JP2616524B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A conventional example will be described below. FIG. 6 is an overall configuration diagram mainly showing a refrigerant system of a conventional air conditioner. FIGS. 7, 8, and 9 show operating states during the cooling / heating operation in the conventional example of FIG. 6, FIG. 7 is an operating state diagram of only the cooling or heating operation, and FIGS. FIG. 8 shows the operation of the operation, in which FIG. 8 shows the main heating operation (when the total capacity of the indoor units performing the heating operation is larger than the total capacity of the indoor units performing the cooling operation), and FIG. 9 shows the main cooling operation (the cooling operation is performed). (When the total capacity of the indoor units to be heated is larger than the total capacity of the indoor units to be heated). In this conventional example, a case where three indoor units are connected to one heat source unit will be described, but the same applies to a case where two or more indoor units are connected.

In FIG. 6, A is a heat source unit, and B, C, and D are indoor units connected in parallel to each other as described later, and have the same configuration. E is a repeater including a first branch, a second flow controller, a second branch, a gas-liquid separator, and first and second heat exchangers, as described later. 1 is a compressor, 2 is a four-way switching valve for switching the refrigerant flow direction of the heat source device, 3 is a heat source device side heat exchanger, 4 is an accumulator, and is connected to the above devices 1 to 3 to constitute a heat source device A. 5 is the indoor heat exchanger of each of the indoor units B, C and D, 6 is a thick first connection pipe connecting the four-way switching valve 2 and the relay unit E, and 6b, 6c and 6d are the indoor units B and C, respectively. ,
D connects the indoor-side heat exchanger 5 to the repeater E, and the first connection pipe 7 on the indoor unit corresponding to the first connection pipe 6 connects the heat-source-unit-side heat exchanger 3 to the repeater E. Second connection pipes 7b, 7c, and 7d, which are thinner than the first connection pipe 6, connect the indoor heat exchangers 5 of the indoor units B, C, and D to the repeater E, respectively, and provide a second connection pipe. 7, a second connection pipe on the indoor unit side corresponding to 7, 8 is a first connection pipe 6b, 6c on the indoor unit side,
6d is a valve device that is switchably connected to the first connection pipe 6 or the second connection pipe 7 side, and a three-way switching valve is used. Reference numeral 9 denotes a first flow rate control device which is connected in proximity to the indoor heat exchanger 5 and controlled by the degree of superheat on the outlet side of the indoor heat exchanger 5 during cooling and by the degree of supercooling during heating,
It is connected to the second connection pipes 7b, 7c, 7d on the indoor unit side.

Reference numeral 10 denotes first connection pipes 6b, 6 on the indoor unit side.
c, 6d and a first three-way switching valve 8 switchably connected to the first connection pipe 6 or the second connection pipe 7.
And 11 are second connection pipes 7b and 7 on the indoor unit side.
c, 7d, and a second branch portion 12 composed of a meeting portion thereof, a gas-liquid separation device provided in the middle of the second connection pipe 7,
The gas phase is connected to each first port 8 a of the three-way switching valve 8, and the liquid phase is connected to the second branch 11. Reference numeral 13 denotes an openable and closable second flow rate control device connected between the gas-liquid separation device 12 and the second branch portion 11, and reference numeral 14 denotes a bypass pipe connecting the second branch portion 11 and the first connection pipe 6. , 15 are third members provided in the middle of the bypass pipe 14.
The flow control devices 16b, 16c, and 16d are provided downstream of the third flow control device 15 in the bypass pipe 14, and the second connection pipe 7 on the indoor unit side in the second branch 11
b, 7c, and 7d, a third heat exchange unit that exchanges heat with the third flow control device 15 of the bypass pipe 14 and the third heat exchange units 16b, 16c, and 16d, respectively.
d, a second heat exchanging unit for exchanging heat with the junction of the second connection pipes 7b, 7c, 7d on the indoor unit side in the second branching unit 11, and 19 is a bypass. Piping 1
4, heat exchange is performed between pipes provided downstream of the third flow control device 15 and downstream of the second heat exchange unit 16a and connecting the gas-liquid separation device 12 and the second flow control device 13. A first heat exchange section, a fourth open / closeable fourth flow control device connected between the second branch section and the first connection pipe;
Reference numeral 32 denotes a third check valve provided between the heat source unit side heat exchanger 3 and the second connection pipe 7, and refrigerant flows only from the heat source unit side heat exchanger 3 to the second connection pipe 7. Tolerate.

Reference numeral 33 denotes a fourth check valve provided between the four-way switching valve 2 of the heat source unit A and the first connection pipe 6, and a first check valve 33 is provided.
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
And a fifth check valve provided between the four-way switching valve 2
To the second connection pipe 7 only. 35
Is a sixth check valve provided between the heat source unit side heat exchanger 3 and the first connection pipe 6, and allows the refrigerant to flow only from the first connection pipe 6 to the heat source unit side heat exchanger 3. Allow. The third non-return valve 32 to the sixth non-return valve 35 are used by the flow path switching valve device 40.
Is configured. Reference numeral 23 denotes a first temperature detector attached to a pipe connecting the second flow control device 13 and the first heat exchange unit 19, and reference numeral 25 denotes a first temperature detector attached to the same pipe as the first temperature detector 23. The pressure detector 26 is a second pressure detector attached to the second branch portion 11.

