pipe 7.
The refrigerant that has flowed into the chamber and has exchanged heat and evaporated into a gas state passes through the four-way switching valve 2 of the heat source unit and the accumulator 4 and then passes through the compressor 1
It constitutes a circulation cycle that is sucked into and performs heating operation. At this time, the three-way switching valve 8 is opened and closed as in the case of only the cooling operation described above.

A case of mainly heating in the cooling / heating simultaneous operation will be described with reference to FIG. That is, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 is sent to the repeater E through the first connecting pipe 6 as shown by the dotted arrow in the figure, and then the first branching portion 10 and the three-way switching valve. 8, the first on the indoor unit side
Through the connecting pipes 6b and 6c in order to flow into the indoor units B and C to be heated, and the indoor side heat exchanger 5 exchanges heat with the indoor air to be condensed and liquefied to heat the room. Then, the condensed and liquefied refrigerant passes through the first flow rate control device 9 in a substantially fully opened state, is slightly decompressed, and flows into the second branch portion 11. Then, a part of this refrigerant passes through the first connection pipe 7d on the indoor unit side and enters the indoor unit D that is going to be cooled,
After entering the flow rate control device 9 and being decompressed, it enters the indoor heat exchanger 5 to exchange heat and evaporate into a gas state to cool the room, and the second connection pipe via the three-way switching valve 8. Inflow to 7. On the other hand, the other refrigerant flows into the second connection pipe 7 through the second branch portion 11 and the second flow rate control device 13, and merges with the refrigerant that has passed through the indoor unit D to be cooled, thereby forming a heat source unit. A
It flows into the heat source side heat exchanger 3 to exchange heat and evaporate into a gas state. Then, the refrigerant forms a circulation cycle in which it is sucked into the compressor 1 via the four-way switching valve 2 of the heat source device and the accumulator 4, and performs heating-main operation. At this time, the first port 8a of the three-way switching valve 8 connected to the indoor units B and C is closed, the second port 8b and the third port 8c are open, and the second port 8b of the indoor unit D is closed. , The first port 8a and the third port 8c are circuited.

A case of mainly cooling in the simultaneous heating and cooling operation will be described with reference to FIG. That is, as shown by the solid arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 exchanges an arbitrary amount with the heat-source-side heat exchanger 3 to become a gas-liquid two-phase high-temperature high-pressure state. It is sent to the repeater E through the connection pipe 7 of. Then, a part of this refrigerant is used for the first branch portion 10, the three-way switching valve 8, and the first connection pipe 6 on the indoor unit side.
In the order of d, the air flows into the indoor unit D to be heated, exchanges heat with the indoor air in the indoor heat exchanger 5 to be condensed and liquefied, and heats the room. Further, it flows into the second branch portion 11 through the first flow rate control device 9 which is in a substantially fully opened state. On the other hand, the remaining refrigerant passes through the second flow rate control device 13 and the second branch 1
1, and joins the refrigerant having passed through the indoor unit D to be heated. Then, the second branch portion 11, the second indoor unit side second
Through the connecting pipes 7b and 7c in this order and flow into the indoor units B and C. Then, the refrigerant that has flowed into each of the indoor units B and C is decompressed to a low pressure by the first flow rate control device 9 and flows into the indoor heat exchanger 5, where it is heat-exchanged with the indoor air to be evaporated and gasified. To cool down. Further, the refrigerant in the gas state is used as the first connection pipes 6b and 6c on the indoor unit side, the three-way switching valve 8, the first branch portion 10, the first connection pipe 6, and the heat source unit 4
A circulation cycle in which the air is taken into the compressor 1 via the one-way switching valve 2 and the accumulator 4 constitutes a cooling-main operation. At this time, the first ports 8a to 8c of the three-way switching valve 8 connected to the indoor units B, C, and D are opened and closed as in the heating-main operation.

[0008]

The conventional two-pipe type air conditioner capable of simultaneous cooling and heating operation is constructed as described above, and therefore, by switching the four-way switching valve, the first and second connecting pipes are connected. The flow of refrigerant in the repeater is reversed,
The operating state changed abruptly each time the direction switching valve was switched, and it took time to stabilize the system. Further, during heating-based operation, there is a problem that the pressure loss of the second connecting pipe is large and the capacity of the cooling indoor unit is insufficient.

