KR100572598B1 - Air conditioner - Google Patents

Abstract

The air conditioner of the present invention is to ensure a proper amount of refrigerant circulation regardless of the outdoor temperature, etc. in the air conditioner capable of two-pipe air-heat mixed operation, the compressor 22, the four-way valve 23, the outdoor heat exchanger 24 and The outdoor unit 21 provided with the decompression means 25, the indoor heat exchanger 30, the plurality of indoor units 29 provided with the decompression means 31, and the heat and cold between the outdoor unit 21 and the indoor unit 29. The gas pipe 33 and the liquid pipe 34 connected through the converter 32 are provided, and the gas-liquid mixing means 26 is provided between the decompression means 25 and the liquid pipe 34 of the outdoor unit 21, and the compressor 22 is provided. And the outdoor heat exchanger 24 branch the high pressure gas branch pipe 37 so that a part of the refrigerant discharged during the cold and hot mixed operation is a liquid refrigerant, and the rest is a high pressure gas refrigerant via the high pressure gas branch pipe 37. Into each of the gas-liquid mixing means 26 to mix into a gas-liquid two-phase refrigerant through the liquid pipe 34 Inflow to the cold and warm converter 32.

Description

Air Conditioning Equipment

1 is a view showing a state during operation of the cooling main body according to an embodiment of the present invention,

2 is a view showing a state during operation of the heating subject according to an embodiment of the present invention,

3 is a view showing a conventional air conditioner.

<Description of the symbols for the main parts of the drawings>

 21: outdoor unit 22: compressor

 23: first four-way valve 24: outdoor heat exchanger

 25, 31 decompression means 26: receiver tank (gas mixture)

 27: accumulator 28: the second four-way valve

 29: indoor 30: indoor heat exchanger

 32: cold and cold converter 33: gas pipe

 34: liquid pipe 37: high pressure gas branch pipe

 39: gas-liquid separation means 41: refrigerant flow direction control mechanism

 41A to 41D: check valves constituting the refrigerant flow direction control mechanism 41

 42, 43: Connection pipe 42A, 43A: Cold / heat switching valve

The present invention relates to an air conditioner capable of operating a cold and hot air mixture of the indoor unit to perform a cooling operation and the indoor unit performing a cooling operation by installing a plurality of indoor units.

As an example of an air conditioner capable of this kind of mixed operation, a so-called two-tube type air conditioner, in which an outdoor unit and an indoor unit are connected by two lines of piping, has been proposed in Japanese Patent Publication No. 2601052 (FIG. 4). have. That is, in the air conditioner described in the patent, as shown in FIG. 3, the outdoor unit (heat source unit) 1 is a compressor 2, a four-way valve (switching valve) 3, and an outdoor heat exchanger (heat source side heat exchanger) ( 4) and the accumulator 5 or the like, and the discharge side of the compressor 2 and the suction side through the accumulator 5 and one end of the outdoor heat exchanger 4 are connected to three ports of the four-way valve 3. The remaining ports of the four-way valve 3 and the other end of the outdoor heat exchanger 4 are connected to the first and second connection pipes 7 and 8 (the two pipes) through check valves 6A to 6D, respectively. It is possible.

On the other hand, a plurality (three in the drawing) of the indoor unit (9) is composed of an indoor heat exchanger (10) and a pressure reducing means (flow control device) 11 connected thereto, respectively, and a cold and heat converter (relay unit) provided between the outdoor unit (1). (12) is connected to the outdoor unit (1) by the first and second connecting pipes (7, 8). In the heating and cooling converter 12, the first connecting pipe 7 is connected to the first branch 13, branched by each indoor unit 9, respectively, through the three-way valve (valve device) 13A, respectively, to the indoor heat exchanger ( 10). In addition, the second connecting pipe 8 is connected to the gas-liquid separation means (gas-liquid separator) 14 in the air-conditioning converter 12, and the gas pipe 14A is connected to each three-way valve at the first branch 13. While connected to the remaining port of 13A, the liquid pipe 14B is also branched by each indoor unit 9 at the second branch 15 of the heating and cooling converter 12 to decompress the means 11 of the indoor unit 9. Is connected to.

In the air conditioner configured as described above, a cooling operation is performed in a plurality (for example, two) of the plurality of indoor units (9), and a heating operation is performed in the remaining (for example, one) indoor units (9). When performing the cooling main body operation in which the cooling load in the indoor unit 9 becomes large, the outdoor unit 1 connects the discharge side of the compressor 2 and the outdoor heat exchanger 4 with the four-way valve 3, and at the same time accumulators 5) and the first connecting pipe 7 are connected via a check valve 6B. In the air conditioner 12, the indoor unit 6 (two indoor units 9 on the right side in FIG. 3) and the first connection pipe which perform cooling operation by the three-way valve 13A of the first branch 13 are provided. While connecting (7), the indoor unit 9 (one indoor unit 9 on the left side in FIG. 3) that performs the heating operation is connected to the gas pipe 14A.