A conventional example having such a configuration will be described. First, the case of only the cooling operation will be described with reference to FIG. That is, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 is supplied to the four-way switching valve 2 as indicated by a solid arrow in FIG.
, The heat is exchanged in the heat source device side heat exchanger 3 and condensed, and then the third check valve 32, the second connection pipe 7, the gas-liquid separator 12, and the second flow controller 13 are arranged in this order. Yes, second
, The second connection pipes 7b, 7c on the indoor unit side,
The refrigerant flowing into each of the indoor units B, C, and D through 7d is controlled by the degree of superheat at the outlet of each of the indoor heat exchangers 5.
Is reduced to a low pressure by the flow control device 9, and heat exchanges with the indoor air in the indoor heat exchanger 5 to evaporate and gasify, thereby cooling the room. The refrigerant in the gaseous state passes through the first connection pipes 6b, 6c, 6d, the three-way switching valve 8, and the first branch portion 10 on the indoor unit side, and passes through the first connection pipe 6, the fourth connection pipe.
A circulation cycle is drawn through the check valve 33, the four-way switching valve 2, and the accumulator 4 to the compressor 1 to perform the cooling operation. In this case, the three-way switching valve 8 is connected to each of the first ports 8.
a is closed, and the second port 8b and the third port 8c are open.

At this time, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, the refrigerant necessarily flows to the third check valve 32 and the fourth check valve 33. At the time of this cycle, a part of the refrigerant that has passed through the second flow control device 13 enters the bypass pipe 14 and is reduced to a low pressure by the third flow control device 15, so that the third heat exchange unit 16b, 16c, 1
6d between the second connection pipes 7b, 7c, 7d on the indoor unit side, and the second heat exchange section 16a at the second branch section 11
Heat exchange between the second connection pipes 7b, 7c, 7d on the side of each indoor unit and the refrigerant flowing into the second flow control device 13 in the first heat exchange unit 19 The evaporated refrigerant enters the first connection pipe 6 and the fourth check valve 33,
It is sucked into the compressor 1 via the four-way switching valve 2 and the accumulator 4. On the other hand, the first, second, and third heat exchange units 19,
The refrigerant in the second branch portion 11, which has been subjected to heat exchange at 16a, 16b, 16c, and 16d and cooled and has a sufficient degree of subcooling, flows into the indoor units B, C, and D to be cooled.

Next, the case of only the heating operation will be described with reference to FIG. That is, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2 as shown by the dashed arrow in FIG. 7, the fifth check valve 34, the second connection pipe 7,
The refrigerant flowing into the indoor units B, C, and D through the gas-liquid separator 12, the first branch portion 10, the three-way switching valve 8, the first connection pipes 6b, 6c, and 6d on the indoor unit side, Heat exchanges with indoor air to condense and liquefy and heat the room. The refrigerant in the liquid state passes through the first flow control device 9 controlled by the degree of supercooling at the outlet of each indoor heat exchanger 5, and
The second connection pipes 7b, 7c, and 7d on the indoor unit side flow into the second branch portion 11 and merge there, and further pass through the fourth flow control device 17, where the first flow control device 9 or the The pressure is reduced to a low-pressure gas-liquid two-phase state in one of the flow control device 17 and the third flow control device 14. Then, the refrigerant decompressed to a low pressure passes through the first connection pipe 6 and passes through the sixth connection pipe.
The refrigerant that has flowed into the heat source unit side heat exchanger 3 and exchanged heat to evaporate into a gaseous state through the four-way switching valve 2 and the accumulator 4 constitutes a circulation cycle drawn into the compressor 1. Then, perform the heating operation. At this time, the three-way switching valve 8 has the second port 8b closed, the first port 8a and the third port 8c.
Is open. At this time, the first connection pipe 6 has a low pressure,
Since the second connection pipe 7 has a high pressure, the fifth check valve 3 is inevitably required.
4. The refrigerant flows to the sixth check valve 35.

Referring to FIG. 8, a description will be given of a case in which heating is mainly performed in simultaneous operation of cooling and heating. Here, the case where two indoor units B and C are going to heat and one indoor unit D is going to cool will be described. That is, as indicated by solid arrows in FIG. 8, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, the fifth check valve 34, and the second connection pipe 7, and passes through the relay E To the first branch 10, the three-way switching valve 8 connected to the indoor units B and C, and the first connection pipes 6 b and 6 c on the indoor unit side in this order. The refrigerant flowing into the indoor units B and C to be heated exchanges heat with the indoor air in the indoor heat exchanger 5 to be condensed and liquefied, thereby heating the room. The refrigerant in the liquid state is controlled by the degree of supercooling at the outlet of the indoor heat exchanger 5, is slightly reduced in pressure through the first flow control device 9 which is almost fully opened, and is intermediate between high pressure and low pressure. Pressure (intermediate pressure), and from the second connection pipes 7b and 7c on the indoor unit side to the second branch 1
Flow into 1. Then, the second connection pipe 7d on the indoor unit side
To the indoor unit D which is about to be cooled, and after being decompressed by the first flow rate control device 9 controlled by the degree of superheat at the outlet of the indoor side heat exchanger 5, it enters the indoor side heat exchanger 5 and exchanges heat. After evaporating to a gas state, the room is cooled, and flows into the first connection pipe 6 via the three-way switching valve 8 connected to the indoor unit D.

On the other hand, the other refrigerant is supplied to the second branch portion 11, the second branch portion.
Through an openable and closable fourth flow control device 17 controlled to make the difference between the high pressure of the connection pipe 7 and the intermediate pressure of the second branch portion 11 constant, and through the indoor unit D to be cooled. Refrigerant flowing into the thick first connection pipe 6 and flowing into the sixth check valve 38 and the heat source device side heat exchanger 3 to exchange heat and evaporate into a gaseous state. A circulation cycle is drawn into the compressor 1 via the switching valve 2 and the accumulator 4, and the heating-main operation is performed. At this time, the pressure difference between the evaporation pressure of the indoor-side heat exchanger 5 of the indoor unit D to be cooled and the evaporation pressure of the heat-source-unit-side heat exchanger 3 is reduced due to switching to the thick first connection pipe 6. At this time, the three-way switching valve 8 connected to the indoor units B and C
8b is closed, and the first port 8a and the third port 8c are open. In the three-way switching valve 8 connected to the indoor unit D, the second port 8b and the third port 8c are open, and the first port 8a is closed.