The present invention has been made to solve the above problems, and the refrigerant flow in the first and second connecting pipes and the repeater even when the four-way switching valve is switched. The purpose of the present invention is to provide an air conditioner that allows simultaneous operation of cooling and heating with the system in one direction. Another object of the present invention is to always use the first connection pipe, which is thicker than the second connection pipe, on the low-pressure side to reduce the low-pressure pressure loss and suppress the deterioration of the capacity of the cooling indoor unit.

Further, it is an object of the present invention to make the flow of the refrigerant in the heat source side heat exchanger unidirectional.

[0011]

SUMMARY OF THE INVENTION An air conditioner according to the present invention includes a heat source unit consisting of a compressor, a heat source unit side heat exchanger, and an accumulator, an indoor side heat exchanger, and a first flow rate control. A plurality of indoor units made up of devices are connected via first and second connecting pipes, and one of the indoor heat exchangers of the plurality of indoor units is connected to the first connecting pipe or the second connecting pipe. A first branch part provided with a valve device switchably connected to the connection pipe, and the other of the indoor heat exchangers of the plurality of indoor units via the first flow control device, and A second branch portion connected to the second connection pipe via the second flow rate control device is connected via the second flow rate control device, and the first branch portion and the second Branching unit, a repeater incorporating the second flow rate control device, the heat source unit and the plurality of indoor units, In the case of being interposed therebetween, the pipe diameter of the first connecting pipe is made larger than the pipe diameter of the second connecting pipe, and the discharge pipe of the compressor is connected to one pipe of the heat source side heat exchanger. , Switchably connected to the second connection pipe, and switchably connect the other pipe of the heat source side heat exchanger to the second connection pipe and the inlet pipe of the accumulator, and , A six-way switching valve that connects the first connection pipe to the inlet pipe of the accumulator and one pipe of the heat source side heat exchanger so as to be switchable.

[0012]

In the present invention, when the heat source side heat exchanger is used as a condenser, the six-way switching valve connects the discharge pipe of the compressor and one pipe of the heat source side heat exchanger, and The other pipe of the heat source side heat exchanger is connected to the second connection pipe, and the inlet pipe of the accumulator is connected to the first connection pipe.

When the heat source side heat exchanger is used as an evaporator, the six-way switching valve connects the discharge pipe of the compressor and the second connecting pipe, and the first connecting pipe and the heat source unit. One pipe of the side heat exchanger is connected, and the other pipe of the heat source side heat exchanger is connected to the inlet pipe of the accumulator.

[0014]

