JPH0942804A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To take out a predetermined cooling capability rapidly by a method wherein a control means controls various kinds of flow rate control devices or electromagnetic opening or closing valves in such a way that an inside part of a second control piping or an inside part of a gas-liquid separator is replaced with at least gas-liquid two phase refrigerant when an operation is changed over from a heating mode operation to a cooling mode operation. SOLUTION: An operating volume for each of indoor devices B, C, D is detected by an indoor device operating volume sensing means 50 and if a cooling operation volume is higher than a heating operation volume, an operation is changed over to a full cooling operation. A fourth electromagnetic opening or closing valve 48 in a bypassing circuit 49 is opened, high pressure gas refrigerant within a second connecting pipe 7 and a gas-liquid separator device 12 is transferred to a first connecting pipe 6, it is heat exchanged with air by a heat exchanger 3 at a heat source machine and then condensed high pressure two-phase refrigerant is flowed into the second connecting pipe 7 and the gas-liquid separator device 12. Accordingly, the liquid refrigerant separated by the gas-liquid separator device 12 can be flowed into an indoor side heat exchanger 5 of an indoor device to be cooled through a first flow rate control device 9, resulting in that a predetermined cooling capability can be rapidly taken out.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art The prior art of this type of air conditioner will be described below. FIG. 9 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a conventional technique of the present invention.
10 to 12 show operating states during cooling / heating operation in the prior art of FIG. 9, FIG. 10 is an operation state diagram of only cooling or heating, and FIGS. 11 and 12 are operations of simultaneous cooling / heating operation. FIG. 11 is an operation state diagram showing a cooling main body (when the cooling operation capacity is larger than the heating operation capacity) and FIG. 12 is a heating main body (when the heating operation capacity is larger than the cooling operation capacity). In this prior art, 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. 9, A is a heat source unit, and B, C and D are indoor units connected in parallel with each other as will be described later, and have the same structure. As will be described later, E is a first branch unit 10, a second flow rate control device 13, and a second branch unit 1.
1, gas-liquid separator 12, second heat exchange section 16a, third heat exchange sections 16b, 16c, 16d, first heat exchange section 1
9, third flow controller 15, fourth flow controller 17
It is a repeater with a built-in. Further, 1 is a compressor, 2 is a four-way switching valve that switches the flow direction of the refrigerant from the compressor 1, 3 is a heat source side heat exchanger, 4 is an accumulator, and is connected to the compressor 1 via the four-way switching valve 2. ing. The heat source machine A is constructed from these. 5 is three indoor units B,
Indoor heat exchangers 6 respectively provided in C and D, and a thick first connecting pipe 6 for connecting the four-way switching valve 2 of the heat source unit A and the relay unit E via a second check valve 33 described later. , 6b, 6
Reference numerals c and 6d respectively connect the indoor heat exchangers 5 of the indoor units B, C and D and the relay unit E, and the indoor unit side first connection pipes corresponding to the first connection pipes 6, and 7 is a heat source. The heat source unit side heat exchanger 3 of the machine A and the relay unit E are connected via a first check valve 32, which will be described later, and are second connection pipes thinner than the first connection pipe 6.

Reference numerals 7b, 7c and 7d respectively connect the indoor heat exchangers 5 of the indoor units B, C and D and the relay unit E via the first flow rate control device 9, and the second connecting pipes. 7 is a second connection pipe on the indoor unit side corresponding to 7. Reference numeral 8a denotes the first connection pipes 6b, 6c, 6d on the indoor unit side and the first connection pipe 6
Is a first solenoid on-off valve for opening and closing the circuit with, and 8b is the first connection pipes 6b, 6c, 6d on the indoor unit side and the second connection pipe 7
Is a second electromagnetic on-off valve for opening and closing the circuit, and 8c is a third electromagnetic on-off valve connected in parallel with the first electromagnetic on-off valve 8a and having an opening diameter smaller than that of the first electromagnetic on-off valve 8a. 9 is connected to each of the indoor heat exchangers 5 in close proximity to each other, and during cooling, due to the superheat amount on the outlet side of the indoor heat exchanger 5,
At the time of heating, the first flow rate control device is controlled by the subcool amount, and is connected to the second connection pipes 7b, 7c, 7d on the indoor unit side. 10 is the above-mentioned first solenoid on-off valve 8a
And a second electromagnetic opening / closing valve 8b and a third electromagnetic opening / closing valve 8c. Reference numeral 11 denotes a second branch portion including the second connection pipes 7b, 7c, 7d on the indoor unit side and the second connection pipe 7. Reference numeral 12 is a gas-liquid separator provided in the middle of the second connecting pipe 7, the gas phase portion of which is connected to the first electromagnetic on-off valve 8a of the first branch portion 10 and the liquid phase portion of which is the second Is connected to the branch part 11. Reference numeral 13 denotes a second flow rate control device (here, an electric expansion valve) that is provided between the gas-liquid separation device 12 and the second branch portion 11 and can be opened and closed.

Reference numeral 14 is a first bypass pipe connecting the second branch portion 11 and the first connection pipe 6, and 15 is a third flow rate control device (here, a third flow control device) provided in the middle of the first bypass pipe 14. (Electrical expansion valve), 16a is the first bypass pipe 14
It is provided downstream of the third flow rate control device 15 on the way and
Second connection pipe 7 on each indoor unit side in branch portion 11 of
It is a second heat exchanging part for exchanging heat with the meeting parts of b, 7c and 7d. 16b, 16c, 16d are respectively provided on the downstream side of the third flow rate control device 15 provided in the middle of the first bypass pipe 14, and the second branch portion 11 is provided.
Second connection pipes 7b, 7c, 7d on the side of each indoor unit in
Is a third heat exchanging section for exchanging heat with each other.
19 is the third flow control device 1 of the first bypass pipe 14.
5, which is provided downstream of the second heat exchange unit 16a and performs heat exchange between the pipe connecting the gas-liquid separation device 12 and the second flow rate control device 13; 17
Is an openable and closable fourth flow rate control device (here, an electrical expansion valve) provided in the middle of the second bypass pipe 14a connecting the second branch portion 11 and the first connection pipe 6.

On the other hand, reference numeral 32 is a first check valve provided between the heat source unit side heat exchanger 3 and the second connecting pipe 7, which connects the heat source unit side heat exchanger 3 to the second connecting pipe. Allow the refrigerant flow only to 7. Reference numeral 33 is a second check valve provided between the four-way switching valve 2 of the heat source unit A and the first connecting pipe 6, and is a first check valve.
From the connection pipe 6 to the four-way switching valve 2 only. Reference numeral 34 denotes the four-way switching valve 2 of the heat source unit A and the second connection pipe 7
Is a third check valve provided between the four-way switching valve 2 and
To the second connection pipe 7 only. 35
Is a fourth check valve provided between the heat source device side heat exchanger 3 and the first connection pipe 6, and the refrigerant flows only from the first connection pipe 6 to the heat source device side heat exchanger 3. Tolerate. The above-mentioned first, second, third, and fourth check valves 32, 33, 34, 3
The flow path switching device 40 is composed of the combination structure of No. 5.
Further, 49 is a bypass circuit that connects the first connection pipe 6 and the second connection pipe 7, and 48 is a fourth electromagnetic circuit that is provided in the middle of the bypass circuit 49 and that controls the opening and closing of the bypass circuit 49. It is an on-off valve.

Reference numeral 25 is a first pressure detecting means provided between the first branch portion 10 and the second flow rate control device 13, and 26
Is a second pressure detecting means provided between the second flow rate control device 13 and the fourth flow rate control device 17.

Next, the operation will be described. First, FIG.
The case of "only the cooling operation" will be described using. As indicated by the solid line 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 with air in the heat-source-unit-side heat exchanger 3, and is condensed. 1, the check valve 32, the second connecting pipe 7, the gas-liquid separating device 12, and the second flow rate controlling device 13 in this order, the second branch portion 11, the second connecting 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 decompressed 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 It heats and exchanges heat with the room air, is gasified, and cools the room.

The refrigerant in the gas state is used for the first connection pipes 6b, 6c, 6d on the indoor unit side and the first solenoid on-off valve 8.
a and the third electromagnetic opening / closing valve 8c, the first branch portion 10, the first connecting pipe 6, the second check valve 33, the four-way switching valve 2 of the heat source device A, and the accumulator 4 to suck in the compressor 1. The cooling cycle is configured and the cooling operation is performed. At this time, the first
The electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c are opened, and the second electromagnetic control valve 8b is closed. At this time, the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, so that the refrigerant inevitably flows through the first check valve 32 and the second check valve 33. . Also, during this cycle, the second
Part of the refrigerant that has passed through the flow rate control device 13 enters the first bypass pipe 14 and is depressurized to a low pressure by the third flow rate control device 15, and then the second branch is performed by the third heat exchange units 16b, 16c, 16d. The second connection pipes 7b, 7 on the indoor unit side of the section 11
c, 7d, and the second connection pipes 7b, 7c on the indoor unit side of the second branch portion 11 in the second heat exchange portion 16a.
The first heat exchange section 19 and the second section of the 7d
The heat exchange with the refrigerant flowing into the flow rate control device 13 is performed and the heat is evaporated. The refrigerant thus evaporated enters the first connecting pipe 6 and the second check valve 33, and is sucked into the compressor 1 via the four-way switching valve 2 of the heat source unit A and the accumulator 4.

On the other hand, the first, second and third heat exchange parts 19,
16a, 16b, 16c, 16d exchange heat and are cooled,
The refrigerant in the second branch portion 11 that is sufficiently subcooled flows into the indoor units B, C, and D that are about to be cooled.