At this time, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, the refrigerant necessarily flows to the fifth check valve 34 and the sixth check valve 35. In this cycle, a part of the liquid refrigerant is supplied to the second connection pipe 7 on each indoor unit side.
b, 7c, 7d enter the bypass pipe 14 from the junction,
The pressure is reduced to a low pressure by the third flow control device 15, and the third heat exchange units 16b, 16c, 16d communicate with the second connection pipes 7b, 7c, 7d on the indoor unit side, and A second flow control device is provided between the heat exchange unit 16a and the associated portion of the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch unit 11, and further, a second flow control device is provided at the first heat exchange unit 19. The refrigerant evaporated by performing heat exchange with the refrigerant flowing into the first connection pipe 6
Through the sixth check valve 35, the heat source unit side heat exchanger 3
And heat exchange to evaporate to a gaseous state. Then, the refrigerant is sucked into the compressor 1 via the four-way switching valve 2 and the accumulator 4. On the other hand, the second branch portion 1 which has been cooled by being exchanged heat in the first, second and third heat exchange portions 19, 16a, 16b, 16c and 16d and having a sufficient degree of subcooling has been provided.
The refrigerant No. 1 flows into the indoor unit D to be cooled.

Referring to FIG. 9, a description will be given of a case where cooling is mainly performed in simultaneous cooling and heating operation. Here, indoor units B and C
A case will be described in which two units are going to be cooled and one indoor unit D is going to heat. That is, as shown by the experimental arrow in FIG. 9, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2 and exchanges an arbitrary amount of heat in the heat source device side heat exchanger 3 to form a gas-liquid two-phase. It becomes high temperature and high pressure gas and the third check valve 3
2. From the second connection pipe 7, the gas-liquid separation device 1 of the repeater E
Sent to 2. Here, the gaseous refrigerant is separated into a gaseous refrigerant and a liquid refrigerant, and the separated gaseous refrigerant is going to be heated in the order of the first branch portion 10, the three-way switching valve 8, and the first connection pipe 6d on the indoor unit side. It flows into the indoor unit D, exchanges heat with the indoor air in the indoor heat exchanger 5 to condense and liquefy, and heats the room. Further, the pressure is slightly reduced through the first flow control device 9 which is controlled by the degree of supercooling at the outlet of the indoor side heat exchanger 5 and is almost fully open, and becomes an intermediate pressure between the high pressure and the low pressure (intermediate pressure). Flows into the branching portion 11. On the other hand, the remaining liquid refrigerant flows into the second branch portion 11 through the second flow control device 13 which is controlled so as to keep the difference between the high pressure and the intermediate pressure, and the indoor unit D which is going to heat is cooled. Merges with the passed refrigerant.

Then, the air flows into the indoor units B and C through the second branch portion 11 and the second connection pipes 7b and 7c on the indoor unit side. The refrigerant is reduced to a low pressure by the first flow control device 9 controlled by the degree of superheat at the outlet of the indoor heat exchanger 5 of the indoor units B and C, and the indoor heat exchanger 5 is connected to the indoor air. It is evaporated and gasified by heat exchange to cool the room.
Then, the refrigerant in the gas state is supplied to the first unit on the indoor unit side.
Connection pipes 6b and 6c, three-way switching valve 8 connected to indoor units B and C, first branch portion 10, first connection pipe 6, fourth connection pipe
Of the compressor 1 through the check valve 33, the four-way switching valve 2, and the accumulator 4 to perform the cooling-main operation. At this time, the first port 8a of the three-way switching valve 8 connected to the indoor units B and C is closed, and the second port 8b and the third port 8c are open. Further, the three-way switching valve 8 connected to the indoor unit D has the first port 8a and the third port 8c open,
The second port 8b is closed.

At this time, the first connection pipe 6 has a low pressure,
The third check valve 32 is inevitably because the connection pipe 7 has a high pressure.
The refrigerant flows to the fourth check valve 33. In this cycle, a part of the liquid refrigerant is supplied to the second connection pipe 7 on each indoor unit side.
b, 7c, 7d enter the bypass pipe 14 from the junction,
The pressure is reduced to a low pressure by the third flow control device 15, and the third heat exchange units 16b, 16c, 16d communicate with the second connection pipes 7b, 7c, 7d on the indoor unit side, and A second flow control device is provided between the heat exchange unit 16a and the associated portion of the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch unit 11, and further, a second flow control device is provided at the first heat exchange unit 19. The refrigerant evaporated by performing heat exchange with the refrigerant flowing into the first connection pipe 6
And is sucked into the compressor 1 through the fourth check valve 33, the four-way switching valve 2, and the accumulator 4. On the other hand, the first, second, and third heat exchange units 19, 16a, 16b, 16c,
The refrigerant in the second branch portion 11, which has been cooled by heat exchange at 16d and has a sufficient degree of supercooling, flows into the indoor units B and C to be cooled.

[0015]

In the conventional air conditioner as described above, when a plurality of indoor units are connected to a heat source unit, the connection is performed through one relay unit. When the range is widened, the connection pipe length from the repeater to the indoor unit becomes longer, and thus the total connection pipe length becomes longer, which causes a problem that the workability is deteriorated. Even if the number of connected indoor units increases, the number of connected indoor units increases because the number of connected indoor units increases because the number of connected indoor units increases. There was a problem of doing.

The present invention has been made in order to solve the above-mentioned problems, and even when a plurality of indoor units are installed and connected to a single heat source unit over a wide range,
It is an object of the present invention to obtain an air conditioner having good connection pipe workability and repeater installation property.