【Example】

Example 1. Examples of the present invention will be described below.
1 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a first embodiment of the present invention. 2 to 5 show operating states during cooling and heating operation in the air conditioner shown in FIG. 1, FIG. 2 is an operating state diagram only for cooling, and FIG. 3 is an operating state diagram only for heating. 4 and 5 show the operation of the cooling and heating simultaneous operation. FIG. 4 shows heating mainly (when the heating operation capacity is larger than the cooling operation capacity), and FIG. 5 shows cooling mainly (the cooling operation capacity is larger than the heating operation capacity). If)
FIG. 6 is a driving operation state diagram showing In this example,
A case where three indoor units are connected to one heat source unit will be described, but the same applies when two or more indoor units are connected.
In FIG. 1, A is a heat source unit, and B, C, and D are indoor units connected in parallel with each other as described later, and have the same configuration. As will be described later, E is a first branch part, a second flow rate control device, a second branch part, a gas-liquid separation device, a heat exchange part, a third flow rate control device, and a fourth flow rate control device. It is a built-in repeater. Reference numeral 1 is a compressor, and 2 is a 6-way switching valve that switches the refrigerant flow direction of the heat source device, and has a structure in which two flow path switching portions of a conventional 4-way switching valve are provided in series. Reference numeral 3 is a heat source unit side heat exchanger, and 4 is an accumulator, which is connected to the above-mentioned equipment, and the heat source unit A is constituted by these. Reference numeral 5 is an indoor heat exchanger provided in each of the three indoor units B, C, and D, and 6 is a thick first first connecting the four-way switching valve 2 of the heat source device A and the relay E.
Connection pipes, 6b, 6c, 6d are indoor units B, respectively.
The indoor heat exchanger 5 of C and D is connected to the relay E, and the indoor unit side connecting pipe corresponding to the first connecting pipe 6 is denoted by 7 and the heat source unit side heat exchanger 3 of the heat source unit A is connected to the relay unit 7. Connect E, above first
The second connecting pipe 6 has a thinner second connecting pipe, 7b, 7c,
7d is a second connection pipe on the indoor unit side that connects the indoor heat exchanger 5 and the repeater E of the indoor units B, C, and D, and corresponds to the second connection pipe 7, and 8 is an indoor unit side. First connection pipe 6
b, 6c, 6d and the first connection pipes 6b, 6c, 6d and the first connection pipes which are switchably connected to the first connection pipe 6 or the second connection pipe 7 side and which are on the indoor unit side. It is possible to close the circulation with both 6 and the second connecting pipe 7.
The one-way switching valve, 9 is connected close to the indoor heat exchanger 5,
The first flow control device is controlled by the superheat amount on the outlet side of the indoor heat exchanger 5 during cooling and by the subcool amount during heating, and the second connection pipes 7b, 7c, 7 on the indoor unit side.
connected to d. 10 is the first connection pipe 6 on the indoor unit side
b, 6c, 6d, and a first branch portion composed of a three-way switching valve 8 switchably connected to the first connection pipe 6 or the second connection pipe 7, 11 is a second connection on the indoor unit side Piping 7b, 7
c, 7d, a second branch portion consisting of the second connecting pipe 7, 1
2 is a gas-liquid separation device provided in the middle of the second connecting pipe 7, the gas layer portion of which is connected to the first port 8a of the three-way switching valve 8, and the liquid layer portion of which is the second branch portion 11 It is connected to the.
Reference numeral 13 denotes a second flow rate control device (here, an electric expansion valve) which is connected between the gas-liquid separation device 12 and the second branch portion 11 and which can be opened and closed, and 14 denotes the second branch portion 11 and the above-mentioned first 1 is a bypass pipe connecting to the connection pipe 6; 15 is a bypass pipe 14
A third flow control device (here, an electric expansion valve) 16a provided in the middle of the flow path, a 16a is provided downstream of the third flow control device 15 provided in the middle of the bypass pipe 14, and has a second branch portion. The second connection pipe 7b on the indoor unit side in FIG.
The second heat exchange section 16b, 16c, 16d for exchanging heat with the meeting section of 7c, 7d, and the third flow control device 1 provided in the middle of the bypass pipe 14 are provided.
5, a third heat exchanging unit 19 for exchanging heat with the connecting pipes 7b, 7c, 7d on the indoor unit side of the second branching unit 11, and the bypass pipe 14
Downstream of the third flow rate control device 15 of
Is provided downstream of the heat exchange section 16a of the
And a second flow control unit 13 for exchanging heat between a pipe connecting the second flow rate control device 13 and a second branch unit 11.
Is a fourth flow rate control device (here, an electric expansion valve) that is openable and closable and is connected between the first connection pipe 6 and the first connection pipe 6.

An embodiment of the present invention thus constructed will be described. First, the case of only the cooling operation will be described with reference to FIG. That is, as shown by the solid arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the 6-way switching valve 2 and is heat-exchanged with air in the heat source side heat exchanger 3 to be condensed and liquefied. , The 6-way switching valve 2, the second connection pipe 7, the gas-liquid separator 12, and the second flow rate control device 13 in this order, the second branch portion 11, the second connection pipe 7b on the indoor unit side, It passes through 7c and 7d and flows into each indoor unit B, C and D. The refrigerant flowing into each indoor unit B, C, D is
The pressure is reduced to a low pressure by the first flow rate control device 9 controlled by the superheat amount at the outlet of each indoor heat exchanger 5, and the indoor heat exchanger 5 exchanges heat with the indoor air to evaporate and gasify. To cool down. The refrigerant in the gas state is used for the first connection pipes 6b, 6c, 6d on the indoor unit side,
Three-way switching valve 8, first branch portion 10, first connecting pipe 6,
A circulation cycle in which the compressor 1 is sucked through the 6-way switching valve 2 and the accumulator 4 constitutes a cooling operation. At this time, the first port 8a of the three-way switching valve 8 is closed, and the second port 8b and the third port 8c are open. Further, during this cycle, a part of the refrigerant that has passed through the second flow rate control device 13 enters the bypass pipe 14 and is depressurized to a low pressure by the third flow rate control device 15 so that the third heat exchange parts 16b, 16c. , 16d
The second connection pipe 7 on the indoor unit side of the second branch portion 11
After exchanging heat with b, 7c and 7d, a branch base pipe section to the second connection pipes 7b, 7c and 7d on the indoor unit side of the second branch section 11 in the second heat exchange section 16a. Exchange heat with. Furthermore, in the first heat exchange section 19, the second flow rate control device 13
The refrigerant that has undergone heat exchange with the refrigerant flowing into the
It enters the first connection pipe 6 and is sucked into the compressor 1 via the 6-way switching valve 2 of the heat source device and the accumulator 4. On the other hand, the first, second, and third heat exchange parts 19, 16a, 16b, 16
The refrigerant in the second branch portion 11 that has been heat-exchanged and cooled in c and 16d and is sufficiently subcooled flows into the indoor units B, C and D that are about to be cooled.