Next, the case of "only heating operation" will be described with reference to FIG. As indicated by the dashed arrow in the figure,
The high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, the third check valve 34, the second connecting pipe 7, the gas-liquid separation device 12, and the first branch portion 10, The second solenoid on-off valve 8b, the first connection pipes 6b, 6c, 6 on the indoor unit side
After passing through d in order, it flows into each of the indoor units B, C, D, exchanges heat with the indoor air to be condensed and liquefied, and heats the room.

The refrigerant in this 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 on the indoor unit side. From the pipes 7b, 7c and 7d, they flow into the second branch portion 11 and merge, and further pass through the fourth flow rate control device 17. Here, the refrigerant is decompressed by the first flow control device 9 or the third and fourth flow control devices 15 and 17 to a low-pressure gas-liquid two-phase state. The refrigerant reduced to a low pressure is the first connection pipe 6
Through the fourth check valve 35 of the heat source unit A and the heat exchanger 3 on the heat source unit side, and exchanges heat with air to evaporate and become a gas state,
A circulation cycle in which the compressor 1 is sucked through the four-way switching valve 2 of the heat source unit A and the accumulator 4 constitutes a heating operation. At this time, the first electromagnetic opening / closing valve 8a and the third electromagnetic opening / closing valve 8c are closed, and the second electromagnetic opening / closing valve 8b is opened. At this time, the refrigerant has a high pressure in the first connecting pipe 6 and a low pressure in the second connecting pipe 7, so that the refrigerant inevitably flows through the third check valve 34 and the fourth check valve 35. .

Next, the case of "mainly cooling in simultaneous cooling and heating operation" will be described with reference to FIG. As shown by the solid arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 flows into the heat source unit side heat exchanger 3 through the four-way switching valve 2 and exchanges heat with air to form a gas-liquid two-phase. It becomes a high temperature and high pressure state. After that, the two-phase high-temperature high-pressure refrigerant is sent to the gas-liquid separation device 12 of the relay machine E through the first check valve 32 and the second connection pipe 7. Here, the gaseous refrigerant is separated into a gaseous refrigerant and a liquid refrigerant, and the separated gaseous refrigerant sequentially passes through the first branch portion 10, the second electromagnetic opening / closing valve 8b, and the first connection pipe 6d on the indoor unit side, It flows into the indoor unit D to be heated, heat-exchanges with the indoor air in the indoor heat exchanger 5 to be condensed and liquefied, and heats the room. Further, it is controlled by the amount of subcool at the outlet of the indoor heat exchanger 5, passes through the first flow rate control device 9 in a substantially fully opened state, and is slightly decompressed to the second branch portion 1.
Flow into 1.

On the other hand, the remaining liquid refrigerant passes through the second flow rate control device 13 controlled by the pressure detected by the first pressure detecting means 25 and the pressure detected by the second pressure detecting means 26,
The indoor unit D that flows into the second branch portion 11 and tries to heat
And then merge with the refrigerant. And the combined refrigerant,
2nd branch part 11, 2nd connection piping 7b and 7 by the side of an indoor unit
It flows into each indoor unit B and C in order of c. The refrigerant flowing into each indoor unit B, C is depressurized to a low pressure by the first flow rate control device 9 controlled by the superheat amount at the outlet of the indoor unit heat exchanger 5, and then the indoor heat exchanger 5
Flows into the room, heat exchanges with the room air, evaporates and is gasified, and cools the room. Further, the refrigerant in the gas state passes through the first connection pipes 6b and 6c on the indoor unit side, the first electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c, the first branch portion 10, 1, the connection pipe 6, the second check valve 33, the heat source device A
The four-way switching valve 2 and the accumulator 4 form a circulation cycle that is sucked into the compressor 1 to perform the cooling main operation.
At this time, the first electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c connected to the indoor units B and C are open, and the second electromagnetic on-off valve 8b is closed, so that the indoor unit D is The first electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c that are connected are closed, and the second electromagnetic on-off valve 8b is opened. At this time, the refrigerant has a low pressure in the first connecting pipe 6 and a high pressure in the second connecting pipe 7, so that the first check valve 32 and the second check valve 33 are inevitable.
Distribute.

During this cycle, part of the liquid refrigerant is the second connecting pipes 7b, 7c on the indoor unit side of the second branch portion 11,
Enter the first bypass pipe 14 from the meeting point of 7d,
The pressure is reduced to a low pressure by the flow rate control device 15 of the third heat exchange unit 16b, 16c, 16d and the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch unit 11. Further, in the second heat exchanger section 16a, between the second connection section 11 and the meeting section of the second connection pipes 7b, 7c, 7d of each indoor unit side, and further in the first heat exchange section 19. Second flow control device 13
The heat exchange is performed with the refrigerant flowing into the refrigerant, and the evaporated refrigerant enters the first connecting pipe 6 and the second check valve 33, and passes through the four-way switching valve 2 of the heat source device A and the accumulator 4 to the compressor 1. Inhaled. On the other hand, the first, second and third heat exchange parts 19, 16
The refrigerant in the second branch portion 11 which has been heat-exchanged and cooled in a, 16b, 16c, and 16d and is sufficiently subcooled flows into the indoor units B and C that are about to be cooled. Conventionally, a heat pump type air conditioner in which a plurality of indoor units are connected to one heat source unit by two pipes of a gas pipe and a liquid pipe to perform cooling and heating operation is common, and each indoor unit B, All of C and D are formed to perform heating or cooling.

Next, "mainly heating in simultaneous cooling and heating operation"
The case will be described with reference to FIG. As indicated by the broken line arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 is sent to the repeater E through the four-way switching valve 2, the third check valve 34, and the second connecting pipe 7. , Gas-liquid separator 1
2, the first branch portion 10, the second electromagnetic opening / closing valve 8b,
The first connection pipes 6b and 6c on the indoor unit side are sequentially passed to flow into the indoor units B and C to be heated. And
The refrigerant exchanges heat with the indoor air in the indoor heat exchanger 5 to be condensed and liquefied to heat the room. The condensed and liquefied refrigerant is controlled by the subcool amount at the outlet of each indoor heat exchanger 5, 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. .

A part of this refrigerant passes through the second connection pipe 7d on the indoor unit side, enters the indoor unit D to be cooled, and is controlled by the superheat amount at the outlet of the indoor heat exchanger 5. After entering the flow rate control device 9 of No. 1 and being decompressed, it enters the indoor side heat exchanger 5 to exchange heat and evaporate into a gas state to cool the room, and the first connecting pipe 6d First via the electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c
Flows into the connecting pipe 6. On the other hand, the refrigerant from the second branch portion 11 has a pressure detected by the first pressure detection means 25 and a second pressure.
Through the fourth flow rate controller 17 and the second bypass pipe 14a, which are controlled so that the pressure difference from the pressure detected by the pressure detecting means 26 falls within a predetermined range, and then passes through the indoor unit D to be cooled. The fourth check valve 35 of the heat source unit A, the heat source unit side heat exchanger 3 merges with the refrigerant and passes through the thick first connection pipe 6.
Flowing in, and heat-exchanges with air to evaporate and become a gas state.

This refrigerant constitutes a circulation cycle in which it is sucked into the compressor 1 via the four-way switching valve 2 of the heat source unit A and the accumulator 4, and performs heating-main operation. At this time, the difference between the evaporation pressure in the indoor side heat exchanger 5 of the indoor unit D to be cooled and the pressure in the heat source unit side heat exchanger 3 becomes small because of switching to the thick first connection pipe 6. At this time, the indoor unit B,
The first electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c connected to C are closed, the second electromagnetic on-off valve 8b is opened, and the first electromagnetic on-off valve connected to the indoor unit D 8a and 3rd
The electromagnetic opening / closing valve 8c is opened and the second electromagnetic opening / closing valve 8b is closed. At this time, the refrigerant is the first connecting pipe 6
Is a low pressure and the second connection pipe 7 is a high pressure, so that it inevitably flows to the third check valve 34 and the fourth check valve 35.

During this cycle, part of the liquid refrigerant is the second connecting pipes 7b, 7c, 7 on the indoor unit side of the second branch portion 11.
It enters into the 1st bypass piping 14 from the meeting part of d, it is pressure-reduced to low pressure with the 3rd flow control device 15, and each indoor unit of the 2nd branching part 11 is 3rd heat exchange parts 16b, 16c, and 16d. Of the second connection pipes 7b, 7c, 7d on the side of each indoor unit and the second connection pipes 7b, 7c, 7d on the side of each indoor unit of the second branch portion 11 in the second heat exchange portion 16a. Between departments,
Further, the first heat exchange section 19 exchanges heat with the refrigerant flowing from the second flow rate control device 13 to evaporate.
The refrigerant thus evaporated enters the heat source unit side heat exchanger 3 via the first connecting pipe 6 and the fourth check valve 35, and after heat exchange with the air to evaporate and vaporize, the heat source unit A It is sucked into the compressor 1 through the four-way switching valve 2 and the accumulator 4. On the other hand, the first, second, and third heat exchange parts 19, 16a, 16
The refrigerant in the second branch portion 11, which is cooled by heat exchange with b, 16c, and 16d and is sufficiently subcooled, flows into the indoor unit D that is about to be cooled.

[0020]

Since the conventional multi-chamber heat pump type air conditioner capable of simultaneous heating and cooling operation is constructed as described above, the second state is set when the operating state is heating only or heating-based operation. The inside of the connection pipe 7 and the gas-liquid separation device 12 is filled with a high-pressure gas refrigerant, and the inside of the second connection pipe 7 and the gas-liquid separation device 12 is filled with high-pressure gas refrigerant during the cooling only or the cooling main operation. Liquid filled with two-phase refrigerant. Therefore, when the operating state is switched from the heating only or heating-main operation to the cooling only or the cooling-main operation, in order to obtain a predetermined cooling capacity in each indoor unit, the inside of the second connection pipe 7 and the gas-liquid separation are separated. The high pressure gas refrigerant in the device 12 must be rapidly displaced and replaced with high pressure, two phase refrigerant.