[0017]

SUMMARY OF THE INVENTION An air conditioner according to the present invention comprises a single heat source unit including a compressor, a switching valve, a heat source side heat exchanger, etc., and a plurality of indoor units each having an indoor side heat exchanger. And the indoor unit is connected via the first and second connection pipes, and is provided between the first and second connection pipes, respectively, by switching the direction of the flowing refrigerant,
During operation, at all times, the first connection pipe interposed between the heat source unit and the indoor unit has a low pressure, and the second connection pipe has a high pressure. A plurality of indoor unit constituent units including indoor units and, for each indoor unit constituent unit, one of the indoor side heat exchangers is switched to a first connection pipe or a second connection pipe via a gas-liquid separation device. A first branch having a valve device to be connected, and the other of the indoor heat exchangers for each indoor unit constituent unit connected to a second connection pipe via a first flow control device. And a second branch portion provided in the second connection pipe and connected between the gas-liquid separation device and the second branch portion for each indoor unit constituent unit.
A second flow control device that branches from the second branch portion corresponding to each of the indoor units constituting units, a bypass circuit through the bypass flow control device connected to said first connecting pipe,
Said first, second branch portion corresponding to each indoor unit configuration unit,
Gas-liquid separator, a second flow controller, and a plurality of repeater that incorporates respectively a flow control device for及beauty bypass, each relay
From the gas-liquid separator of the machine to the valve device at the first branch
Gas connection piping that communicates between the
Between the pipes from the flow control device to the second flow control device
And a liquid connecting pipe communicating therewith .

[0018]

In the air conditioner constructed as described above, when a plurality of indoor units are connected to the heat source unit, the operation is performed via a plurality of repeaters, so even if the installation range of the connected indoor units is wide. The pipe length from the repeater to the indoor unit can be shortened, so that the total connection pipe length is shortened, and the workability can be improved. Further, even if the number of indoor units to be connected is increased, since the connection is made to a plurality of repeaters, there is no need to increase the size of the repeaters, and the problem that the installability of the repeaters deteriorates can be solved. it can.

[0019]

【Example】

Embodiment 1 FIG. Hereinafter, embodiments of the present invention will be described.
FIG. 1 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to Embodiment 1 of the present invention. 2, 3, and 4
FIG. 2 shows an operation state of the air-conditioning apparatus shown in FIG. 1 during a cooling and heating operation, FIG. 2 shows an operation state of only the cooling or heating operation, and FIGS. 3 and 4 show an operation of the simultaneous cooling and heating operation. FIG. 3 shows a case where the total capacity of the indoor units that are going to perform the heating operation is larger than the total capacity of the indoor units that are going to perform the cooling operation. FIG. 11 is an operation state diagram showing a case where the heating operation is larger than the total capacity of the indoor units to be heated. FIG. 5 is an overall configuration diagram mainly showing a refrigerant system of an air conditioner according to another embodiment of the present invention. In this embodiment, a case where six indoor units and two relay units are connected to one heat source unit will be described, but the same applies to a case where two or more indoor units and two or more relay units are connected. is there.

In FIGS. 1 to 5, AE and 1 to 40 are the same as those of the above-mentioned conventional apparatus. In this embodiment, three indoor units ( six units) and three indoor units (hereinafter referred to as structural units)
) , And 60 and 70 are structural units each including indoor units B, C, D, and F, G, and H. E and I are a first branch unit 10, a second branch unit 11, and a second flow control unit corresponding to the structural units 60 and 70, respectively.
Control apparatus 13, the third as a bypass flow control device, a fourth flow rate control equipment 1 5,17, first, second, third heat exchanger 19,16a, 16b, 16c, 16d, and by
This is a repeater incorporating a pass circuit (by-pass pipe 14 in this embodiment ) and the like, interposed between the indoor units B, C, D and F, G, H and the heat source unit A, and connected in parallel with each other. It is a thing.

The first connection pipe 6 for connecting the heat source unit A to the repeater E and the repeater I is divided into two parts on the way, and each of the first branch portions 10 of the repeater E and the repeater I is connected.
Connected to Further, the heat source device A, the relay device E, and the relay device I
Are connected to the gas-liquid separators 12 of the repeater E and the repeater I, respectively. 6f, 6g, and 6h connect the indoor-side heat exchangers 5 of the indoor units F, G, and H to the relay unit I, respectively, and connect the first connection pipe on the indoor unit side corresponding to the first connection pipe 6, 7f, Reference numerals 7g and 7h denote second connection pipes on the indoor unit side corresponding to the second connection pipes 7, which connect the indoor side heat exchangers 5 of the indoor units F, G and H to the relay unit I, respectively. 50
Are pipes extending from the second connection pipe 7 to the valve device 8 of the first branch part built in the repeater E, and a first branch part built in the repeater I from the second connection pipe 7. A gas connection pipe 51 that communicates with a pipe reaching the valve device 8 is provided with a pipe 51 extending from the first flow control device 9 of the repeater E to the second flow control device 13 and a first pipe 51 of the repeater I. This is a liquid connection pipe that communicates with a pipe from the flow control device 9 to the second flow control device 13.

An embodiment of the present invention configured as described above will be described. First, the case of only the cooling operation will be described with reference to FIG. That is, as shown by a solid line arrow in FIG. 2, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the switching valve 2 and is condensed by exchanging heat with the heat source device side heat exchanger 3. Through the third check valve 32 and the second connection pipe 7,
2 of the refrigerant flowing into the repeater E and the refrigerant flowing into the repeater I
It is divided. The two divided refrigerants flow into the second branch portion 11 in the order of the gas-liquid separators 12 and the second flow control devices 13 of the repeaters E and I, respectively. Second
Flows into the second connection pipe 7b, 7c, 7d on the indoor unit side or the second connection pipe 7 on the indoor unit side.
f, 7g, and 7h, and flows into each of the indoor units B, C, and D or the indoor units F, G, and H, and is controlled by the degree of superheat at the outlet of each indoor-side heat exchanger 5. The pressure is reduced to a low pressure by 9 and heat exchanges with indoor air in the indoor heat exchanger 5 to evaporate and gasify, thereby cooling the room. The refrigerant in the gaseous state is supplied to the first connection pipes 6b, 6b on the indoor unit side.
c, 6d or the first connection pipe 6f, 6g, 6 on the indoor unit side
h, the valve device (in this embodiment, the three-way switching valve 8), the first connection pipe 6, the first connection pipe 6, the fourth check valve 3,
3. A circulation cycle is drawn into the compressor 1 via the switching valve 2 and the accumulator 4 to perform a cooling operation. At this time, the first port 8a of the three-way switching valve 8 is closed, and the second port 8b and the third port 8c are open.