Accordingly, the refrigerant discharged from the compressor 2 during the operation of the cooling main body is partially condensed by the outdoor heat exchanger 4 via the four-way valve 3 as indicated by arrows in FIG. It becomes the gas-liquid two-phase refrigerant of and flows into the gas-liquid separation means 14 of the cold / heat converter 12 via the check valve 6A via the second connecting pipe 8. The liquid refrigerant in the gas-liquid two-phase refrigerant introduced into the gas-liquid separating means 14 is branched from the second branch part 15 via the liquid pipe 14B and introduced into the indoor unit 9 performing the cooling operation. After the pressure is reduced by the decompression means 11, the indoor heat exchanger 10 is cooled to cool the room. On the other hand, the high-pressure gas refrigerant of the gas-liquid two-phase refrigerant from the gas-liquid separation means 14 to the three-way valve (13A) connected to the indoor unit (9) to perform the heating operation of the first branch portion 13 through the gas pipe (14A). After passing through the indoor unit (9) and condensed in the indoor heat exchanger (10) to heat the room, and joins the liquid refrigerant flowing into the indoor unit (9) that is cooled and operated in the second branch (15) Used for cooling by (9).

However, when performing the cooling main body operation as described above in the air conditioner disclosed in the Japanese Patent Publication No. 26051052, the inflow into the gas-liquid separation means 14 of the air-conditioning converter 12 from the second connecting pipe 8 is performed. The gas-liquid two-phase refrigerant that is generated is caused by partially condensing the refrigerant discharged from the compressor (2) by reducing the condensation capacity of the outdoor heat exchanger (4) by reducing the air volume of the fan provided in the outdoor unit (1). As a result, it was inevitable that the flow rate ratio of the high-pressure gas refrigerant and the liquid refrigerant varied depending on the outdoor temperature or the like. For this reason, the flow rate of the high-pressure gas refrigerant and the liquid refrigerant flowing into the indoor unit 9 which is operated by cooling and heating from the gas-liquid separating means 14 through the gas pipe 14A and the liquid pipe 14B in the cooling and heating converter 12 is performed. Since it will also be different, it is difficult to ensure a proper amount of refrigerant circulation for each operation of cooling and heating.

In addition, since the gas-liquid two-phase refrigerant flowing into the indoor unit 9 is passed through the interior of the outdoor heat exchanger 4 once, and then sent to the gas-liquid separation means 14 of the cold / heat converter 12, in particular, when the outdoor temperature is low. The condensation pressure of the gas-liquid two-phase refrigerant after passing through the outdoor heat exchanger 4 is lowered, so that in the case of the high-pressure gas refrigerant flowing into the indoor unit 9 being heated, there is a possibility that a sufficient condensation temperature cannot be secured. In addition, the heating capability of the indoor unit 9 in the heating operation may be deteriorated.

SUMMARY OF THE INVENTION The present invention has been made under such a background. In an air conditioner capable of operating a two-pipe mixed air conditioner in which an outdoor unit and an indoor unit are connected by two pipes, an appropriate amount of refrigerant circulation is ensured regardless of the outdoor temperature, such as during the operation of the cooling main body. It aims at providing the air conditioning apparatus which can ensure the reliable heating capability of the indoor unit heated by heating.

In order to solve the above problems and to achieve the above object, the present invention provides an outdoor unit having a compressor, a four-way valve, an outdoor heat exchanger, and a decompression means, a plurality of indoor units having an indoor heat exchanger and a decompression means, and the outdoor unit and an indoor unit. An air conditioner having a gas pipe and a liquid pipe connected between air conditioner and air conditioner, wherein an indoor and air conditioner performing a cooling operation in a plurality of indoor units and an indoor unit performing a heating operation are mixed, wherein the outdoor unit includes: A gas-liquid mixing means is provided between the decompression means of the outdoor unit and the liquid pipe, and the high-pressure gas branch pipe is branched between the compressor and the outdoor heat exchanger to cool the refrigerant discharged from the compressor during the hot and cold mixed operation, a part of which is the outdoor heat exchanger. And flowing into the gas-liquid mixing means as a liquid refrigerant through the decompression means of the outdoor unit. The rest is introduced into the cold and heat converter through the liquid pipe as a gas-liquid two-phase refrigerant by flowing into the gas-liquid mixing means as a high-pressure gas refrigerant through the high-pressure gas branch pipe and mixed with the liquid refrigerant. A gas-liquid separation means for separating a refrigerant into a liquid refrigerant and a high pressure gas refrigerant may be provided in the liquid pipe to introduce the liquid refrigerant into an indoor unit performing the cooling operation, and to introduce the high pressure gas refrigerant into the indoor unit performing the heating operation.

Therefore, in the air conditioner of the present invention configured as described above, as described above, a part of the refrigerant discharged from the outdoor unit compressor is condensed by the outdoor heat exchanger to be introduced as a liquid refrigerant, and the remainder is not passed through the outdoor heat exchanger, and the high pressure gas branch pipe is not passed through. The gas-liquid mixing means is introduced into the gas-liquid mixing means while being mixed with the liquid refrigerant to form a gas-liquid two-phase refrigerant through the liquid pipe and into the gas-liquid separation means of the air-conditioning converter. The flow rate ratio of the refrigerant is not influenced by the outdoor temperature as in the prior art, but the liquid refrigerant and the high pressure gas are controlled by the amount of the refrigerant flowing into the gas-liquid mixing means from the outdoor unit through the outdoor heat exchanger and the amount of the refrigerant flowing into the gas-liquid mixing means through the high pressure gas branch pipe. It is possible to secure proper refrigerant circulation in all the refrigerants. It is possible to perform a predetermined cold-heat mixed operation, and in particular, it is possible to prevent the deterioration of the heating capability of the indoor unit that is heated and operated during the cooling main body operation. Meanwhile, the refrigerant used for cooling and heating in the indoor unit is circulated to the outdoor unit through the gas pipe and returned to the suction side of the compressor.