The present invention has been made in order to solve the above-mentioned problems, and when the operating state is switched from the heating only or heating-main operation to the cooling only or the cooling-main operation, each indoor unit has a predetermined operation. It is an object of the present invention to provide an air conditioner capable of promptly moving the high-pressure gas refrigerant in the second connection pipe or the gas-liquid separator to replace it with a two-phase refrigerant at high pressure in order to obtain the cooling capacity of .

[0022]

In order to achieve the above object, an air conditioner according to the invention of claim 1 is a compressor,
One heat source unit including a four-way switching valve, a heat source unit side heat exchanger, an accumulator, and the like, a plurality of indoor units including an indoor side heat exchanger, a first flow rate control unit, and the like, a heat source unit and a plurality of indoor units First and second connection pipes connecting the machines in parallel, and a first pipe provided in the middle of a pipe connecting one side of the indoor heat exchangers of the plurality of indoor units and the first connection pipe Solenoid on-off valve,
A second electromagnetic on-off valve provided in the middle of a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units and the second connection pipe, and an indoor heat exchanger of the plurality of indoor units A first branch portion including a third electromagnetic opening / closing valve connected in parallel to the first electromagnetic opening / closing valve and provided in the middle of a pipe connecting one side to the first connecting pipe; Second branch part for connecting the other side of the indoor side heat exchanger of the indoor unit to the second connecting pipe via the first flow rate control device, and a gas refrigerant provided in the middle of the second connecting pipe. A gas-liquid separation device for separating the liquid refrigerant and the liquid refrigerant; a second flow rate control device provided in the middle of the second connecting pipe between the lower portion of the gas-liquid separation device and the second branch portion; A first bypass pipe having a third flow rate control device, which is provided by connecting the first branch pipe and the first connection pipe, and a second branch pipe. A second bypass pipe provided by connecting the first connection pipe and the first connection pipe, and a fourth bypass pipe provided by connecting the first connection pipe and the second connection pipe by bypass connection. During the cooling mode operation in which the bypass circuit having the electromagnetic opening / closing valve and the heat-source-unit-side heat exchanger serve as a condenser, the refrigerant is circulated only from the coolant outlet side of the heat-source-unit-side heat exchanger to the second connection pipe side, and During the heating mode operation in which the refrigerant is circulated only from the connection pipe No. 1 to the four-way switching valve side and the heat exchanger on the heat source unit side becomes the evaporator, the refrigerant inflow side of the heat exchanger on the heat source unit side from the first connection pipe And a flow path switching device that allows the refrigerant to flow only through the four-way switching valve to the second connection pipe side, and a first branch portion, a second branch portion, a gas-liquid separation device, and a second flow rate. Control device, third flow control device, fourth flow control device A repeater interposed between the first bypass pipe, and the second has a bypass pipe to become the heat source apparatus and a plurality of indoor units,
When switching from heating mode operation to cooling mode operation, the second
Refrigerant replacement means for replacing the inside of the connection pipe or the inside of the gas-liquid separator with at least the gas-liquid two-phase refrigerant from the gas refrigerant.

According to the second aspect of the present invention, there is provided an air conditioner comprising: a heat source unit including a compressor, a four-way switching valve, a heat source unit side heat exchanger, an accumulator, etc., an indoor side heat exchanger, and a first flow rate. A plurality of indoor units including a control device and the like, first and second connection pipes that connect the heat source unit and the plurality of indoor units in parallel,
A first electromagnetic opening / closing valve provided in the middle of a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units and the first connection pipe, One side and second
A second solenoid on-off valve provided in the middle of a pipe connecting the first connection pipe and a second electromagnetic on-off valve provided in the middle of the pipe connecting the first connection pipe and the indoor heat exchanger of the plurality of indoor units. A first branch portion that is provided and is configured by a third electromagnetic on-off valve that is connected in parallel with the first electromagnetic on-off valve and the other side of the indoor heat exchangers of the plurality of indoor units are respectively connected to the first A second branch portion connected to the second connection pipe via the flow rate control device, a gas-liquid separation device provided in the middle of the second connection pipe for separating a gas refrigerant and a liquid refrigerant, and a gas-liquid separation device A second flow rate control device provided in the middle of the second connection pipe between the lower part of the first branch pipe and the second branch part, and a second flow control device provided by connecting the second branch part and the first connection pipe. The first bypass pipe having the flow rate control device of No. 3 is connected to the second branch portion and the first connection pipe, and the fourth bypass pipe is provided. A second bypass pipe having a quantity control device, a bypass circuit provided by connecting the first connection pipe and the second connection pipe by bypass and having a fourth electromagnetic on-off valve, and a heat source side heat exchanger During cooling mode operation as a condenser, the refrigerant is circulated only from the refrigerant outlet side of the heat source side heat exchanger to the second connection pipe side and the refrigerant is circulated only from the first connection pipe to the four-way switching valve side, In addition, during the heating mode operation in which the heat source side heat exchanger serves as an evaporator, the first
A flow path switching device that allows the refrigerant to flow only from the connection pipe to the refrigerant inflow side of the heat source side heat exchanger and allows the refrigerant to flow only from the four-way switching valve to the second connection pipe side; the first branching portion; A heat source device having two branch parts, a gas-liquid separation device, a second flow rate control device, a third flow rate control device, a fourth flow rate control device, a first bypass pipe, and a second bypass pipe. And a repeater interposed between the indoor units and a plurality of indoor units,
At the time of switching from the heating mode operation to the cooling mode operation, the fourth electromagnetic opening / closing valve of the bypass circuit is opened, and control is performed so that at least the gas-liquid two-phase refrigerant is replaced in the second connection pipe or the gas-liquid separator. And a first control means.

In the air conditioner according to the invention of claim 3, one heat source device comprising a compressor, a four-way switching valve, a heat source device side heat exchanger, an accumulator, etc., an indoor side heat exchanger, and a first flow rate. A plurality of indoor units including a control device and the like, first and second connection pipes that connect the heat source unit and the plurality of indoor units in parallel,
A first electromagnetic opening / closing valve provided in the middle of a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units and the first connection pipe, One side and second
A second solenoid on-off valve provided in the middle of a pipe connecting the first connection pipe and a second electromagnetic on-off valve provided in the middle of the pipe connecting the first connection pipe and the indoor heat exchanger of the plurality of indoor units. A first branch portion that is provided and is configured by a third electromagnetic on-off valve that is connected in parallel with the first electromagnetic on-off valve and the other side of the indoor heat exchangers of the plurality of indoor units are respectively connected to the first A second branch portion connected to the second connection pipe via the flow rate control device, a gas-liquid separation device provided in the middle of the second connection pipe for separating a gas refrigerant and a liquid refrigerant, and a gas-liquid separation device A second flow rate control device provided in the middle of the second connection pipe between the lower part of the first branch pipe and the second branch part, and a second flow control device provided by connecting the second branch part and the first connection pipe. The first bypass pipe having the flow rate control device of No. 3 is connected to the second branch portion and the first connection pipe, and the fourth bypass pipe is provided. A second bypass pipe having a quantity control device, a bypass circuit provided by connecting the first connection pipe and the second connection pipe by bypass and having a fourth electromagnetic on-off valve, and a heat source side heat exchanger During cooling mode operation as a condenser, the refrigerant is circulated only from the refrigerant outlet side of the heat source side heat exchanger to the second connection pipe side and the refrigerant is circulated only from the first connection pipe to the four-way switching valve side, In addition, during the heating mode operation in which the heat source side heat exchanger serves as an evaporator, the first
A flow path switching device that allows the refrigerant to flow only from the connection pipe to the refrigerant inflow side of the heat source side heat exchanger and allows the refrigerant to flow only from the four-way switching valve to the second connection pipe side; the first branching portion; A heat source device having two branch parts, a gas-liquid separation device, a second flow rate control device, a third flow rate control device, a fourth flow rate control device, a first bypass pipe, and a second bypass pipe. And a repeater interposed between the indoor units and a plurality of indoor units,
At the time of switching from the heating mode operation to the cooling mode operation, the second flow rate control device in the repeater and at least one other flow rate control device are opened so that at least the second connection pipe or the gas-liquid separation device is opened. Second control means for controlling so as to replace with the gas-liquid two-phase refrigerant.

In the air conditioner according to the invention of claim 4, one heat source device comprising a compressor, a four-way switching valve, a heat source device side heat exchanger, an accumulator, etc., an indoor side heat exchanger, and a first flow rate. A plurality of indoor units including a control device and the like, first and second connection pipes that connect the heat source unit and the plurality of indoor units in parallel,
A first electromagnetic opening / closing valve provided in the middle of a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units and the first connection pipe, One side and second
A second solenoid on-off valve provided in the middle of a pipe connecting the first connection pipe and a second electromagnetic on-off valve provided in the middle of the pipe connecting the first connection pipe and the indoor heat exchanger of the plurality of indoor units. A first branch portion that is provided and is configured by a third electromagnetic on-off valve that is connected in parallel with the first electromagnetic on-off valve and the other side of the indoor heat exchangers of the plurality of indoor units are respectively connected to the first A second branch portion connected to the second connection pipe via the flow rate control device, a gas-liquid separation device provided in the middle of the second connection pipe for separating a gas refrigerant and a liquid refrigerant, and a gas-liquid separation device A second flow rate control device provided in the middle of the second connection pipe between the lower part of the first branch pipe and the second branch part, and a second flow control device provided by connecting the second branch part and the first connection pipe. The first bypass pipe having the flow rate control device of No. 3 is connected to the second branch portion and the first connection pipe, and the fourth bypass pipe is provided. A second bypass pipe having a quantity control device, a bypass circuit provided by connecting the first connection pipe and the second connection pipe by bypass and having a fourth electromagnetic on-off valve, and a heat source side heat exchanger During cooling mode operation as a condenser, the refrigerant is circulated only from the refrigerant outlet side of the heat source side heat exchanger to the second connection pipe side and the refrigerant is circulated only from the first connection pipe to the four-way switching valve side, In addition, during the heating mode operation in which the heat source side heat exchanger serves as an evaporator, the first
A flow path switching device that allows the refrigerant to flow only from the connection pipe to the refrigerant inflow side of the heat source side heat exchanger and allows the refrigerant to flow only from the four-way switching valve to the second connection pipe side; the first branching portion; A heat source device having two branch parts, a gas-liquid separation device, a second flow rate control device, a third flow rate control device, a fourth flow rate control device, a first bypass pipe, and a second bypass pipe. And a repeater interposed between the indoor units and a plurality of indoor units,
When switching from heating mode operation to cooling mode operation, the first
And a third control means for controlling so as to open the electromagnetic on-off valve and the second electromagnetic on-off valve and replace at least the gas-liquid two-phase refrigerant in the second connection pipe or in the gas-liquid separation device. It is a thing.