At this time, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, the refrigerant necessarily flows to the third check valve 32 and the fourth check valve 33. At the time of this cycle, a part of the refrigerant that has passed through the second flow control device 13 enters the bypass pipe 14 and is reduced to a low pressure by the third flow control device 15, so that the third heat exchange unit 16b, 16c, 1
6d between the second connection pipes 7b, 7c, 7d on the indoor unit side or the second connection pipes 7f, 7g, 7h on the indoor unit side, and the second heat exchange unit 16a the second connection pipe 7b of the indoor-side branching portion 11, 7c, 7d and the indoor unit side second connection pipes 7f, 7 g, with the association of 7h, further first heat exchanging portion In 19, the second flow control device 13
The refrigerant evaporated by performing heat exchange with the refrigerant flowing into the
It enters the first connection pipe 6 and is sucked into the compressor 1 through the fourth check valve 33 , the switching valve 2, and the accumulator 4. On the other hand, the first, second and third heat exchange units 19, 16a, 1
The refrigerant in the second branch portion 11, which has been subjected to heat exchange in 6b, 16c, and 16d and cooled to have a sufficient degree of supercooling, flows into the indoor units B, C, D, F, G, and H to be cooled. .

Next, the case of only the heating operation will be described with reference to FIG. That is, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the switching valve 2, passes through the fifth check valve 34, the second connection pipe 7, and passes through the relay E And a refrigerant flowing into the relay device I. The two divided refrigerants flow into the respective gas-liquid separators 12 and the first branch portion 10 of the repeaters E and I. The refrigerant flowing into the first branch 10 is
Three-way switching valve 8, indoor unit-side first connection pipes 6b, 6c,
6d or the first connection pipe 6f, 6g, 6h on the indoor unit side, flows into each of the indoor units B, C, D or the indoor units F, G, H, exchanges heat with indoor air and condenses and liquefies, Heat the room. The refrigerant in the liquid state passes through the first flow control device 9 controlled by the degree of supercooling at the outlet of each indoor heat exchanger 5, and passes through the second connection pipes 7b and 7 on the indoor unit side.
c, 7d or the second connection pipes 7f, 7g, 7 on the indoor unit side
h flows into the second branch portion 11 and merges therewith, and further passes through the fourth flow control device 17 where the first flow control device 9
Or, the fourth flow control device 17 and the third flow control device 15
The pressure is reduced to a low-pressure gas-liquid two-phase state in one of the two.
The refrigerant depressurized to a low pressure is supplied to the first connection pipe 6
The refrigerant which flows into the sixth check valve 35 and the heat source unit side heat exchanger 3 and exchanges heat to evaporate into a gaseous state is sucked into the compressor 1 via the switching valve 2 and the accumulator 4. A circulation cycle is configured to perform heating operation. At this time, the three-way switching valve 8 has the second port 8b closed and the first port 8a and the third port 8c open. At this time, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure,
The refrigerant flows through the check valve 34 and the sixth check valve 35.

Referring to FIG. 3, a description will be given of a case where a heating is mainly performed in the simultaneous cooling and heating operation. Here, indoor units B, C,
A case will be described in which four units D and F are heating, and two indoor units G and H are trying to cool. That is, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 flows through the switching valve 2, the fifth check valve 34, and the second connection pipe 7 as shown by the solid line arrow in FIG. And the refrigerant flowing into the relay device I. The two divided refrigerants flow into the respective gas-liquid separators 12 and the first branch portion 10 of the repeaters E and I. The refrigerant flowing into the first branch portion 10 is supplied to the three-way switching valve 8 connected to the indoor units B, C, D and the indoor unit F, and the first connection pipes 6b, 6c, 6d on the indoor unit side.
And flows into the indoor units B, C, D, and F to be heated in the order of the first connection pipe 6f on the indoor unit side, and exchanges heat with the indoor air in the indoor side heat exchanger 5 to condense and liquefy. Heat the room. The refrigerant in the liquid state is controlled by the degree of supercooling at the outlet of the indoor heat exchanger 5, is slightly reduced in pressure through the first flow control device 9 which is almost fully opened, and is intermediate between high pressure and low pressure. Pressure (intermediate pressure).
Flows into the second branch portion 11 from the connection pipes 7b, 7c, and 7d and the second connection pipe 7f on the indoor unit side. The flow rate of the refrigerant flowing into the indoor units B, C, D, and F is determined according to the magnitude of the heating load of the indoor units B, C, D, and F to be heated. Also, the flow rates of the gas refrigerant supplied from the heat source unit A to the relay units E and I, and the indoor units B, C, and D that are about to heat from the first branch portions 10 of the relay units E and I, respectively. , F are always the same.
Therefore, in the repeater E, the gas refrigerant flow supplied from the gas-liquid separator 12 to the first branch 10 and the gas refrigerant flow supplied to the indoor units B, C, and D to be heated from the first branch And the flow rate of the gas refrigerant supplied from the gas-liquid separation device 12 to the first branch 10 and the flow rate of the gas refrigerant supplied from the first branch to the indoor unit F to be heated in the relay unit I. In order to correct the imbalance, the gas connection pipe 5
0, the gas refrigerant is supplied from the repeater E to the repeater I or from the repeater I to the repeater E.