Next, the case of only the heating operation will be described with reference to FIG. That is, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the six-way switching valve 2, the second connecting pipe 7, the gas-liquid separation device 12, and the first Branch portion 10, 3-way switching valve 8, first indoor unit side
The connection pipes 6b, 6c, 6d of the
It flows into C and D, exchanges heat with indoor air to condense and liquefy, and heats the room. Then, the refrigerant in the liquid state is controlled by the subcool amount at the outlet of each indoor heat exchanger 5 and passes through the first flow rate control device 9 in a substantially fully opened state, and the second connection pipe 7b on the indoor unit side. , 7c, 7d to second branch 1
1 and merges, and further passes through the fourth flow rate control device 17. Here, the first flow control device 9 or the third and fourth flow control devices
Either one of the flow rate control devices 15 and 17 is used to reduce the pressure to a low-pressure two-phase state. Then, the refrigerant decompressed to a low pressure flows into the 6-way switching valve 2 and the heat source side heat exchanger 3 through the first connecting pipe 6, where it exchanges heat with air and evaporates into a gas state. Is a 6-way switching valve 2 and accumulator 4
After that, a circulation cycle of being sucked into the compressor 1 is formed, and heating operation is performed. At this time, the three-way switching valve 8 has the second port 8b.
Is closed, and the first port 8a and the third port 8c are open.

A case of mainly heating in the simultaneous heating and cooling operation will be described with reference to FIG. That is, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 is sent to the relay device E through the six-way switching valve 2 and the second connecting pipe 7 as shown by the solid line arrow in the figure, and the gas-liquid separation device 12 Through the first branch portion 10, the three-way switching valve 8, and the first connection pipes 6b, 6c on the indoor unit side in this order, and each indoor unit B to be heated,
It flows into C, heat-exchanges with the indoor air in the indoor heat exchanger 5, is condensed and liquefied, and heats the room. Then, the condensed and liquefied refrigerant is controlled by the subcool amounts at the outlets of the indoor heat exchangers B and C, passes through the first flow rate control device 9 in a substantially fully opened state, is slightly decompressed, and flows into the second branch portion 11. To do. And a part of this refrigerant is the second connection pipe 7d on the indoor unit side.
After passing through the first flow rate control device 9, the pressure is reduced, and the air enters the indoor unit D to be cooled and heat-exchanges with the indoor air to be vaporized. Then, this gas refrigerant is controlled by the superheat amount at the outlet of the indoor heat exchanger D via the first flow rate control device 9, cools the room, and passes through the three-way switching valve 8 to the first
Flowing into the connecting pipe 6. On the other hand, the other refrigerant flows through the fourth flow rate control device 17, merges with the refrigerant that has passed through the indoor unit D to be cooled, and passes through the thick first connection pipe 6 to the 6-way switching valve 2 and the heat source unit side. It flows into the heat exchanger 3 where it exchanges heat with air and evaporates to become a gas state. And the refrigerant is 6
A circulation cycle in which the compressor 1 is sucked through the one-way switching valve 2 and the accumulator 4 constitutes a heating-main operation. At this time, the evaporation pressure of the indoor side heat exchanger 5 of the indoor unit D to be cooled and the pressure difference of the heat source unit side heat exchanger 3 are reduced because of switching to the thick first connecting pipe 6. At this time, the second port 8b of the three-way switching valve 8 connected to the indoor units B and C is closed,
The first port 8a and the third port 8c are opened, and the indoor unit D
The first port 8a is closed, and the second port 8b and the third port 8c are circuited. In addition, during this cycle, part of the liquid refrigerant is the second connection pipes 7b, 7 on the indoor unit side of the second branch portion 11
It enters into the bypass pipe 14 from the confluence part of c and is decompressed to a low pressure by the third flow rate control device 15, and the third heat exchange part 16
b, 16c and 16d, heat is exchanged with the second connection pipes 7b, 7c and 7d on the indoor unit side of the second branch portion 11, and the second branch portion is further connected to the second heat exchange portion 16a. The refrigerant that has performed heat exchange with the confluent portions of the second connection pipes 7b and 7c on the indoor unit side of 11 enters the first connection pipe 6 and enters the 6-way switching valve 2 and the accumulator 4 of the heat source device. After that, it is sucked into the compressor 1. On the other hand, the second and third heat exchange parts 16a, 16b,
The refrigerant in the second branch portion 11 that has been heat-exchanged and cooled in 16c and 16d and is sufficiently subcooled flows into the indoor unit D that is about to be cooled.