Here, the gas-liquid mixing means may be such that the high pressure gas branch pipe is simply connected to a pipe connecting the outdoor heat exchanger and the liquid pipe, and the liquid refrigerant passing through the pipe and the high pressure gas refrigerant branched into the high pressure gas branch pipe are mixed. If a receiver tank is provided between the decompression means and the liquid pipe, it is also possible to use this receiver tank as a gas-liquid mixing means.

In addition, in the air conditioner of the present invention, the flow rate of the liquid refrigerant and the high-pressure gas refrigerant introduced into and mixed with the gas-liquid mixing means can be controlled by the pressure-reducing means of the outdoor unit from the gas-liquid mixing means to the gas-liquid separation means of the cold and heat converter. By adjusting the flow rate ratio of the liquid refrigerant and the high-pressure gas refrigerant of the gas-liquid two-phase refrigerant to be introduced, it is possible to secure an appropriate amount of refrigerant circulation more reliably, and in particular, to control the heating capability of the indoor unit as described above. That is, the pressure reduction means of the outdoor unit is required when the heating load is increased on the indoor unit side and the heating capacity is increased by enabling the flow rate to be controlled by using an adjustable opening degree such as an electromagnetic expansion valve. It is possible to increase the flow rate of the refrigerant to the high-pressure gas branch pipe by reducing the opening degree of the gas and increase the flow rate of the refrigerant to the indoor unit for heating operation, thereby increasing its heating capacity. On the contrary, when the heating load on the indoor unit is reduced, the opening degree of the decompression means of the outdoor unit is reduced to decrease the refrigerant flow rate to the high-pressure gas branch pipe, thereby reducing the refrigerant flow rate to the indoor unit for heating operation, thereby suppressing the heating capacity. .

Further, in the outdoor unit, the high pressure gas branch pipe is connected to the gas-liquid mixing means through a second four-way valve, the high-pressure gas refrigerant is introduced into the gas-liquid mixing means via the second four-way valve, and the gas pipe is sucked into the compressor. If the gas pipe is connected to the compressor discharge side by switching the second four-way valve and the four-way valve (hereinafter referred to as the first four-way valve), the two-pipe air conditioner as described above is cooled. • Since the refrigerant flow path switching on the outdoor unit side at the time of heating operation switching can be performed by the first and second two-way valves, the outdoor unit valve mechanism and piping structure can be simplified.

When the gas pipe is connected to the discharge side and the suction side of the compressor, in particular, the flow direction of the refrigerant flowing through the gas pipe is reversed before and after the change and thus the flow direction of the refrigerant flowing through the liquid pipe is also changed. In the opposite direction. Therefore, in this case, the plurality of connection pipes are connected to the gas-liquid separation means and the gas pipe through a check valve in the air-conditioning switch so that the flow direction of the refrigerant flowing into the indoor unit becomes one direction during the cooling and heating operation. A refrigerant flow direction control mechanism is connected to each of the indoor heat exchangers of the indoor unit through a cold and hot diversion valve, and controls the flow direction of the refrigerant flowing into the hot and cold diversion valve through the connecting pipe in one direction by the check valve. In particular, by configuring the flow direction control mechanism of the refrigerant by the check valve as described above, the valve mechanism can be simplified even in the hot and cold switching side.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. 1 and 2 illustrate one embodiment of the present invention. In the present embodiment, the outdoor unit 21 includes a compressor 22, a first four-way valve 23, an outdoor heat exchanger 24, and a pressure reducing means 25 corresponding to four-way valves in the air conditioner according to claim 1 of the present invention. ), A receiver tank 26, an accumulator 27, and a second four-way valve 28, and a plurality of indoor units 29 are provided (four in this embodiment), respectively, in series with the indoor heat exchanger 30. It is provided with a decompression means (31) connected to each other, the indoor unit (29) and the outdoor unit (21) by the gas pipe 33 and the liquid pipe (34) through the air-conditioning switch 32 provided between the outdoor unit (21) Connected.

In the outdoor unit 21, a first port 23A of the first four-way valve 23 is connected to the discharge side of the compressor 22 through an oil separator 35, and the second port 23B is the outdoor unit. It is connected to the receiver tank 26 via the heat exchanger 24 and the decompression means 25, and the said receiver tank 26 is connected to the said liquid pipe 34, and forms the gas-liquid mixing means in this embodiment. On the other hand, the outdoor heat exchanger 24 in the present embodiment has a configuration in which heat exchangers divided into a plurality (two in the drawing) are connected in parallel to each other. However, it is also possible to use a single heat exchanger which is not divided in this way. As the decompression means 25 of the outdoor unit 21, an adjustable opening degree such as an electromagnetic expansion valve is used, and between the outdoor heat exchanger 24 and the receiver tank 26, a solenoid valve or the like is used. The on-off valve 36A formed is connected in series with the check valve 36B and in parallel with the decompression means 25.

In this embodiment, the high pressure gas branch pipe 37 branches between the second port 23B of the first four-way valve 23 and the outdoor heat exchanger 24. It is connected to the 1st port 28A of the 2nd four-way valve 28 via 37A of open / close valves, such as a valve. In addition, the second port 28B of the second four-way valve 28 is also connected to the receiver tank 26 through an opening / closing valve 37B such as a solenoid valve, so that the high pressure gas branch pipe 37 is It is possible to connect with the receiver tank 26 as the gas-liquid mixing means via the second four-way valve 28. On the other hand, a check valve 37C is provided between the open / close valve 37A of the high pressure gas branch pipe 37 and the second four-way valve 28.