The flow of the refrigerant to the indoor units G and H to be cooled flows from the second branch portion 11 of the repeater I through the second connection pipes 7g and 7h on the indoor unit side, and passes through the indoor heat exchanger. 5
First flow control device 9 controlled by the degree of superheat at the outlet
After being decompressed by the air conditioner, it enters the indoor side heat exchanger 5 and exchanges heat to evaporate to a gaseous state to cool the room.
Flows into the first connection pipe 6 through the three-way switching valve 8 connected to the first connection pipe 6. The flow rate of the refrigerant flowing into the indoor units G and H is determined according to the magnitude of the cooling load of the indoor units G and H to be cooled. Therefore, the flow rate of the refrigerant flowing into the indoor units G and H from the second branch portion 11 of the repeater I is changed from the indoor unit F to the repeater I
When the flow rate is larger than the flow rate of the refrigerant flowing into the second branch portion 11 of the relay device E,
Of the refrigerant flowing into the second branch 11 of the repeater I from the repeater E through the liquid connection pipe 51 to the second branch 11 of the repeater I from the indoor unit F. And flows into the indoor units G and H. On the other hand, indoor unit B,
The other refrigerant flowing into the second branch portion 11 of the repeater E from C and D is controlled so as to keep the difference between the high pressure of the second connection pipe 7 and the intermediate pressure of the second branch portion 11 constant. Through the openable and closable fourth flow control device 17 and the refrigerant that has passed through the indoor units G and H to be cooled, flows into the thick first connection pipe 6, and flows into the sixth check valve. via 35 flows into the heat source apparatus side heat exchanger 3, the refrigerant is evaporated to a gas state by heat exchange, the switching valve 2, the compressor via the accumulator 4 1
A circulation cycle that is drawn into the system is formed, and a heating-main operation is performed.

The flow rate of the refrigerant flowing into the indoor units G and H from the second branch portion 11 of the repeater I is changed from the indoor unit F to the repeater I
Is smaller than the flow rate of the refrigerant flowing into the second branch portion 11 of the relay device I, a part of the refrigerant flowing into the second branch portion 11 of the relay device I from the indoor unit F is changed to the second branch portion 11 of the relay device I. From the indoor unit F to the indoor units G and H,
The other refrigerant flowing into the branch portion 11 of the indoor units B, C, D
Along with the refrigerant that has flowed into the second branch of the repeater E, the openable and closable second is controlled so that the difference between the high pressure of the second connection pipe 7 and the intermediate pressure of the second branch 11 is constant. 4, the refrigerant that has passed through the indoor units G and H to be cooled, merges with the refrigerant, flows into the thick first connection pipe 6, and flows into the sixth check valve 35, the heat source unit side heat. The refrigerant that has flowed into the exchanger 3 and exchanged heat to evaporate into a gaseous state passes through the switching valve 2 and the accumulator 4 and is drawn into the compressor 1 to perform a heating-main operation.

At this time, the pressure difference between the evaporation pressure of the indoor side heat exchanger 5 of the indoor units G and H to be cooled and the evaporation pressure of the heat source unit side heat exchanger 3 is switched to the thick first connection pipe 6. To be smaller. At this time, the indoor units B, C,
The three-way switching valves 8 connected to D and F have respective second ports 8.
b is closed, and the first port 8a and the third port 8c are open. The three-way switching valve 8 connected to the indoor units G and H is
The port 8b and the third port 8c are open, and the first port 8a is closed. At this time, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, the refrigerant necessarily flows to the fifth check valve 34 and the sixth check valve 35.

Further, when this cycle, part of the liquid refrigerant second connection pipe 7b of the indoor unit side, 7c, the meeting part of 7d to the bypass pipe 14 of the relay unit E, or of the indoor unit side From the junction of the second connection pipes 7f, 7g, 7h, the repeater I
Into the bypass pipe 14. The refrigerant that has entered the bypass pipe 14 is decompressed to a low pressure by the third flow control device 15, and the second connection pipes 7b, 7c, 7d on the indoor unit side in the third heat exchange units 16b, 16c, 16d. Alternatively, between the second connection pipes 7f, 7g, and 7h on each indoor unit side, and the second heat exchange unit 16a, the second branch unit 11 on the second branch unit 11 side on each indoor unit side
Between the second connection pipes 7b, 7c, 7d or the associated sections of the second connection pipes 7f, 7g, 7h on the indoor unit side, and further into the second flow control device 13 at the first heat exchange section 19. The refrigerant that has undergone heat exchange with the refrigerant to be evaporated enters the first connection pipe 6, flows into the heat source unit side heat exchanger 3 via the sixth check valve 35, exchanges heat, and evaporates. It becomes gas state. And
This refrigerant passes through the switching valve 2 and the accumulator 4 and
Inhaled. On the other hand, the refrigerant which has been cooled by being exchanged heat in the first, second and third heat exchange units 19, 16a, 16b, 16c and 16d and which has been sufficiently supercooled flows into the indoor units G and H to be cooled. I do.

Here, when four indoor units B, C, D, and F are going to heat and two indoor units G and H are going to cool,
All indoor units that are trying to Chi cold tuft second relay machine I
Has been described, but when all the indoor units to be cooled are connected to the first repeater E, and when the indoor units to be cooled are the first and second repeaters E , I have the same effect.