According to the fifth aspect of the present invention, in the air conditioner, one heat source unit including a compressor, a four-way switching valve, a heat source unit side heat exchanger, an accumulator, etc., an indoor side heat exchanger, and a first flow rate are provided. A plurality of indoor units including a control device and the like, first and second connection pipes that connect the heat source unit and the plurality of indoor units in parallel,
A first electromagnetic opening / closing valve provided in the middle of a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units and the first connection pipe, One side and second
A second solenoid on-off valve provided in the middle of a pipe connecting the first connection pipe and a second electromagnetic on-off valve provided in the middle of the pipe connecting the first connection pipe and the indoor heat exchanger of the plurality of indoor units. Is provided and is connected in parallel with the first solenoid valve
The first branch part composed of a third electromagnetic on-off valve having an opening diameter smaller than that of the electromagnetic on-off valve and the other side of the indoor heat exchangers of the plurality of indoor units, respectively. A second branch part connected to the second connection pipe via the second connection pipe, a gas-liquid separation device provided in the middle of the second connection pipe for separating a gas refrigerant and a liquid refrigerant, and a lower part of the gas-liquid separation device and a first part. A second flow rate control device provided in the middle of the second connection pipe between the second branch part and the third flow rate control device provided by connecting the second branch part and the first connection pipe. A first bypass pipe having a device, a second bypass pipe provided by connecting the second branch portion and the first connection pipe and having a fourth flow rate control device, a first connection pipe and a first bypass pipe A bypass circuit having a fourth electromagnetic on-off valve provided by bypass connection with the second connection pipe, and a heat source side heat exchanger During cooling mode operation as a condenser, the refrigerant is circulated only from the refrigerant outlet side of the heat source side heat exchanger to the second connection pipe side and the refrigerant is circulated only from the first connection pipe to the four-way switching valve side, In addition, during the heating mode operation in which the heat source side heat exchanger serves as an evaporator, the refrigerant is circulated from the first connection pipe only to the refrigerant inflow side of the heat source side heat exchanger, and the four-way switching valve is connected to the second connection pipe. Flow path switching device that allows the refrigerant to flow only to the first side, first branch part, second branch part, gas-liquid separation device, second flow rate control device, third flow rate control device, fourth flow rate control device A repeater having a first bypass pipe and a second bypass pipe and interposed between the heat source unit and a plurality of indoor units;
When switching from heating mode operation to cooling mode operation, the second
And a fourth control means for controlling so that the inside of the second connecting pipe or the inside of the gas-liquid separation device is replaced with at least the gas-liquid two-phase refrigerant. It is a thing.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the air conditioner of the present invention will be described below. FIG. 1 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to an embodiment of the present invention. 2 to 4 show operating states of the air conditioner of FIG. 1 during cooling and heating operations, and FIG. 2 is an operating state diagram of only cooling or only heating, and FIGS.
3 shows the operation of the cooling and heating simultaneous operation, FIG. 3 is an operation mainly showing cooling (when the cooling operation capacity is larger than the heating operation capacity), and FIG. 4 is an operation showing heating mainly (when the heating operation capacity is larger than the cooling operation capacity) It is an operation state diagram. It should be noted that here, a case where three indoor units are connected to one heat source device 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, which will be described later, and have the same structure. As will be described later, E is a first branch unit 10, a second flow rate control device 13, and a second branch unit 1.
1, gas-liquid separator 12, second heat exchange section 16a, third heat exchange sections 16b, 16c, 16d, first heat exchange section 1
9, third flow controller 15, fourth flow controller 17
It is a repeater with a built-in. Further, 1 is a compressor, 2 is a four-way switching valve that switches the flow direction of the refrigerant from the compressor 1, 3 is a heat source side heat exchanger, 4 is an accumulator, and is connected to the compressor 1 via the four-way switching valve 2. ing. The heat source machine A is constructed from these. 5 is three indoor units B,
Indoor heat exchangers 6 respectively provided in C and D, and a thick first connecting pipe 6 for connecting the four-way switching valve 2 of the heat source unit A and the relay unit E via a second check valve 33 described later. , 6b, 6
Reference numerals c and 6d respectively connect the indoor heat exchangers 5 of the indoor units B, C and D and the relay unit E, and the indoor unit side first connection pipes corresponding to the first connection pipes 6, and 7 is a heat source. The heat source unit side heat exchanger 3 of the machine A and the relay unit E are connected via a first check valve 32, which will be described later, and are second connection pipes thinner than the first connection pipe 6.

Reference numerals 7b, 7c and 7d respectively connect the indoor heat exchangers 5 of the indoor units B, C and D and the relay unit E via the first flow control device 9, and the second connecting pipes. 7 is a second connection pipe on the indoor unit side corresponding to 7. Reference numeral 8a denotes the first connection pipes 6b, 6c, 6d on the indoor unit side and the first connection pipe 6
Is a first solenoid on-off valve for opening and closing the circuit with, and 8b is the first connection pipes 6b, 6c, 6d on the indoor unit side and the second connection pipe 7
Is a second electromagnetic on-off valve for opening and closing the circuit, and 8c is a third electromagnetic on-off valve connected in parallel with the first electromagnetic on-off valve 8a and having an opening diameter smaller than that of the first electromagnetic on-off valve 8a. 9 is connected to each of the indoor heat exchangers 5 in close proximity to each other, and during cooling, due to the superheat amount on the outlet side of the indoor heat exchanger 5,
At the time of heating, the first flow rate control device is controlled by the subcool amount, and is connected to the second connection pipes 7b, 7c, 7d on the indoor unit side. 10 is the above-mentioned first solenoid on-off valve 8a
And a second electromagnetic opening / closing valve 8b and a third electromagnetic opening / closing valve 8c. Reference numeral 11 denotes a second branch portion including the second connection pipes 7b, 7c, 7d on the indoor unit side and the second connection pipe 7. Reference numeral 12 is a gas-liquid separator provided in the middle of the second connecting pipe 7, the gas phase portion of which is connected to the first electromagnetic on-off valve 8a of the first branch portion 10 and the liquid phase portion of which is the second Is connected to the branch part 11. Reference numeral 13 denotes a second flow rate control device (here, an electric expansion valve) that is provided between the gas-liquid separation device 12 and the second branch portion 11 and can be opened and closed.

Reference numeral 14 is a first bypass pipe connecting the second branch portion 11 and the first connection pipe 6, and 15 is a third flow rate control device (here, a third flow control device) provided in the middle of the first bypass pipe 14. (Electrical expansion valve), 16a is the first bypass pipe 14
It is provided downstream of the third flow rate control device 15 on the way and
Second connection pipe 7 on each indoor unit side in branch portion 11 of
It is a second heat exchanging part for exchanging heat with the meeting parts of b, 7c and 7d. 16b, 16c, 16d are respectively provided on the downstream side of the third flow rate control device 15 provided in the middle of the first bypass pipe 14, and the second branch portion 1 is provided.
The second connection pipes 7b, 7c, 7 on the indoor unit side in FIG.
It is a third heat exchanging section for exchanging heat with the d. 19 is a pipe that is provided in the first bypass pipe 14 downstream of the third flow rate controller 15 and downstream of the second heat exchange unit 16a, and connects the gas-liquid separator 12 and the second flow rate controller 13 to each other. A first heat exchange section for exchanging heat with
Reference numeral 7 denotes a fourth flow rate control device (here, an electric expansion valve) that is openable and closable provided in the middle of the second bypass pipe 14a that connects the second branch portion 11 and the first connection pipe 6.

On the other hand, reference numeral 32 is a first check valve provided between the heat source unit side heat exchanger 3 and the second connecting pipe 7, which connects the heat source unit side heat exchanger 3 to the second connecting pipe. Allow the refrigerant flow only to 7. Reference numeral 33 is a second check valve provided between the four-way switching valve 2 of the heat source unit A and the first connecting pipe 6, and is a first check valve.
From the connection pipe 6 to the four-way switching valve 2 only. Reference numeral 34 denotes the four-way switching valve 2 of the heat source unit A and the second connection pipe 7
Is a third check valve provided between the four-way switching valve 2 and
To the second connection pipe 7 only. 35
Is a fourth check valve provided between the heat source device side heat exchanger 3 and the first connection pipe 6, and the refrigerant flows only from the first connection pipe 6 to the heat source device side heat exchanger 3. Tolerate. The above-mentioned first, second, third, and fourth check valves 32, 33, 34, 3
The flow path switching device 40 is composed of the combination structure of No. 5.
Further, 49 is a bypass circuit that connects the first connection pipe 6 and the second connection pipe 7, and 48 is a fourth electromagnetic circuit that is provided in the middle of the bypass circuit 49 and that controls the opening and closing of the bypass circuit 49. It is an on-off valve.