In the first four-way valve 23, the third port 23C is connected between the check valve 37C and the second four-way valve 28 of the high-pressure gas branch pipe 37 through the check valve 38. The fourth port 23D is connected to the suction side of the compressor 22 via the accumulator 27. In the second four-way valve 28, the third port 28C is connected to the gas pipe 33, and the fourth port 28D is also connected to the suction side of the compressor 22 through the accumulator 27. have. The first four-way valve 23 has a first port 23A and a second port 23B connected to each other, and a third port 23C and a fourth port 23D connected to each other. 28 The first port 28A and the second port 28B are also interconnected, and the third port 28C and the fourth port 28D are interconnected, while the first and second four-way valves ( By switching the 23 and 28, respectively, the first four-way valve 23 has its first port 23A and the third port 23C interconnected, and the second port 23B and the fourth port 23D mutually connected. And the second four-way valve 28 may be configured such that the first port 28A and the third port 28C are interconnected and the second port 28B and the fourth port 28D are interconnected. have.

On the other hand, in the heating and cooling converter 32, gas-liquid separation means 39 having a gas pipe 39A and a liquid pipe 39B is connected to the liquid pipe 34, wherein the liquid pipe 39B is an electromagnetic valve or the like. The plurality of indoor units 29 are branched to each of the plurality of indoor units 29 through the on / off valve 39C, and are connected to the decompression means 31 each including an expansion valve. A check valve 40A is connected to the liquid pipe 39B in series with a decompression means 40B made of a capillary tube or the like, and is connected in parallel with the on-off valve 39C. On the other hand, instead of combining the check valve 40A and the decompression means 40B such as the capillary tube, for example, an expandable decompression means such as an electric expansion valve may be connected in parallel with the on / off valve 39C. Configuration is also possible.

In addition, the gas pipe (39A) of the gas pipe 33 and the gas-liquid separation means 39 is branched into two in the cold and heat converter 32, the first and the second pair of check valves through the check valve (41A ~ 41D), respectively. Both ends of the connection pipes 42 and 43 are connected. That is, one of the branched gas pipes 33 is connected to one end of the first connecting pipe 42 through the check valve 41A, while the other of the branched gas pipes 33 is connected to the second through the check valve 41B. One end of the branched gas pipe 39A connected to one end of the pipe 43 is connected to the other end of the first connecting pipe 42 via the check valve 41C and the other of the branched gas pipe 39A. The side is connected to the other end of the second connecting pipe 43 via the check valve 41D. In addition, the first and second connection pipes 42 and 43 are heat exchanger valves 42A and 43A formed of solenoid valves or the like for each of the plurality of indoor units 29, respectively. 30).

Here, the check valves 41A to 41D are formed in directions in which check valves 41A and 41C provided at both ends of the first connection pipe 42 prevent the inflow of refrigerant from the first connection pipe 42 side. On the other hand, check valves 41B and 41D provided at both ends of the second connecting pipe 43 are installed in a direction to prevent refrigerant from flowing into the second connecting pipe 43. In this embodiment, the flow direction of the refrigerant flowing into the indoor unit 29 which performs the heating operation from the connection pipe 42 via the cold / heat switching valve 42A by the check valves 41A to 41D in one direction. The flow direction control mechanism 41 of the refrigerant which controls the flow direction of the refrigerant flowing into the connecting pipe 43 through the air-conditioning switching valve 43A from the indoor unit 29 which performs the cooling operation and controls the air in one direction is constituted. It is.

 In the case of performing the cold / heat mixed operation by the air conditioner of the present embodiment configured as described above, first, as shown in FIG. 1, many of the plurality of indoor units 29 (three in the upper side in FIG. 1) are cooled and operated. As in the case of the cooling main body operation having a large cooling load in the plurality of indoor units 29 as in the case where the remaining indoor units 29 (one of the lowermost ones in FIG. 1) are heated, the first of the outdoor units 21 as described above. The first port 23A and the second port 23B are connected to the four-way valve 23, and the third port 23C and the fourth port 23D are connected, and the second four-way valve 28 is also connected. The first port 28A and the second port 28B are connected and the third port 28C and the fourth port 28D are connected. In addition, the open / close valves 37A and 37B of the high pressure gas branch pipe 37 are opened and the open / close valve 36A is closed.

On the other hand, the cooling and heating converter 32 performs the cooling operation among the cooling and heating switching valves 42A and 43A provided between the indoor heat exchanger 30 and the first and second connection pipes 42 and 43 of each indoor unit 29. In the case of the indoor unit 29, the heating and cooling switching valve 42A provided on the first connecting pipe 42 side is closed, and the heating and cooling switching valve 43A provided on the second connecting pipe 43 side opens. In the case of the indoor unit 29 which performs the operation, the air-conditioning switching valve 42A provided in the 1st connection pipe 42 side opens, and the air-conditioning switching valve 43A provided in the 2nd connection pipe 43 side is closed. In addition, the opening / closing valve 39C provided in the liquid pipe 39B of the gas-liquid separating means 39 is opened.