Referring to FIG. 4, a description will be given of a case where cooling is mainly performed in simultaneous cooling and heating operation. Here, indoor unit B,
A case in which four units C, D, and F are going to cool, and two indoor units G and H are going to heat will be described. That is, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 as shown by the solid line arrows in FIG. 4 passes through the switching valve 2, any amount heat exchanger to the gas-liquid two-phase heat source unit side heat exchanger 3 The refrigerant becomes a high-temperature and high-pressure refrigerant, passes through the third check valve 32 and the second connection pipe 7, and is divided into two refrigerants: a refrigerant flowing into the relay E and a refrigerant flowing into the relay I.
One of the two refrigerants is sent to the gas-liquid separator 12 of the repeater E, where it is separated into a gaseous refrigerant and a liquid refrigerant, and the separated gaseous refrigerant passes through the gas connection pipe 50. Flows into the first branch 10 of the repeater I. The other of the two refrigerants is sent to the gas-liquid separator 12 of the repeater I, where it is separated into a gaseous refrigerant and a liquid refrigerant, and the separated gaseous refrigerant is the first refrigerant of the repeater I. The refrigerant flows into the branch portion 10 and merges with the refrigerant from the relay device E. The three-way switching valve 8 of the first branch portion 10 of the repeater I, and the first connection pipes 6g and 6h on the indoor unit side, flow into the indoor units G and H to be heated, and enter the indoor heat exchanger. At 5, heat exchange with indoor air is performed to condense and liquefy, and the room is heated. Further, the pressure is slightly reduced through the first flow control device 9 which is controlled by the degree of supercooling at the outlet of the indoor-side heat exchanger 5 and is almost fully open, and becomes an intermediate pressure between the high pressure and the low pressure (intermediate pressure). I flows into the second branch portion 11. On the other hand, the remaining liquid refrigerant separated by the gas-liquid separation device 12 flows into the second branch portion through the second flow control device 13 which is controlled to keep the difference between the high pressure and the intermediate pressure constant. .

The flow of the refrigerant to the indoor units B, C, and D to be cooled passes through the second branch section 11 of the repeater E and the second connection pipes 7b, 7c, and 7d on the indoor unit side. It flows into the indoor units B, C and D. Then, the refrigerant is reduced in pressure to a low pressure by the first flow control device 9 controlled by the degree of superheat at the outlet of the indoor heat exchanger 5 of the indoor units B, C, and D. It exchanges heat with air to evaporate and gasify and cool the room. The gaseous refrigerant is supplied to the first connection pipes 6b, 6c, 6d on the indoor unit side.
Three-way switching valve 8 connected to indoor units B, C, D, relay unit E
And flows into the first connection pipe 6 through the first branch portion 10. In addition, the flow of the refrigerant to the indoor unit F to be cooled flows into the indoor unit F through the second branch portion 11 of the repeater I and the second connection pipe 7f on the indoor unit side. Then, the refrigerant is reduced to a low pressure by the first flow control device 9 controlled by the degree of superheat at the outlet of the indoor heat exchanger 5 of the indoor unit F, and exchanges heat with the indoor air in the indoor heat exchanger 5. It evaporates and is gasified to cool the room. Then, the refrigerant in the gaseous state flows through the first connection pipe 6f on the indoor unit side, the three-way switching valve 8 connected to the indoor unit F, and the first branch portion 10 of the relay unit I, to the first branch. Flows into the connection pipe 6. In the first connection pipe 6, the refrigerant from the relay device E and the refrigerant from the relay device I merge, and are circulated into the compressor 1 via the fourth check valve 33 , the switching valve 2, and the accumulator 4. A cycle is configured and cooling-based operation is performed.

The indoor units B, C, D,
The indoor units B, C, D, and F depend on the cooling load of F.
Refrigerant flow rate flowing into is determined. Further, the flow rates of the liquid refrigerant supplied from the heat source unit A to the relay units E and I and separated by the respective gas-liquid separation devices 12 and the second branch units 11 from the indoor units G and H to be heated. And the second flow rate of each of the repeaters E and I
Indoor units B, C, which are going to be cooled from the branch portion 11 of
The liquid refrigerant flow rates flowing into D and F are always the same. Therefore, in the repeater E, the flow rate of the liquid refrigerant supplied from the gas-liquid separation device 12 to the second branch portion 11 through the second flow control device 13 and the indoor unit B to be cooled from the second branch portion 11 , C, and D, and the flow rate of the liquid refrigerant supplied from the gas-liquid separator 12 to the second branch 11 through the second flow controller 13 in the relay device I. Correct the imbalance between the flow rates of the liquid refrigerant supplied from the indoor units G and H to be heated to the second branch unit 11 and the flow amounts of the liquid refrigerant supplied to the indoor unit F to be cooled from the second branch unit. Thus, the liquid refrigerant is supplied from the repeater E to the repeater I or from the repeater I to the repeater E through the liquid connection pipe 51 according to the two imbalances.

At this time, the three-way switching valves 8 connected to the indoor units B, C, D and F have their first ports 8a closed and the second ports 8a closed.
The opening 8b and the third opening 8c are open. The three-way switching valve 8 connected to the indoor units G and H has a first port 8a and a third port 8a.
The port 8c is open and the second port 8b is closed. At this time, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, the refrigerant necessarily flows to the third check valve 32 and the fourth check valve 33.

At the time of this cycle, a part of the liquid refrigerant flows from the junction of the second connection pipes 7b, 7c, 7d on the indoor unit side to the bypass pipe 14, or the second connection pipe on each indoor unit side. The gas enters the bypass pipe 14 from the junction between the pipes 7f, 7g, and 7h. The refrigerant that has entered the bypass pipe 14 is reduced in pressure to a low pressure by the third flow control device 15,
b, 16c, 16d, the second connection pipe 7 on each indoor unit side
b, 7c, 7d or the second connection pipe 7f on each indoor unit side,
7g and 7h, and the second heat exchange section 16a
Connection pipes 7b, 7 on each indoor unit side of the branch portion 11 of FIG.
c, 7d or second connection pipes 7f, 7g on the indoor unit side,
7h, and the second heat exchange section 19
The refrigerant, which has exchanged heat with the refrigerant flowing into the flow control device 13 and evaporated, enters the first connection pipe 6, passes through the fourth check valve 33 , the switching valve 2, the accumulator 4, and the compressor 1.
Inhaled. On the other hand, the first and second and third heat exchangers 19, 16a, 16b, 16c, and 16d exchange heat and cool the refrigerant with a sufficient degree of subcooling to the indoor units B, C, and D to be cooled. , F.

Here, four indoor units B, C, D and F are for cooling, and two indoor units G and H are for heating, ie, all the indoor units for heating are the second repeater I.
Has been described, but when all the indoor units to be heated are connected to the first repeater E, and when the indoor units to be heated are the first and second repeaters E , I have the same effect.