A case of mainly cooling in the simultaneous heating and cooling operation will be described with reference to FIG. That is, the refrigerant gas discharged from the compressor 1 as shown by the solid line arrow in FIG.
It passes through the one-way switching valve 2 and flows into the heat exchanger 3 on the heat source side, where it exchanges heat with the air and becomes a two-phase high-temperature high-pressure state. After that, the gas-liquid two-phase high-temperature and high-pressure refrigerant is transferred to the six-way switching valve 2, the second
It is sent to the gas-liquid separation device 12 of the repeater E via the connection pipe 7 of. Then, here, it is separated into a gaseous refrigerant and a liquid refrigerant, and the separated gaseous refrigerant is passed through the first branch portion 10, the three-way switching valve 8, and the first connection pipe 6d on the indoor unit side in this order to heat the refrigerant. The indoor side heat exchanger 5 exchanges heat with the indoor air to condense and liquefy and heat the room. Further, it is controlled by the amount of subcool at the outlet of the indoor heat exchanger 5 and slightly depressurized through the first flow rate control device 9 in a substantially fully opened state, and then flows into the second branch portion 11. On the other hand, the remaining liquid refrigerant passes through the second flow rate control device 13 and the second branch portion 1
1, and joins the refrigerant having passed through the indoor unit D to be heated. Then, the second branch portion 11, the second indoor unit side second
Through the connecting pipes 7b and 7c in this order and flow into the indoor units B and C. Then, the refrigerant flowing into each indoor unit B, C is decompressed to a low pressure by the first flow rate control device 9 controlled by the superheat amount at the outlets of the indoor heat exchangers B, C, and exchanges heat with the indoor air. It is vaporized and gasified to cool the room. Further, the refrigerant in the gas state passes through the first connection pipes 6b and 6c on the indoor unit side, the three-way switching valve 8 and the first branch portion 10, and passes through the first connection pipes 6 and 6-way switching valve. 2. A circulation cycle in which the air is sucked into the compressor 1 via the accumulator 4 is configured to perform the cooling-main operation. At this time, the first port 8a of the three-way switching valve 8 connected to the indoor units B and C is closed,
The second port 8b and the third port 8c are opened, and the indoor unit D
The second port 8b is closed, and the first port 8a and the third port 8c are open. In addition, during this cycle, a part of the liquid refrigerant flows into the second connecting pipes 7b, 7 on the indoor unit side of the second branch portion 11.
It enters into the bypass pipe 14 from the meeting portion of c and 7d, is depressurized to a low pressure by the third flow rate control device 15, and is connected to each indoor unit side of the second branch portion 11 by the third heat exchange portions 16b, 16c and 16d. Heat is exchanged with the second connection pipes 7b, 7c, 7d, and the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch portion 11 are further exchanged by the second heat exchange portion 16a. The refrigerant that has undergone heat exchange with the first heat exchange section 19 and the refrigerant flowing into the second flow rate control device 13 and has evaporated is the first connection pipes 6, 6 It is sucked into the compressor 1 through the switching valve 2 and the accumulator 4. On the other hand, the refrigerant in the second branch portion 11 which is heat-exchanged and cooled in the first, second, and third heat exchange portions 19, 16a, 16b, and 16c and is sufficiently subcooled is about to be cooled by the indoor unit B. , C.