Therefore, the refrigerant discharged from the compressor 22 of the outdoor unit 21 passes through the first and second ports 23A and 23B of the first four-way valve 23 as indicated by arrows in FIG. Condensed in the air 24 to the liquid refrigerant flows into the receiver tank 26 through the decompression means 25 of the outdoor unit 21, while the remainder is branched to the high-pressure gas branch pipe 37 while the high-pressure gas refrigerant It also flows into the receiver tank 26 via the first and second ports 28A and 28B of the second four-way valve 28. In the receiver tank 26, the liquid refrigerant and the high-pressure gas refrigerant are mixed and introduced into the gas-liquid separation means 39 of the cold / heat converter 32 as the gas-liquid two-phase refrigerant.

As such, the gas-liquid two-phase refrigerant introduced into the gas-liquid separating means 39 is separated into the liquid refrigerant and the high-pressure gas refrigerant in the gas-liquid separating means 39 again, and the liquid refrigerant performs the cooling operation through the liquid pipe 39B. The air is introduced into a plurality of indoor units 29, respectively, and the pressure is reduced by the decompression means 31 to evaporate in the indoor heat exchanger 30 to cool the room, and then, as the low pressure gas refrigerant through the open / cold switching valve 43A. 2 flows into the tube 43. Meanwhile, the separated high-pressure gas refrigerant flows into the first connection pipe 42 through the check valve 41C via the gas pipe 39A, and performs an heating operation through the cold / heat switching valve 42A that is continuously opened ( 29) and condensed in the indoor heat exchanger 30 to heat the room, and then join the liquid refrigerant introduced into the liquid pipe 39B as the liquid refrigerant and introduced into the indoor unit 29 performing the cooling operation. It is used for cooling the room.

In addition, the low pressure gas refrigerant introduced into the second connecting pipe 43 from the indoor unit 29 performing the cooling operation as described above, the check valve 41D provided at the other end of the second connecting pipe 43 is a gas pipe ( Since it is closed by the high-pressure gas refrigerant flowing from 39A, it flows into the gas pipe 33 through the check valve 41B provided at one end. In this way, the low pressure gas refrigerant introduced into the gas pipe 33 is returned to the outdoor unit 21 through the accumulator 27 via the third and fourth ports 28C and 28D of the second four-way valve 28. Circulated to the suction side of (22).

Meanwhile, as shown in FIG. 2, a plurality of indoor units 29 (three in the lower side in FIG. 2) are heated and heat the remaining indoor units 29 (one in the uppermost side in FIG. 2) as shown in FIG. 2. When the heating main body is operated with a large heating load in the plurality of indoor units 29 as in the case of cooling operation, first and second four-way valves 23 and 28 of the outdoor unit 21 are different from the cooling main body operation. Is switched differently so that in the first four-way valve 23, the first port 23A and the third port 23C are connected, while the second port 23B and the fourth port 23D are connected, and the second four-way valve is connected. Also at (28), the first port 28A and the third port 28C are connected and the second port 28B and the fourth port 28D are connected. In addition, the open / close valves 37A and 37B of the high pressure gas branch pipe 37 are closed. In addition, in the heating and cooling converter 32, the air-conditioning switching valve 42A of the indoor unit 29 performing the cooling operation is closed and the air-conditioning switching valve 43A is opened and the heating operation of the indoor unit 29 is performed as in the cooling main operation. The hot and cold switching valve 42A is opened, the hot and cold switching valve 43A is closed, and the on-off valve 39C is closed.

Accordingly, the refrigerant discharged from the compressor 22 of the outdoor unit 21 during the operation of the heating main body is a high-pressure gas refrigerant as indicated by an arrow in FIG. 23C) flows into the high pressure gas branch pipe 37, and then flows into the gas pipe 33 through the first and third ports 28A and 28C of the second four-way valve 28. The high-pressure gas refrigerant flows into the first connecting pipe 42 through the check valve 41A from the heating and cooling converter 32 and into the indoor unit 29 which performs the heating operation through the opening / closing valve 42A, respectively. After condensation by the indoor heat exchanger (30), the room is heated and then flows into the liquid pipe (39B) as a liquid refrigerant.

In addition, a part of the liquid refrigerant introduced into the liquid pipe 39B is introduced into the indoor unit 29 performing the cooling operation, decompressed by the decompression means 31, and evaporated in the indoor heat exchanger 30, thereby cooling the room. It is used as a low pressure gas refrigerant flows into the second connecting pipe 43 through the cold and hot diversion valve 43A. Here, since the check valve 41B provided at one end of the second connecting pipe 43 is closed by the high pressure gas refrigerant flowing into the gas pipe 33, the low pressure gas refrigerant flowing into the second connecting pipe 43 is It flows into the gas-liquid separation means 39 via the gas pipe 39A through the check valve 41D at the other end. On the other hand, the remaining liquid refrigerant flowing into the liquid pipe 39B is also introduced into the gas-liquid separation means 39 through the check valve 40A and the decompression means 40B. In this way, the refrigerant introduced into the gas-liquid separating means 39 is returned to the outdoor unit 21 through the liquid pipe 34 and introduced into the receiver tank 26, and then continues by the decompression means 25 of the outdoor unit 21. The reduced pressure may be evaporated in the outdoor heat exchanger 24 and circulated to the suction side of the compressor 22 through the accumulator 27 via the second and fourth ports 23B and 23D of the first four-way valve 23.