Reference numeral 25 is a first pressure detecting means provided between the first branch portion 10 and the second flow rate control device 13, and 26.
Is a second pressure detecting means provided between the second flow rate control device 13 and the fourth flow rate control device 17. Reference numeral 50 is an indoor unit operating capacity detecting means for detecting the operating capacity of each indoor unit B, C, D. Further, 51 is a four-way switching valve 2 based on a detection signal from the indoor unit motion capacity detecting means 50.
Is operated to switch the operation mode, and at the same time, the fourth electromagnetic on-off valve 48, the second flow rate control device 13, the third flow rate control device 15, the fourth flow rate control device 17, the first electromagnetic on-off valve 8a, Control means for controlling the opening / closing of the second electromagnetic opening / closing valve 8b and the third electromagnetic opening / closing valve 8c (refrigerant replacement means in the present invention,
(One example of each of the first, second, third, and fourth control means)
It is.

Next, the operation will be described. First, the case of "only cooling operation" will be described with reference to FIG. As indicated by the solid line 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 with air in the heat-source-unit-side heat exchanger 3, and is condensed. Check valve 3 of 1
2, the second connection pipe 7, the gas-liquid separation device 12, the second flow rate control device 13 in this order, and then the second branch portion 11 and the second connection pipes 7b, 7c, 7d on the indoor unit side. , Into each indoor unit B, C, D. The refrigerant flowing into each indoor unit B, C, D is decompressed 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 It heats and exchanges heat with the room air, is gasified, and cools the room.

The refrigerant in the gas state is used as the first connection pipes 6b, 6c, 6d on the indoor unit side and the first solenoid on-off valve 8.
a and the third electromagnetic opening / closing valve 8c, the first branch portion 10, the first connecting pipe 6, the second check valve 33, the four-way switching valve 2 of the heat source device A, and the accumulator 4 to suck in the compressor 1. The cooling cycle is configured and the cooling operation is performed. At this time, the first
The electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c are opened, and the second electromagnetic control valve 8b is closed. At this time, the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, so that the refrigerant inevitably flows through the first check valve 32 and the second check valve 33. . Also, during this cycle, the second
Part of the refrigerant that has passed through the flow rate control device 13 enters the first bypass pipe 14 and is depressurized to a low pressure by the third flow rate control device 15, and then the second branch is performed by the third heat exchange units 16b, 16c, 16d. The second connection pipes 7b, 7 on the indoor unit side of the section 11
c, 7d and the second heat exchange section 16
The second connection pipe 7 on the side of each indoor unit of the second branch portion 11 is a.
Between b, 7c and 7d, the first heat exchange section 19
The heat exchange with the refrigerant flowing into the flow rate control device 13 is performed and the heat is evaporated. The refrigerant thus evaporated enters the first connecting pipe 6 and the second check valve 33, and is sucked into the compressor 1 via the four-way switching valve 2 of the heat source unit A and the accumulator 4.

On the other hand, the first, second and third heat exchange parts 19,
The refrigerant in the second branch portion 11, which is cooled by heat exchange with 16a, 16b, 16c, 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 heating operation" will be described with reference to FIG. As shown by the broken line arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, the third check valve 34, the second connecting pipe 7, the gas-liquid separation device 12 Through the first branch portion 10, the second electromagnetic opening / closing valve 8b, and the first connection pipes 6b, 6c, 6d on the indoor unit side.
Through each of the indoor units B, C, and D, and exchanges heat with indoor air to be condensed and liquefied to heat the room.

The refrigerant in this 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 then the second connection on the indoor unit side. From the pipes 7b, 7c and 7d, they flow into the second branch portion 11 and merge, and further pass through the fourth flow rate control device 17. Here, the refrigerant is decompressed by the first flow control device 9 or the third and fourth flow control devices 15 and 17 to a low-pressure gas-liquid two-phase state. The refrigerant decompressed to a low pressure flows from the second bypass pipe 14a through the first connecting pipe 6 into the fourth check valve 35 of the heat source device A and the heat source device side heat exchanger 3 to exchange heat with the air. Then, it is vaporized into a gas state, forms a circulation cycle in which it is sucked into the compressor 1 through the four-way switching valve 2 of the heat source unit A and the accumulator 4, and the heating operation is performed. At this time, the first electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c are closed, and the second electromagnetic on-off valve 8c is closed.
The solenoid on-off valve 8b of is open. At this time, the refrigerant has a high pressure in the first connecting pipe 6 and the second connecting pipe 7
Is low pressure, so that the third check valve 34 and the fourth check valve 35 necessarily flow.

Next, the case of "mainly cooling in simultaneous cooling and heating operation" will be described with reference to FIG. As shown by the solid arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 flows into the heat source unit side heat exchanger 3 through the four-way switching valve 2 and exchanges heat with air to form a gas-liquid two-phase. It becomes a high temperature and high pressure state. After that, the two-phase high-temperature high-pressure refrigerant is sent to the gas-liquid separation device 12 of the relay machine E through the first check valve 32 and the second connection pipe 7. Here, the gaseous refrigerant is separated into a gaseous refrigerant and a liquid refrigerant, and the separated gaseous refrigerant sequentially passes through the first branch portion 10, the second electromagnetic opening / closing valve 8b, and the first connection pipe 6d on the indoor unit side, It flows into the indoor unit D to be heated, heat-exchanges with the indoor air in the indoor heat exchanger 5 to be condensed and liquefied, and heats the room. Further, it is controlled by the amount of subcool at the outlet of the indoor heat exchanger 5, passes through the first flow rate control device 9 in a substantially fully opened state, and is slightly decompressed to the second branch portion 1.
Flow into 1.

On the other hand, the remaining liquid refrigerant passes through the second flow rate control device 13 which is controlled by the pressure detected by the first pressure detecting means 25 and the pressure detected by the second pressure detecting means 26, and passes through the second flow rate control device 13. It flows into the branch portion 11 and merges with the refrigerant that has passed through the indoor unit D that is going to be heated. Then, the combined refrigerant is used as the second branch portion 11 and the second connection pipe 7 on the indoor unit side.
It flows into each indoor unit B, C in order of b, 7c. The refrigerant flowing into each indoor unit B, C is depressurized to a low pressure by the first flow rate control device 9 controlled by the superheat amount at the outlet of the indoor unit heat exchanger 5, and then the indoor heat exchanger 5 Flows into the room, heat exchanges with the room air, evaporates and is gasified, and cools the room. Further, the refrigerant in the gas state passes through the first connection pipes 6b and 6c on the indoor unit side, the first electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c, the first branch portion 10, A circulation cycle in which the compressor 1 is sucked through the connecting pipe 6 of the first unit, the second check valve 33, the four-way switching valve 2 of the heat source unit A, and the accumulator 4 constitutes a cooling main operation. Further, here, the first electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c connected to the indoor units B and C are opened, and the second electromagnetic on-off valve 8c is opened.
The electromagnetic opening / closing valve 8b is closed, the first electromagnetic opening / closing valve 8a and the third electromagnetic opening / closing valve 8c connected to the indoor unit D are closed, and the second electromagnetic opening / closing valve 8b is opened. At this time, since the first connecting pipe 6 has a low pressure and the second connecting pipe 7 has a high pressure, the refrigerant necessarily flows through the first check valve 32 and the second check valve 33.

During this cycle, part of the liquid refrigerant is the second connecting pipes 7b, 7c on the indoor unit side of the second branch portion 11,
Enter the first bypass pipe 14 from the meeting point of 7d,
The pressure is reduced to a low pressure by the flow rate control device 15 of the third heat exchange unit 16b, 16c, 16d and the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch unit 11. Further, in the second heat exchanger section 16a, between the second connection section 11 and the meeting section of the second connection pipes 7b, 7c, 7d of each indoor unit side, and further in the first heat exchange section 19. Second flow control device 13
The heat exchange is performed with the refrigerant flowing into the refrigerant, and the evaporated refrigerant enters the first connecting pipe 6 and the second check valve 33, and passes through the four-way switching valve 2 of the heat source device A and the accumulator 4 to the compressor 1. Inhaled. On the other hand, the first, second and third heat exchange parts 19, 16
The refrigerant in the second branch portion 11 which has been heat-exchanged and cooled in a, 16b, 16c, and 16d and is sufficiently subcooled flows into the indoor units B and C that are about to be cooled.

Next, the case of "mainly heating in simultaneous cooling and heating operation" will be described with reference to FIG. As shown by the broken line arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2 and the third check valve 34 and the second check valve 34.
Is sent to the repeater E through the connection pipe 7 of the first branch portion 10 and the second solenoid opening / closing valve 8 through the gas-liquid separation device 12.
b, through the first connection pipes 6b, 6c on the indoor unit side in order,
It flows into each of the indoor units B and C that are going to be heated. Then, the refrigerant exchanges heat with the indoor air in the indoor heat exchanger 5 to be condensed and liquefied to heat the room. The condensed and liquefied refrigerant 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,
It is slightly decompressed and flows into the second branch portion 11.