Embodiment 2 FIG. In the above embodiment, the three-way switching valve 8 is provided to provide the first connection pipes 6b, 6c on the indoor unit side.
6d, 6f, 6g, 6h and the first connection pipe 6 or the second
The connection pipe 7 is switchably connected to the connection pipe 7. However, as shown in FIG. 5, two switching valves such as electromagnetic switching valves 30 and 31 are provided to switchably connect as described above. Similar effects can be obtained.

[0038]

As described above, the air conditioner according to the present invention comprises a single heat source unit including a compressor, a switching valve, a heat source side heat exchanger, and a plurality of indoor heat exchangers each having an indoor side heat exchanger. When the indoor unit is connected via the first and second connection pipes, the indoor unit is provided between the first and second connection pipes, and the direction of the flowing refrigerant is switched. A flow path switching valve device that lowers the pressure of the first connection pipe between the heat source unit and the indoor unit and increases the pressure of the second connection pipe, and a plurality of one or more indoor units Indoor unit constituent units, and for each indoor unit constituent unit, one of the indoor side heat exchangers is connected to a first connection pipe,
Alternatively , a first branch unit having a valve device that is switchably connected to the second connection pipe via a gas-liquid separator, and the other of the indoor heat exchangers for each indoor unit constituent unit is connected to a first unit. A second connection pipe connected to the second connection pipe via the flow control device;
And the second connection pipe, and is connected between the gas-liquid separator and the second branch for each indoor unit constituent unit.
A second flow control device that will be, branched from the second branch portion corresponding to each of the indoor units constituting units, a bypass circuit through the bypass flow control device connected to said first connection pipe, each the first corresponding to the indoor unit configuration unit, a second branch portion, the gas-liquid separator, a second flow controller, and a plurality of repeater that incorporates respectively a flow control device for及beauty bypassed, each
From the gas-liquid separator in the repeater to the valve device in the first branch
Corresponds to gas connection pipes that communicate between pipes and each repeater
Piping from the first flow control device to the second flow control device
By providing a liquid connection pipe for communicating between the heat source units, even when a large number of indoor units and a wide range are installed and connected to one heat source unit, a plurality of indoor units are connected between the heat source unit and the indoor units. Since the repeater is interposed, it is possible to obtain an air conditioner with good workability of connecting pipes and good installability of the repeater.
In both cases, the required amount of refrigerant can be supplied to the operating indoor unit more accurately and in a well-balanced manner, and the capacity of each indoor unit can be ensured.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram mainly showing a refrigerant system of an air conditioner showing a first embodiment of the present invention.

2 is an operation state diagram of only the cooling or heating of the air-conditioning apparatus shown in FIG.

FIG. 3 is a diagram showing an operation state of the air-conditioning apparatus shown in FIG. 1 mainly for heating.

FIG. 4 is an operation state diagram of the air conditioning apparatus shown in FIG. 1 mainly for cooling.

FIG. 5 is an overall configuration diagram mainly showing a refrigerant system of an air conditioner showing another embodiment of the present invention.

FIG. 6 is an overall configuration diagram mainly showing a refrigerant system of a conventional air conditioner.

7 is an operation state diagram of only the cooling or heating of the air-conditioning apparatus shown in FIG.

FIG. 8 is an operation state diagram of the air-conditioning apparatus shown in FIG. 6 mainly for heating.

9 is an operation state diagram of the air conditioning apparatus shown in FIG. 6 mainly for cooling.

[Explanation of symbols]

A Heat source unit, B, C, D, F, G, H Indoor unit, E, I
Relay machine, 1 compressor, 2 switching valve, 3 heat exchanger side heat exchanger, 5 indoor heat exchanger, 6 first connection pipe, 7
Second connection pipe, 8 valve device, 9 first flow control device, 10 first branch, 11 second branch, 12
Gas-liquid separation device, 13 second flow control device, 50 gas connection piping, 51 liquid connection piping, 60, 70 indoor unit structural unit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomohiko Kasai 6-66, Tehira, Wakayama-shi Mitsubishi Electric Corporation Wakayama Works (72) Inventor Junichi Kameyama 6-5-66, Tehira, Wakayama-shi Mitsubishi Electric Wakayama Manufacturing Co., Ltd. (56) References JP-A-3-125868 (JP, A) Jpn.

Claims (1)

(57) [Claims] 1. A first and a second connection between one heat source unit including a compressor, a switching valve, a heat source unit side heat exchanger and the like and a plurality of indoor units each having an indoor side heat exchanger. In the one connected via a pipe, each is provided between the first and second connection pipes, and by switching a direction of a flowing refrigerant, the operation is always performed between the heat source unit and the indoor unit. A flow path switching valve device that sets the first connection pipe to low pressure and sets the second connection pipe to high pressure, a plurality of indoor unit constituent units including one or a plurality of indoor units, and each indoor unit constituent unit A first branch unit having a valve device for switchably connecting one of the indoor heat exchangers to a first connection pipe or a second connection pipe via a gas-liquid separator , for each room; The other of the indoor heat exchangers for each unit
A second branch portion connected to the second connection pipe via the flow control device of the above, and the gas-liquid separation device for each indoor unit constituent unit, which is provided in the second connection pipe, and the second branch section . Between branches
A second flow control device to be connected, a bypass circuit branched from a second branch portion corresponding to each indoor unit constituent unit, and connected to the first connection pipe via a bypass flow control device; the first corresponding to each indoor unit configuration unit, a second branch portion, the gas-liquid separator, a second flow control device,及beauty plurality of relay that incorporates each bar Lee <br/> pass flow control device And the valve device at the first branch from the gas-liquid separator of each repeater
Gas connection pipes that communicate between the pipes
From the corresponding first flow control device to the second flow control device.
An air conditioner, comprising: a liquid connection pipe that communicates between pipes .