On the other hand, when performing a balanced operation of cooling and heating loads, such as the case where the number of cooling operation units and the number of heating operation units among the plurality of indoor units 29 are the same, for example, when the outdoor temperature is low, the outdoor unit 21 side may have the first and Connection of the first to fourth ports 23A to 23D and 28A to 28D of the second four-way valves 23 and 28 is the same as in the operation of the heating main body, the closing valves 37A and 37B are also closed and the air conditioner 32 ) Open and close the air-conditioning switching valves 42A and 43A, respectively, in the same manner as in the air-conditioning main body operation in accordance with the air-conditioning / heating operation on the indoor unit 29 side. In this case, the refrigerant discharged from the compressor 22 is the first and third ports 23A and 23C of the first four-way valve 23, the high pressure gas branch pipe 37 and the second four-way valve as in the heating main operation. The first and the third ports 28A and 28C of 28 are introduced into the heating and cooling converter 32 through the gas pipe 33 and the heating operation is first performed through the first connecting pipe 42 via the check valve 41A. It is supplied to the indoor unit 29 to perform condensation and used for heating indoors, and then flows into the liquid pipe 39B as a liquid refrigerant.

Thereafter, the liquid refrigerant flows into the indoor unit 29 performing the cooling operation through the liquid pipe 39B, and is decompressed by the decompression means 31 to be evaporated in the indoor heat exchanger 30 to be used for cooling the room. After flowing into the connecting pipe 43, the gas is passed through the gas pipe 39A through the check valve 41D to the gas-liquid separating means 39, and then returned to the outdoor unit 21 through the liquid pipe 34 to receive the receiver tank 26. Circulation through the accumulator 27 to the suction side of the compressor 22 via the pressure reducing means 25, the outdoor heat exchanger 24, and the second and fourth ports 23B and 23D of the first four-way valve 23. do. On the contrary, when the outdoor temperature is high, the balance operation can be performed by the same connection as that of the cooling main body operation. In this way, if the connection is made in the same way as any one of the cooling and heating operation according to the outdoor temperature, the cooling load increases when the outdoor temperature is high, or conversely, when the heating load is increased when the outdoor temperature is low, 2 Without switching the four-way valves 23 and 28, it is possible to quickly shift to the cooling main body operation or the heating main body operation.

In the case of cooling all the indoor units 29, on the outdoor unit 21 side, the ports 23A to 23D and 28A to 28D of the first and second four-way valves 23 and 28 are connected in the same manner as the operation of the cooling main body. At the same time, the on-off valves 37A and 37B of the high-pressure gas branch pipe 37 are closed and the on-off valve 36A is opened. In the air-conditioning converter 32, all the cold-heat switching valves 42A are closed and the cold-heat switching valve 43A is opened. . Therefore, in this case, all of the refrigerant discharged from the compressor 22 is introduced into the outdoor heat exchanger 24 and condensed, so that the refrigerant is introduced into the indoor unit 29 through the cooling and heating converter 32 through the liquid pipe 34 as a liquid refrigerant, and then indoors. After being used for cooling, the gas is returned to the outdoor unit 21 through the gas pipe 33. On the other hand, when all the indoor units 29 are heated and operated, the first and second four-way valves 23 and 28 are the same as in the heating main operation, so that the on-off valves 37A and 37B of the high-pressure gas branch pipe 37 are also It opens and closes the heating and cooling switching valve 42A of the heating and cooling diverter 32, and the heating and cooling switching valve 43A is closed. In this case, the refrigerant is a high-pressure gas refrigerant flowing through the outdoor unit 21 through the gas pipe 33 to the cold and heat converter 32, condensed in the indoor heat exchanger 30 of all the indoor unit 29 to heat the room and then liquid refrigerant It returns to the outdoor unit 21 through the liquid pipe 34 as a.

Therefore, in the air conditioner having such a configuration, the pipe connecting the outdoor unit 21 and the air conditioner 32 on the indoor unit 29 is composed of two pipes, the gas pipe 33 and the liquid pipe 34, so that the piping construction is easy and the cooling operation is performed. And heating and cooling can be carried out with either one of the heating operations or the balance of both loads, thereby enabling air conditioning according to the needs of each room. In addition, in such a cold-heat mixed operation, the heat discharged to the outside during cooling can be used for heating, or the heat introduced from the outside during heating can be introduced from the room requiring cooling, thereby reducing the load on the outdoor unit 21 side. Efficient and economical mixed operation of cold and cold can be performed.

In the air conditioner of the present embodiment, a part of the refrigerant discharged from the compressor 22 of the outdoor unit 21 is used as the liquid refrigerant through the outdoor heat exchanger 24 during the air-conditioning operation, particularly during the cooling main body operation described above. Entering into the receiver tank (gas-liquid mixing means) 26 and the remaining refrigerant to the receiver tank (gas-liquid mixing means) 26 also through the high-pressure gas branch pipe 37 as a high-pressure gas refrigerant without passing through the outdoor heat exchanger (24). The liquid refrigerant and the high pressure gas refrigerant are mixed in the receiver tank 26 and flow into the gas-liquid separation means 39 of the cold and heat converter 32 through the liquid pipe 34 as the gas-liquid two-phase refrigerant. A refrigerant circulation amount appropriate for the gas refrigerant can be ensured. As a result, the flow rate ratio of the liquid refrigerant and the high pressure gas refrigerant in the gas-liquid two-phase refrigerant can be prevented from being influenced by the outdoor temperature. Thus, even when the outdoor temperature is low, the high pressure gas refrigerant with the proper pressure and flow rate can be secured. Sufficient heating performance can be given to the indoor unit 29 which performs a heating operation at the time of a cooling main body operation.