Part of this refrigerant passes through the second connection pipe 7d on the indoor unit side, enters the indoor unit D to be cooled, and is controlled by the superheat amount at the outlet of the indoor heat exchanger 5. After entering the flow rate control device 9 of No. 1 and being decompressed, it enters the indoor side heat exchanger 5 to exchange heat and evaporate into a gas state to cool the room, and the first connecting pipe 6d First via the electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c
Flows into the connecting pipe 6. On the other hand, the refrigerant from the second branch portion 11 has a pressure detected by the first pressure detection means 25 and a second pressure.
Through the fourth flow rate controller 17 and the second bypass pipe 14a, which are controlled so that the pressure difference from the pressure detected by the pressure detecting means 26 falls within a predetermined range, and then passes through the indoor unit D to be cooled. The fourth check valve 35 of the heat source unit A, the heat source unit side heat exchanger 3 merges with the refrigerant and passes through the thick first connection pipe 6.
Flowing in, and heat-exchanges with air to evaporate and become a gas state.

This refrigerant constitutes a circulation cycle in which it is sucked into the compressor 1 via the four-way switching valve 2 of the heat source unit A and the accumulator 4, and performs heating-main operation. At this time, the difference between the evaporation pressure in the indoor side heat exchanger 5 of the indoor unit D to be cooled and the pressure in the heat source unit side heat exchanger 3 becomes small because of switching to the thick first connection pipe 6. At this time, the indoor unit B,
The first electromagnetic on-off valve 8a and the third electromagnetic on-off valve 8c connected to C are closed, the second electromagnetic on-off valve 8b is opened, and the first electromagnetic on-off valve connected to the indoor unit D 8a and 3rd
The electromagnetic opening / closing valve 8c is opened and the second electromagnetic opening / closing valve 8b is closed. At this time, the refrigerant is the first connecting pipe 6
Is a low pressure and the second connection pipe 7 is a high pressure, so that it inevitably flows to the third check valve 34 and the fourth check valve 35.

During this cycle, part of the liquid refrigerant is the second connecting pipes 7b, 7c on the indoor unit side of the second branch portion 11,
Enter the first bypass pipe 14 from the meeting point of 7d,
The pressure is reduced to a low pressure by the flow rate control device 15 of the third heat exchange unit 16b, 16c, 16d and the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch unit 11. In addition, in the second heat exchange section 16a, between the second connection section 11 and the connection section of the second connection pipes 7b, 7c, 7d on the indoor unit side, and further in the first heat exchange section 19, 2 flow control device 13
The heat exchange is performed between the refrigerant and the refrigerant flowing in to evaporate. The refrigerant thus evaporated enters the heat source unit side heat exchanger 3 via the first connecting pipe 6 and the fourth check valve 35, and after heat exchange with the air to evaporate and vaporize, the heat source unit A It is sucked into the compressor 1 through the four-way switching valve 2 and the accumulator 4. On the other hand, the first, second and third heat exchange parts 19, 16
The refrigerant in the second branch portion 11, which is cooled by heat exchange with a, 16b, 16c, and 16d and is sufficiently subcooled, flows into the indoor unit D that is about to be cooled.

FIG. 5 is a control flowchart in the air conditioner according to the first and second aspects of the invention.
The present embodiment will be described with reference to the above flowchart executed by the control means 51. During the operation of the compressor 1 in all heating or heating only (the mode in which the heat-source-unit-side heat exchanger 3 becomes an evaporator like this is hereinafter referred to as heating mode), the indoor unit operating capacity is determined in step S51. The detecting means 50 detects the operating capacity of each indoor unit B, C, D. The operating capacity of the indoor unit is, for example, the maximum capacity of each indoor unit, the number of operating units,
It is calculated and detected based on the operation mode (cooling operation or heating operation) or the like. Next, in step S52, step S
Based on the indoor unit operating capacity detected in 51, it is determined whether the heating operating capacity is larger than the cooling operating capacity, and if the cooling operating capacity is larger than the heating operating capacity, the process proceeds to step S53, and all cooling or cooling main As described above, the mode in which the heat-source-unit-side heat exchanger 3 serves as a condenser is switched to a cooling mode). After switching the operation mode in step S53, the fourth electromagnetic on-off valve 48 in the bypass circuit 49 is opened in step S54. This allows
The high pressure gas refrigerant in the second connection pipe 7 and the gas-liquid separation device 12 is transferred to the first connection pipe 6 through which the low pressure gas refrigerant flows by the bypass circuit 49. As a result, the high-pressure two-phase refrigerant condensed by exchanging heat with the air in the heat-source-unit-side heat exchanger 3 can quickly flow into the second connection pipe 7 and the gas-liquid separation device 12. Therefore, the liquid refrigerant separated by the gas-liquid separator 12 is fed to the first flow controller 9
Since it can be poured into the indoor heat exchanger 5 of the indoor unit to be cooled, a predetermined cooling capacity can be promptly drawn out. Then, in step S55, it is determined whether or not the opening time of the first bypass circuit has passed a predetermined time such that transfer of the gas refrigerant from the second connecting pipe 7 or the gas-liquid separation device 12 is completed. If so, the fourth electromagnetic opening / closing valve 48 is closed in order to close the bypass circuit 49 in step S56.

Also, in the first embodiment, step S55.
Although the time is used as the criterion in the above, the same effect can be obtained by using the temperature or pressure as the criterion instead of the time.

Example 2. The present embodiment relates to the inventions of claims 1 and 3, and the overall configuration diagram centering on the refrigerant system of the air conditioner is the same as that of FIG.

FIG. 6 is a control flowchart in the air conditioner according to the first and third aspects of the invention.
The present embodiment will be described with reference to the above flowchart executed by the control means 51. While the compressor 1 is operating in the heating mode, the indoor unit operating capacity detecting means 50 is operated in step S61.
Detects the operating capacity of the indoor unit. Next, step S6
In 2, it is determined whether the heating operation capacity is larger than the cooling operation capacity based on the indoor unit operation capacity detected in step S61.
If the cooling operation capacity is larger than the heating operation capacity, the process proceeds to step S63 to switch to the cooling mode operation. After switching the operation mode in step S63, step S64
Then, the second flow rate control device 13 and the third flow rate control device 15 provided in the second branch portion 11 in the relay device E are opened, and the high pressure in the second connection pipe 7 and the gas-liquid separation device 12 is increased. The first connection pipe 6 through which the low-pressure gas refrigerant flows
Shift to. As a result, the high-pressure two-phase refrigerant condensed by exchanging heat with the air in the heat source unit side heat exchanger 3 can quickly flow into the second connecting pipe 7 and the gas-liquid separation device 12. Therefore, the liquid refrigerant separated by the gas-liquid separation device 12 can be poured into the indoor heat exchanger 5 of the cooling indoor unit via the first flow rate control device 9, so that a predetermined cooling capacity can be promptly drawn out. be able to. afterwards,
In step S65, it is determined whether or not the time during which the second flow rate control device 13 and the third flow rate control device 15 are open has exceeded a predetermined time, and if they have passed, a second time is determined in step S66. The flow rate control device 13 and the third flow rate control device 15 are returned to normal control.

In the second embodiment, instead of opening the third flow control device 15, the fourth flow control device 17 may be opened, or the third flow control device 15 and the fourth flow control device 15 may be opened.
Even if both of the flow rate control devices 17 are opened, the effect can be obtained.

Also, in the second embodiment, step S65.
Although the time is used as the criterion in the above, the same effect can be obtained by using the temperature or pressure as the criterion instead of the time.

Embodiment 3 FIG. The present embodiment relates to the inventions of claims 1 and 4, and the overall configuration diagram centering on the refrigerant system of the air conditioner is the same as that of FIG.

FIG. 7 is a control flowchart in the air conditioner according to the inventions of claims 1 and 4.
The present embodiment will be described with reference to the above flowchart executed by the control means 51. During operation of the compressor 1 in the heating mode, the indoor unit operating capacity detection means 50 is operated in step S71.
Detects the operating capacity of each indoor unit B, C, D. next,
In step S72, it is determined whether or not the heating operation capacity is larger than the cooling operation capacity based on the indoor unit operation capacity detected in step S71. If the cooling operation capacity is larger than the heating operation capacity, the process proceeds to step S73, and the cooling mode operation is performed. Switch to. After switching the operation mode in step S73, in step S74, the first electromagnetic opening / closing valve 8a and the second electromagnetic opening / closing valve 8 provided in the first branch portion 10 in the relay device E are connected.
b is opened, and the high pressure gas refrigerant in the second connection pipe 7 and the gas-liquid separation device 12 is transferred to the first connection pipe 6 through which the low pressure gas refrigerant flows. As a result, the high-pressure two-phase refrigerant condensed by exchanging heat with the air in the heat source side heat exchanger 3 can quickly flow into the second connecting pipe 7 and the gas-liquid separation device 12. Therefore, the liquid refrigerant separated by the gas-liquid separation device 12 can be poured into the indoor heat exchanger 5 of the cooling indoor unit via the first flow rate control device 9.
It is possible to promptly bring out the predetermined cooling capacity. After that, in step S75, it is determined whether or not the time during which the first electromagnetic opening / closing valve 8a and the second electromagnetic opening / closing valve 8b are opened has exceeded a predetermined time, and if so, in step S76. The first electromagnetic on-off valve 8a and the second electromagnetic on-off valve 8b are returned to normal control.

In the third embodiment, step S75
Although the time is used as the criterion in the above, the same effect can be obtained by using the temperature or pressure as the criterion instead of the time.

Embodiment 4 FIG. The present embodiment relates to the inventions of claims 1 and 5, and the overall configuration diagram centering on the refrigerant system of the air conditioner is the same as that of FIG.