Example 2. In the above embodiment, the three-way switching valve 8 is provided and the first connection pipes 6b, 6c, 6 on the indoor unit side are provided.
d and the first connection pipe 6 or the second connection pipe 7 are switchably connected to each other. However, as shown in FIG. 6, two solenoid valves 30, 31 and other on-off valves are provided, as described above. Even if it is switchably connected, the same operational effect can be obtained.

[0020]

Since the present invention is constructed as described above, it has the following effects.

By switching the six-way switching valve, at the same time as switching between condensation and evaporation of the heat source side heat exchanger,
The second connection pipe can also be switched, and can be used at a low pressure all the time with the first connection pipe having a larger diameter than the second connection pipe, reducing the pressure loss on the low pressure side and cooling the indoor heat exchanger. It is possible to suppress a decrease in ability.

Since the direction of the flow of the refrigerant in the first and second connecting pipes, the repeater E, and the indoor units B, C, and D does not change with respect to the switching of the 6-way switching valve, the cooling system is mainly used. It is possible to suppress a transient decrease in capacity of the indoor unit when switching between the operating state of the operation and the heating-based operation.

By using the 6-way switching valve, switching of condensation / evaporation of the heat source side heat exchanger and connection switching of the first and second connecting pipes can be achieved by one functional component.

By using the 6-way switching valve, the flow direction of the refrigerant in the heat exchanger on the heat source side does not change due to the switching of condensation / evaporation on the heat exchanger on the heat source side. When used as a refrigerant heat exchanger and a heat source unit side heat exchanger, the flow of water and the refrigerant are always opposed to each other, and heat exchange efficiency can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an operation state of only the cooling of the air conditioner according to the first embodiment of the present invention.

[Fig. 3] Fig. 3 is a diagram showing the operation state of only the heating of the air-conditioning apparatus according to Embodiment 1 of the present invention.

[Fig. 4] Fig. 4 is a diagram showing the operation state of the heating main body of the air-conditioning apparatus according to Embodiment 1 of the present invention.

[Fig. 5] Fig. 5 is a diagram showing the operation state mainly of cooling of the air-conditioning apparatus according to Embodiment 1 of the present invention.

FIG. 6 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a second embodiment of the present invention.

FIG. 7 is an overall configuration diagram centering on a refrigerant system of a conventional air conditioner.

8 is a diagram showing an operation state of only the cooling or the heating of the air conditioner shown in FIG.

[Fig. 9] Fig. 9 is a diagram showing the operation state of the heating main body in the air-conditioning apparatus shown in Fig. 7.

[Fig. 10] Fig. 10 is a diagram showing the operation state of mainly the cooling in the air-conditioning apparatus shown in Fig. 7.

[Explanation of symbols]

 1 Compressor 2 6-way switching valve 3 Heat source machine side heat exchanger 4 Accumulator 5 Indoor side heat exchanger 6 1st connection piping 7 2nd connection piping 9 1st flow control device 10 1st branch part 11 1st Branch portion 2 13 Second flow rate control device 15 Third flow rate control device A Heat source unit B, C, D Indoor unit E Repeater

Claims (1)

[Claims] 1. A heat source unit comprising a compressor, a heat source unit side heat exchanger, and an accumulator, and a plurality of indoor units comprising an indoor side heat exchanger and a first flow rate control device. ,
The indoor heat exchangers of the plurality of indoor units are connected to each other via a second connection pipe, and one of the indoor heat exchangers is connected to the first connection pipe or the second connection pipe.
Connected to the other one of the indoor side heat exchangers of the plurality of indoor units via the first flow rate control device, and A second branch portion connected to the second connection pipe via the second flow rate control device is connected via the second flow rate control device, and the first branch portion and the second And a relay unit having the second flow rate control device built-in between the heat source unit and the plurality of indoor units.
The pipe diameter of the first connecting pipe is made larger than the pipe diameter of the second connecting pipe, and the discharge pipe of the compressor is one pipe of the heat source side heat exchanger, and the second connecting pipe. And the other pipe of the heat-source-unit-side heat exchanger are connectable to the second connection pipe and the inlet pipe of the accumulator, and the first connection pipe. Is provided with a 6-way switching valve that is connected to the inlet pipe of the accumulator and one pipe of the heat source side heat exchanger.