In the present embodiment, the pressure reducing means 25 provided between the receiver tank 26 serving as the gas-liquid mixing means and the outdoor heat exchanger 24 in the outdoor unit 21 can adjust the opening of the valve like the electromagnetic expansion valve. The flow rate of the liquid refrigerant and the high-pressure gas refrigerant flowing into the receiver tank 26 and mixed during the operation of the cooling main body can be controlled by the decompression means 25. Therefore, the liquid pipe 34 from the receiver tank 26 can be controlled. The flow rate ratio of the liquid refrigerant and the high-pressure gas refrigerant of the gas-liquid two-phase refrigerant flowing into the gas-liquid separation means 39 of the air-conditioning converter 32 through) is adjusted by the decompression means 25, in particular, the heating of the indoor unit to perform the heating operation. You're in control of your abilities. That is, for example, when the heating load on the indoor unit 29 side increases, and thus the heating capacity of the indoor unit 29 needs to be increased, the opening degree of the valve in the decompression means 25 is reduced so as to reduce the pressure from the compressor 22. Among the discharged refrigerants, the amount of liquid refrigerant flowing into the receiver tank 26 through the outdoor heat exchanger 24 is decreased, and the amount of the high pressure gas refrigerant flowing into the receiver tank 26 by branching through the high pressure gas branch pipe 37 is reduced. By increasing the flow rate ratio of the high-pressure gas refrigerant in the gas-liquid two-phase refrigerant to increase the amount of high-pressure gas refrigerant flowing into the indoor unit 29 for heating operation from the gas-liquid separation means 39 through the gas pipe 39A You can control the ability to increase.

On the other hand, when the heating load on the indoor unit 29 side decreases, the valve opening degree of the decompression means 25 is increased to condense in the outdoor heat exchanger 24 among the refrigerant discharged from the compressor 22 during the operation of the cooling main body. The amount of liquid refrigerant flowing into the receiver tank 26 through the decompression means 25 increases, and conversely, the high pressure gas refrigerant that branches through the high pressure gas branch pipe 37 without passing through the outdoor heat exchanger 24 decreases. Since the flow rate ratio of the high-pressure gas refrigerant in the gas-liquid two-phase refrigerant mixed in the receiver tank 26 is reduced, the amount of refrigerant flowing into the indoor unit 29 performing the heating operation can be reduced to suppress the heating capability. . Therefore, according to the present embodiment, the liquid tank and the high pressure gas refrigerant are mixed in the receiver tank 26 so as to achieve an optimum flow ratio according to the ratio of the cooling load and the heating load in the plurality of indoor units 29 even during the operation of the cooling main body. By constituting the phase refrigerant, both air-conditioning and air-conditioning capacity can be secured to meet the needs of the room, and in particular, as described above, it is possible to reliably control the heating capacity of the indoor unit 29 that performs the heating operation.

In the air conditioner of the present embodiment, the receiver tank 26 for holding the liquid refrigerant once is used as the gas-liquid mixing means for mixing the liquid refrigerant and the high-pressure gas refrigerant in the outdoor unit 21. Therefore, for example, the high pressure gas branch pipe 37 is directly connected to a pipe connected from the pressure reducing means 25 of the outdoor unit 21 to the liquid pipe 34 to mix the liquid refrigerant and the high pressure gas refrigerant or the receiver tank 26. Another tank connected to the high-pressure gas branch pipe 37 and the like may be used between the liquid pipe 34 and the liquid pipe 34, and the same may be used as the gas-liquid mixing means, but the receiver tank 26 may be gas-liquid mixing means as in the present embodiment. In this case, the configuration of the device can be simplified compared to the case of installing other tanks, etc., and the mixing of the liquid refrigerant and the high-pressure gas refrigerant can be more reliably compared with the case where the high-pressure gas branch pipe 37 is directly connected to the liquid refrigerant pipe. The gas-liquid two-phase refrigerant having a stable flow rate ratio can be obtained.

On the other hand, in the present embodiment, the first and second two-way valves 23 and 28 are provided in the outdoor unit 21, and the high-pressure gas branch pipe 37 is the second four-way valve during the cooling main body operation. 28 is connected to the receiver tank 26 as the gas-liquid mixing means, and the gas pipe 33 into which the low-pressure gas refrigerant flows from the cold / heat converter 32 is also supplied to the compressor 22 through the second four-way valve 28. It is connected to the suction side of the. When switching to heating main operation or the like, by switching the first and second four-way valves 23 and 28, the gas pipe 33 is connected to the discharge side of the compressor 22 through the high-pressure gas branch pipe 37 and the liquid pipe. 34 is connected to the suction side of the compressor 22 via an outdoor heat exchanger 24 or the like, so that the high-pressure gas branch pipe 37 branches as described above to be connected to the receiver tank 26 as gas-liquid mixing means. In the case of the two-pipe air conditioner, the switching of the cooling / heating operation can be achieved by the first and second four-way valves 23 and 28 on the outdoor unit 21 side. The piping structure can be simplified.