FIG. 8 is a control flowchart in the air conditioner according to the inventions of claims 1 and 5. The present embodiment will be described with reference to the above flowchart executed by the control means 51. During operation of the compressor 1 in the heating mode, in step S81, the indoor unit operating capacity detection means 50 detects the operating capacity of the indoor unit. Next, step S82.
Then, it is determined whether or not the heating operation capacity is larger than the cooling operation capacity based on the indoor unit operation capacity detected in step S81. If the cooling operation capacity is larger than the heating operation capacity, the process proceeds to step S83 to switch to the cooling mode operation. . After switching the operation mode in step S83, in step S84, the second electromagnetic opening / closing valve 8b and the third electromagnetic opening / closing valve 8c provided in the first branch portion 10 in the relay device E are opened, and the second electromagnetic opening / closing valve 8c is opened.
The high-pressure gas refrigerant in the connection pipe 7 and the gas-liquid separation device 12 is transferred to the first connection pipe 6 in which the low-pressure gas refrigerant flows. As a result, the high-pressure two-phase refrigerant condensed by exchanging heat with the air in the heat source side heat exchanger 3 is quickly transferred to the second
Can be poured into the connecting pipe 7 and the gas-liquid separation device 12. Therefore, the liquid refrigerant separated by the gas-liquid separation device 12 can be poured into the indoor heat exchanger 5 of the cooling indoor unit via the first flow rate control device 9, so that a predetermined cooling capacity can be promptly drawn out. be able to. After that, in step S85, it is determined whether or not the time during which the second electromagnetic opening / closing valve 8b and the third electromagnetic opening / closing valve 8c are opened has exceeded a predetermined time, and if so, in step S86. The second electromagnetic opening / closing valve 8b and the third electromagnetic opening / closing valve 8c are returned to normal control.

In the fourth embodiment, step S85
Although the time is used as the criterion in the above, the same effect can be obtained by using the temperature or pressure as the criterion instead of the time.

[0057]

As described above, according to the first aspect of the present invention, when the operating state is switched from the heating mode operation of heating only or heating-main operation to the cooling only operation of cooling only or cooling-main operation, the refrigerant circuit is operated. By moving the gas refrigerant from the second connection pipe in the inside or the gas-liquid separator and replacing it with at least the gas-liquid two-phase refrigerant, it is possible to promptly bring out the predetermined cooling capacity.

According to the second invention, at the time of switching from the heating mode operation of the heating only or the heating main operation to the cooling mode operation of the cooling only or the cooling main operation, the fourth electromagnetic on-off valve of the bypass circuit is opened, By replacing at least the gas-liquid two-phase refrigerant in the second connection pipe or the gas-liquid separation device, it is possible to relatively easily and quickly bring out the predetermined cooling capacity.

According to the third invention, at the time of switching from the heating mode operation of the heating only or the heating main operation to the cooling mode operation of the cooling only or the cooling main operation, at least the second flow rate control device in the repeater and at least another By opening one or more flow rate control devices and replacing at least the gas-liquid two-phase refrigerant in the second connection pipe or the gas-liquid separation device, it is possible to promptly bring out the predetermined cooling capacity. Further, since the flow control device has a small opening diameter and gradually opens by pulse control, it is possible to prevent the generation of refrigerant noise.

According to the fourth aspect of the invention, when the heating mode operation of the heating only or the heating main operation is switched to the cooling mode operation of the cooling only or the cooling main operation, the first electromagnetic on-off valve and the second electromagnetic on-off valve. By opening and replacing the inside of the second connection pipe or the inside of the gas-liquid separation device with at least a gas-liquid two-phase refrigerant, a predetermined cooling capacity can be promptly drawn out. Further, by transferring the refrigerant from the gas side of the gas-liquid separator, it is possible to prevent the liquid refrigerant necessary for the cooling operation from being transferred with the gas.

According to the fifth invention, when the heating mode operation of the heating only or the heating main operation is switched to the cooling mode operation of the cooling only or the cooling main operation, the second electromagnetic opening / closing valve and the third electromagnetic opening / closing valve are provided. By opening and replacing the inside of the second connection pipe or the inside of the gas-liquid separation device with at least a gas-liquid two-phase refrigerant, a predetermined cooling capacity can be promptly drawn out. Further, by transferring the refrigerant from the gas side of the gas-liquid separator, it is possible to prevent the liquid refrigerant necessary for the cooling operation from being transferred with the gas, and to prevent the third solenoid on-off valve having a small opening diameter. By using it, it is possible to prevent the generation of refrigerant noise.

[Brief description of drawings]

FIG. 1 is a diagram showing the structure of claim 1, claim 2, claim 3, claim 4,
FIG. 7 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to an embodiment of the invention of claim 5.

2 is an operation state diagram showing a flow of a refrigerant during a cooling only or heating only operation by the air-conditioning apparatus of FIG. 1. FIG.

FIG. 3 is an operation state diagram showing the flow of the refrigerant during the cooling-main operation in the cooling / heating simultaneous operation of the air conditioner of FIG. 1.

FIG. 4 is an operation state diagram showing a refrigerant flow during a heating-main operation in a simultaneous heating / cooling operation of the air-conditioning apparatus of FIG. 1.

FIG. 5 is a control flowchart of the air conditioner according to an embodiment of the inventions of claims 1 and 2.

FIG. 6 is a control flowchart of the air conditioner according to an embodiment of the inventions of claims 1 and 3.

FIG. 7 is a control flowchart of the air conditioner according to an embodiment of the inventions of claims 1 and 4.

FIG. 8 is a control flowchart of an air conditioner according to an embodiment of the inventions of claims 1 and 5.

FIG. 9 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a conventional technique.

FIG. 10 is an operation state diagram showing the flow of the refrigerant at the time of cooling only or heating only by the air conditioner of the related art.

FIG. 11 is an operation state diagram showing the flow of the refrigerant during the cooling-main operation in the simultaneous cooling and heating operation by the conventional air conditioner.

FIG. 12 is an operation state diagram showing the flow of the refrigerant during heating-main operation in simultaneous heating and cooling operation by the air conditioner of the conventional technique.

[Explanation of symbols]

A heat source unit, B indoor unit, C indoor unit, D indoor unit, E
Repeater, 1 compressor, 2 4-way switching valve, 3 heat source side heat exchanger, 4 accumulator, 5 indoor heat exchanger,
6 1st connection piping, 6b 1st indoor connection piping,
6c First connection pipe on the indoor side, 7 Second connection pipe,
7b 2nd indoor connection pipe, 7c 2nd indoor connection pipe, 8a 1st solenoid valve, 8b 2nd solenoid valve, 8c 3rd solenoid valve, 9 1st flow control Device, 10 1st branch part, 11 2nd branch part, 12 Gas-liquid separation device, 13 2nd flow control device, 14 1st bypass piping, 14a 2nd bypass piping, 15 3rd flow control Device, 17 Fourth flow controller, 40
Flow path switching device, 48 Fourth electromagnetic opening / closing valve, 49 Bypass circuit, 50 Indoor unit operating capacity detecting means, 51 Control means.

Claims (5)