In the present embodiment, the gas pipe 33 and the liquid pipe 34 are connected to the compressor 22 by the first and second four-way valves 23 and 28 on the outdoor unit 21 side in the cooling and heating operation. By switching to the discharge side and the suction side, the flow direction of the refrigerant flowing through the gas pipe 33 and the liquid pipe 34 is also reversed in accordance with the switching of the cooling and heating operations. Both ends of the gas pipes 33 and the gas pipes 39A of the gas-liquid separation means 39 are connected to both ends so that the flow direction of the refrigerant flowing into the valves 42A and 43A is always one direction. First and second pairs of connecting pipes 42 and 43 connected to the indoor heat exchanger 30 of the indoor unit 29 through 43A) are provided in the cold / heat converter 32, and the connecting pipes 42 and 43 ) And check valves 41A to 41D provided between the gas pipe 33 and the gas pipe 39A. Constitute a control mechanism 41 for controlling the flow direction of the refrigerant. Accordingly, as the flow direction of the refrigerant is controlled by the combination of the check valves 41A to 41D in this way, the valve mechanism can be simplified even on the cold / heat converter 32 side, and for example, the air described in Patent Document 1 above. It is possible to promote cost savings by eliminating the need for expensive three-way valves for switching between cooling and heating operations, such as air conditioners.

As described in detail above, according to the present invention, in the air-conditioning and air-conditioning apparatus in which the outdoor unit and the indoor unit are connected to the air-conditioning switch of the gas and liquid pipes, a part of the refrigerant discharged from the compressor of the outdoor unit is transferred to the outdoor heat exchanger. While condensing into a liquid refrigerant, the remainder is branched through a high-pressure gas branch pipe and mixed with the liquid refrigerant in the gas-liquid mixing means in the state of a high-pressure gas refrigerant to form a gas-liquid two-phase refrigerant. Appropriate amount of refrigerant circulation can be secured for both refrigerants, and in particular, it is possible to prevent the loss of the heating capacity of the indoor unit that performs the heating operation due to the outdoor temperature, etc., during the operation of the cooling main body, and to prevent the cooling and heating of the indoors. It is possible to achieve reliable air conditioning according to demand.

In addition, by using the receiver tank as the gas-liquid mixing means, it is possible to simplify the structure of the apparatus and to ensure the gas-liquid mixing. In addition, since the flow rate of the liquid refrigerant and the high pressure gas refrigerant flowing into the gas-liquid mixing means can be controlled by the decompression means of the outdoor unit, the flow rate ratio between the liquid refrigerant and the high pressure gas refrigerant in the gas-liquid two-phase refrigerant can be further optimized. ㆍ Refrigerant circulation amount corresponding to each heating load can be secured more reliably, and in particular, the heating capacity control in the indoor unit which performs heating operation can be aimed at.

Further, a second four-way valve is installed in the outdoor unit to connect the high pressure gas branch pipe and the gas-liquid mixing means, and the first four-way valve provided on the discharge side of the second four-way valve and the compressor to the discharge side and the suction side of the gas pipe compressor. By making the connection switchable, the outdoor unit structure can be simplified. In addition, even in the case where such a configuration is adopted, even when the flow direction of the refrigerant in the gas and liquid pipes is reversed by switching between cooling and heating operations, the flow direction control mechanism of the refrigerant constituted by the check valve on the air-conditioning switch side In addition, the flow direction of the refrigerant flowing into the hot and cold switching valve can always be oriented in one direction, and the valve mechanism can be simplified or the cost can be reduced.

Claims (5)

An outdoor unit having a compressor, a four-way valve, an outdoor heat exchanger, and a decompression means, A plurality of indoor units having an indoor heat exchanger and a decompression means, It has a gas pipe and a liquid pipe connected between the outdoor unit and the indoor unit through a cold and heating converter, An air conditioner capable of operating a cold and hot air mixture in which indoor units performing a cooling operation and indoor units performing a heating operation in the plurality of indoor units are mixed. In the outdoor unit, a gas-liquid mixing unit is provided between the decompression unit and the liquid pipe of the outdoor unit, and a high-pressure gas branch pipe is branched between the compressor and the outdoor heat exchanger. A part is introduced into the gas-liquid mixing means as liquid refrigerant through the outdoor heat exchanger and the decompression means of the outdoor unit, and the other is introduced into the gas-liquid mixing means as the high-pressure gas refrigerant through the high-pressure gas branch pipe and mixed with the liquid refrigerant. As a gas-liquid two-phase refrigerant flows into the cold and heat converter through the liquid pipe,  In the cooling and heating converter, a gas-liquid separating means for separating a gas-liquid two-phase refrigerant into a liquid refrigerant and a high-pressure gas refrigerant is provided in the liquid pipe so that the liquid refrigerant flows into the indoor unit performing the cooling operation, and the indoor unit in which the high-pressure gas refrigerant performs the heating operation. Air conditioning apparatus, characterized in that flowed into. The method of claim 1, And the gas-liquid mixing means is a receiver tank provided between the decompression means of the outdoor unit and the liquid pipe. The method according to claim 1 or 2, And a flow rate of the liquid refrigerant and the high-pressure gas refrigerant introduced into and mixed with the gas-liquid mixing means is controlled by the decompression means of the outdoor unit. The method according to claim 1 or 2, In the outdoor unit, the high-pressure gas branch pipe is connected to the gas-liquid mixing means through a second four-way valve so that the high-pressure gas refrigerant flows into the gas-liquid mixing means via the second four-way valve and the gas pipe is sucked into the compressor. And the gas pipe is connected to the discharge side of the compressor by switching between the second four-way valve and the four-way valve. The method according to claim 1 or 2, In the cooling and heating converter, a pair of connecting pipes respectively connected to the gas-liquid separating means and the gas pipe through check valves are respectively connected to the indoor heat exchangers of the plurality of indoor units through cooling and heating switching valves, And an air flow direction control mechanism for controlling the flow direction of the refrigerant flowing through the connecting pipe in one direction by the check valve.

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