[Claims] 1. A heat source unit including a compressor, a four-way switching valve, a heat source unit side heat exchanger, an accumulator, and the like, and a plurality of indoor units including an indoor side heat exchanger, a first flow controller, and the like. And first and second connection pipes that connect the heat source unit and the plurality of indoor units in parallel, one side of the indoor heat exchanger of the plurality of indoor units, and the first connection pipe A first electromagnetic on-off valve provided in the middle of a pipe connecting to, a first side of the indoor heat exchanger of the plurality of indoor units and the second
Second solenoid on-off valve provided in the middle of a pipe connecting the above-mentioned connection pipe and a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units to the first connection pipe A first branch portion formed of a third electromagnetic on-off valve connected in parallel with the first electromagnetic on-off valve provided in the middle of
A second branch portion that connects the other side of the indoor heat exchanger of the plurality of indoor units to the second connection pipe via the first flow rate control device, and the second connection pipe. And a gas-liquid separator for separating a gas refrigerant and a liquid refrigerant, provided in the middle of the second connecting pipe between the lower portion of the gas-liquid separator and the second branch portion. A first flow rate control device, a first flow rate control device that is provided by connecting the second branch portion and the first connection pipe to each other, and has a third flow rate control device.
Bypass pipe, a second bypass pipe provided by connecting the second branch portion and the first connection pipe, and having a fourth flow rate control device, the first connection pipe, and the second bypass pipe.
In the cooling mode operation in which the bypass circuit having the fourth electromagnetic on-off valve provided by bypass connection with the connection pipe of No. 1 and the heat source unit side heat exchanger serves as a condenser, the refrigerant outlet of the heat source unit side heat exchanger Side, the refrigerant is circulated only to the second connection pipe side, the refrigerant is circulated from the first connection pipe only to the four-way switching valve side, and the heat source side heat exchanger serves as an evaporator. In mode operation, the first
Flow path switching device that allows the refrigerant to flow only from the connection pipe to the refrigerant inflow side of the heat source side heat exchanger, and allows the refrigerant to flow only from the four-way switching valve to the second connection pipe side; and the first branch. Section, the second branch portion, the gas-liquid separator, the second flow rate control device, the third flow rate control device, the fourth flow rate control device, the first bypass pipe, and the second A repeater having a bypass pipe of No. 3 and interposed between the heat source unit and the plurality of indoor units, and in the second connection pipe when switching from the heating mode operation to the cooling mode operation Alternatively, an air conditioner characterized by comprising a refrigerant replacement means for replacing the inside of the gas-liquid separation device with at least a gas-liquid two-phase refrigerant from the gas refrigerant. 2. A heat source unit including a compressor, a four-way switching valve, a heat source unit side heat exchanger, an accumulator, and the like, and a plurality of indoor units including an indoor side heat exchanger, a first flow rate control unit, and the like. And first and second connection pipes that connect the heat source unit and the plurality of indoor units in parallel, one side of the indoor heat exchanger of the plurality of indoor units, and the first connection pipe A first electromagnetic on-off valve provided in the middle of a pipe connecting to, a first side of the indoor heat exchanger of the plurality of indoor units and the second
Second solenoid on-off valve provided in the middle of a pipe connecting the above-mentioned connection pipe and a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units to the first connection pipe A first branch portion formed of a third electromagnetic on-off valve connected in parallel with the first electromagnetic on-off valve provided in the middle of
A second branch portion that connects the other side of the indoor heat exchanger of the plurality of indoor units to the second connection pipe via the first flow rate control device, and the second connection pipe. And a gas-liquid separator for separating a gas refrigerant and a liquid refrigerant, provided in the middle of the second connecting pipe between the lower portion of the gas-liquid separator and the second branch portion. A first flow rate control device, a first flow rate control device that is provided by connecting the second branch portion and the first connection pipe to each other, and has a third flow rate control device.
Bypass pipe, a second bypass pipe provided by connecting the second branch portion and the first connection pipe, and having a fourth flow rate control device, the first connection pipe, and the second bypass pipe.
In the cooling mode operation in which the bypass circuit having the fourth electromagnetic on-off valve provided by bypass connection with the connection pipe of No. 1 and the heat source unit side heat exchanger serves as a condenser, the refrigerant outlet of the heat source unit side heat exchanger Side, the refrigerant is circulated only to the second connection pipe side, the refrigerant is circulated from the first connection pipe only to the four-way switching valve side, and the heat source side heat exchanger serves as an evaporator. In mode operation, the first
Flow path switching device that allows the refrigerant to flow only from the connection pipe to the refrigerant inflow side of the heat source side heat exchanger, and allows the refrigerant to flow only from the four-way switching valve to the second connection pipe side; and the first branch. Section, the second branch portion, the gas-liquid separator, the second flow rate control device, the third flow rate control device, the fourth flow rate control device, the first bypass pipe, and the second A repeater having a bypass pipe between the heat source unit and the plurality of indoor units, and the fourth of the bypass circuit when switching from the heating mode operation to the cooling mode operation. And a first control means for controlling the solenoid valve to open so as to replace at least the gas-liquid two-phase refrigerant in the second connection pipe or in the gas-liquid separation device. Air conditioner. 3. A heat source unit including a compressor, a four-way switching valve, a heat source unit side heat exchanger, an accumulator, etc., and a plurality of indoor units including an indoor side heat exchanger, a first flow control device, etc. And first and second connection pipes that connect the heat source unit and the plurality of indoor units in parallel, one side of the indoor heat exchanger of the plurality of indoor units, and the first connection pipe A first electromagnetic on-off valve provided in the middle of a pipe connecting to, a first side of the indoor heat exchanger of the plurality of indoor units and the second
Second solenoid on-off valve provided in the middle of a pipe connecting the above-mentioned connection pipe and a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units to the first connection pipe A first branch portion formed of a third electromagnetic on-off valve connected in parallel with the first electromagnetic on-off valve provided in the middle of
A second branch portion that connects the other side of the indoor heat exchanger of the plurality of indoor units to the second connection pipe via the first flow rate control device, and the second connection pipe. And a gas-liquid separator for separating a gas refrigerant and a liquid refrigerant, provided in the middle of the second connecting pipe between the lower portion of the gas-liquid separator and the second branch portion. A first flow rate control device, a first flow rate control device that is provided by connecting the second branch portion and the first connection pipe to each other, and has a third flow rate control device.
Bypass pipe, a second bypass pipe provided by connecting the second branch portion and the first connection pipe, and having a fourth flow rate control device, the first connection pipe, and the second bypass pipe.
In the cooling mode operation in which the bypass circuit having the fourth electromagnetic on-off valve provided by bypass connection with the connection pipe of No. 1 and the heat source unit side heat exchanger serves as a condenser, the refrigerant outlet of the heat source unit side heat exchanger Side, the refrigerant is circulated only to the second connection pipe side, the refrigerant is circulated from the first connection pipe only to the four-way switching valve side, and the heat source side heat exchanger serves as an evaporator. In mode operation, the first
Flow path switching device that allows the refrigerant to flow only from the connection pipe to the refrigerant inflow side of the heat source side heat exchanger, and allows the refrigerant to flow only from the four-way switching valve to the second connection pipe side; and the first branch. Section, the second branch portion, the gas-liquid separator, the second flow rate control device, the third flow rate control device, the fourth flow rate control device, the first bypass pipe, and the second A repeater having a bypass pipe between the heat source unit and the plurality of indoor units, and the second unit in the repeater when switching from the heating mode operation to the cooling mode operation. Second control for opening the flow rate control device and other at least one flow rate control device to control the inside of the second connecting pipe or the inside of the gas-liquid separator to replace at least the gas-liquid two-phase refrigerant To be equipped with means Air conditioning apparatus and butterflies. 4. A heat source unit comprising a compressor, a four-way switching valve, a heat source unit side heat exchanger, an accumulator, etc., and a plurality of indoor units comprising an indoor side heat exchanger, a first flow rate control device, etc. And first and second connection pipes that connect the heat source unit and the plurality of indoor units in parallel, one side of the indoor heat exchanger of the plurality of indoor units, and the first connection pipe A first electromagnetic on-off valve provided in the middle of a pipe connecting to, a first side of the indoor heat exchanger of the plurality of indoor units and the second
Second solenoid on-off valve provided in the middle of a pipe connecting the above-mentioned connection pipe and a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units to the first connection pipe A first branch portion formed of a third electromagnetic on-off valve connected in parallel with the first electromagnetic on-off valve provided in the middle of
A second branch portion that connects the other side of the indoor heat exchanger of the plurality of indoor units to the second connection pipe via the first flow rate control device, and the second connection pipe. And a gas-liquid separator for separating a gas refrigerant and a liquid refrigerant, provided in the middle of the second connecting pipe between the lower portion of the gas-liquid separator and the second branch portion. A first flow rate control device, a first flow rate control device that is provided by connecting the second branch portion and the first connection pipe to each other, and has a third flow rate control device.
Bypass pipe, a second bypass pipe provided by connecting the second branch portion and the first connection pipe, and having a fourth flow rate control device, the first connection pipe, and the second bypass pipe.
In the cooling mode operation in which the bypass circuit having the fourth electromagnetic on-off valve provided by bypass connection with the connection pipe of No. 1 and the heat source unit side heat exchanger serves as a condenser, the refrigerant outlet of the heat source unit side heat exchanger Side, the refrigerant is circulated only to the second connection pipe side, the refrigerant is circulated from the first connection pipe only to the four-way switching valve side, and the heat source side heat exchanger serves as an evaporator. In mode operation, the first
Flow path switching device that allows the refrigerant to flow only from the connection pipe to the refrigerant inflow side of the heat source side heat exchanger, and allows the refrigerant to flow only from the four-way switching valve to the second connection pipe side; and the first branch. Section, the second branch portion, the gas-liquid separator, the second flow rate control device, the third flow rate control device, the fourth flow rate control device, the first bypass pipe, and the second A repeater having a bypass pipe between the heat source unit and the plurality of indoor units, and the first solenoid valve when switching from the heating mode operation to the cooling mode operation. And a third control means for controlling the second electromagnetic on-off valve to open to replace at least the gas-liquid two-phase refrigerant in the second connection pipe or in the gas-liquid separation device. An air conditioner characterized by. 5. A heat source unit comprising a compressor, a four-way switching valve, a heat source unit side heat exchanger, an accumulator and the like, and a plurality of indoor units comprising an indoor side heat exchanger, a first flow control device and the like. And first and second connection pipes that connect the heat source unit and the plurality of indoor units in parallel, one side of the indoor heat exchanger of the plurality of indoor units, and the first connection pipe A first electromagnetic on-off valve provided in the middle of a pipe connecting to, a first side of the indoor heat exchanger of the plurality of indoor units and the second
Second solenoid on-off valve provided in the middle of a pipe connecting the above-mentioned connection pipe and a pipe connecting one side of the indoor heat exchanger of the plurality of indoor units to the first connection pipe A first branch portion that is provided in the middle of the first solenoid opening / closing valve and is connected in parallel with the first electromagnetic opening / closing valve and has a smaller opening diameter than the first electromagnetic opening / closing valve; A second branch portion that connects the other side of the indoor heat exchanger of the indoor unit of the table to the second connection pipe via the first flow rate control device, and the middle of the second connection pipe. A gas-liquid separating device for separating a gas refrigerant and a liquid refrigerant, and a second connecting pipe provided between the lower portion of the gas-liquid separating device and the second branch portion. Of the flow control device, the second branch portion and the first connecting pipe are connected to each other. A first bypass pipe having a third flow control device; a second bypass pipe having a fourth flow control device, which is provided by connecting the second branch portion and the first connection pipe; During a cooling mode operation in which the first connection pipe and the second connection pipe are bypass-connected and provided with a fourth electromagnetic on-off valve, and the heat source side heat exchanger serves as a condenser, The refrigerant is circulated from the refrigerant outlet side of the heat source unit side heat exchanger only to the second connection pipe side, and the refrigerant is circulated only from the first connection pipe to the four-way switching valve side, and the heat source unit During the heating mode operation in which the side heat exchanger serves as an evaporator, the refrigerant is circulated from the first connection pipe only to the refrigerant inflow side of the heat source side heat exchanger, and the four-way switching valve is connected to the second connection pipe side. Flow that only allows the refrigerant to flow A switching device, the first branch portion, the second branch portion, the gas-liquid separator,
The heat source device and the plurality of units, each of which has the second flow control device, the third flow control device, the fourth flow control device, the first bypass pipe, and the second bypass pipe. When the switching from the heating mode operation to the cooling mode operation is performed, the relay device interposed between the indoor unit and the indoor unit is opened to open the second electromagnetic on-off valve and the third electromagnetic on-off valve, and the second electromagnetic on-off valve is opened. And a fourth control means for controlling the inside of the connection pipe or the inside of the gas-liquid separator to replace at least the gas-liquid two-phase refrigerant.