KR20140000936A - Multi-air conditioner for heating and cooling operations at the same time - Google Patents

Abstract

The air-conditioning simultaneous multi air conditioner according to the embodiment of the present invention includes a plurality of air-conditioning combined indoor units each including an indoor heat exchanger, a compressor, an outdoor heat exchanger, and a switching unit arranged at the discharge side of the compressor to switch the flow of refrigerant. It is disposed between the air-conditioning combined outdoor unit and the air-conditioning combined outdoor unit and the air-conditioning combined indoor unit, and the refrigerant to the air-conditioning combined room according to the air conditioning room, heating all rooms, cooling subjects simultaneously, and heating subjects simultaneously operating conditions A distributor for distributing a liquid header, a low pressure gas header, a high pressure gas header through which a refrigerant having a higher pressure than the refrigerant in the low pressure gas header, and a high pressure refrigerant of the high pressure gas header are supplied to the low pressure gas header. A bypass pipe for passing and the high pressure gas header disposed on the bypass pipe. Standing hayeoseo includes the low pressure gas flow rate control in a header for controlling the flow rate of the refrigerant by-pass parts, it is possible to prevent the freezing of the indoor unit.

Description

Multi-air conditioner for heating and cooling operations at the same time}

The present invention relates to a simultaneous heating and cooling multi air conditioner, and more particularly to a cooling and heating simultaneous multi air conditioner that can prevent freezing of the indoor unit by bypassing the refrigerant from the high pressure gas pipe connected to the outdoor unit to the low pressure gas pipe. .

In general, a multi-type air conditioner connects a plurality of indoor units to one outdoor unit, and each of the plurality of indoor units is used as a cooler or a heater while using the outdoor unit in common.

Recently, a plurality of compressors are provided or a plurality of outdoor units are connected to each other in parallel so as to effectively cope with cooling or heating loads according to the number of indoor units.

The multi-air conditioner according to the prior art includes a plurality of outdoor units, a plurality of indoor units, and a refrigerant pipe connecting the plurality of outdoor units and indoor units, wherein the plurality of outdoor units are a main outdoor unit and a plurality of sub units. It consists of an outdoor unit.

Each of the plurality of outdoor units includes a compressor for compressing a low-temperature, low-pressure gaseous refrigerant to high temperature and high pressure, an outdoor heat exchanger for exchanging circulated refrigerant with outdoor air, and a four-way valve for switching refrigerant flow according to cooling or heating operation. Is installed. Each of the plurality of indoor units is provided with an expansion mechanism and an indoor heat exchanger for heat-exchanging refrigerant circulated with indoor air.

In the multi-air conditioner according to the related art, the refrigerant compressed by the compressor of the main outdoor unit and the sub outdoor unit is sent to the outdoor heat exchanger by the four-way valve during the cooling operation, and the refrigerant passing through the outdoor heat exchanger After condensation by heat exchange with air, it is sent to the expansion mechanism. The refrigerant expanded in the expansion mechanism flows into the indoor heat exchanger and evaporates while absorbing heat of indoor air, thereby cooling the room.

In the heating operation, the flow path is switched in the four-way valve, and the refrigerant discharged from the compressor passes through the four-way valve, the indoor heat exchanger, the outdoor linear expansion valve (LEV), and the outdoor heat exchanger in order. Will be heated.

However, the conventional air-conditioning simultaneous multi air conditioner has a problem that the refrigerant remains in the high-pressure gas pipe during the air-conditioning and cooling chamber operation.

In addition, in the simultaneous operation of the heating subjects or the simultaneous operation of the cooling subjects, even when the outdoor temperature is low, some spaces may not require cooling. At this time, if the temperature of the refrigerant supplied to the indoor unit is too low for cooling, the indoor unit freezes.

The problem to be solved by the present invention is to provide a simultaneous air-conditioning multi-air conditioner capable of effectively heating and cooling at the same time even when the temperature of the outside air is low.

In order to achieve the above object, the air-conditioning simultaneous multi air conditioner according to an embodiment of the present invention is a plurality of air-conditioning combined indoor units each including an indoor heat exchanger, a compressor, an outdoor heat exchanger and the discharge side of the compressor is disposed of the refrigerant It is arranged between the air-conditioning combined outdoor unit and the air-conditioning combined outdoor unit and the air-conditioning combined indoor unit including a switching unit for switching the flow, and the refrigerant is supplied to the air-conditioning chamber, the heating chamber, the air-cooling subjects simultaneously, and the heating subjects simultaneously operating conditions. And a distributor for distributing the combined air-conditioning and indoor units, wherein the distributor includes a liquid header, a low pressure gas header, a high pressure gas header through which a refrigerant having a higher pressure than a refrigerant in the low pressure gas header, and a high pressure refrigerant of the high pressure gas header. A bypass pipe for bypassing the gas to the low pressure gas header, and And a flow rate control unit disposed to control a flow rate of the refrigerant bypassed from the high pressure gas header to the low pressure gas header.

According to the air-conditioning simultaneous multi air conditioner of the present invention, there are one or more of the following effects.

The embodiment has the effect of opening the electromagnetic expansion valve installed in the bypass pipe during the cooling chamber operation, bypassing the refrigerant remaining in the high pressure gas header to the low pressure gas header to prevent the refrigerant from running out of the system.

In addition, while cooling the space (for example, the computer room) that requires cooling at the outdoor temperature (particularly winter) that requires the heating of the room, it is possible to prevent freezing of the indoor unit during the cooling operation.

In addition, there is no need to turn off the air-conditioning simultaneous multi air conditioner to prevent freezing of the indoor unit during the cooling operation, there is an advantage that the continuous operation of the air-conditioning simultaneous multi-air conditioner.

1 is a schematic configuration diagram of a cooling and heating simultaneous multi air conditioner according to an exemplary embodiment of the present invention.
FIG. 2 is an operation diagram illustrating an operating state of the air-conditioning simultaneous multi air conditioner of FIG.
3 is an operation diagram showing an operating state of the air-conditioning simultaneous multi air conditioner of FIG.
4 is an operation diagram showing an operating state of the air-conditioning simultaneous multi air conditioner of FIG.
5 is an operation diagram showing an operating state of the air-conditioning simultaneous multi air conditioner of FIG.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" Can be used to easily describe the correlation of components with other components. Spatially relative terms should be understood as terms that include different orientations of components during use or operation in addition to those shown in the drawings. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element . Thus, the exemplary term "below" can include both downward and upward directions. The components can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises "and / or" comprising ", as used herein, unless the recited component, step, and / or step does not exclude the presence or addition of one or more other elements, steps and / I never do that.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

In the drawings, the thickness and the size of each component are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size and area of each component do not entirely reflect actual size or area.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described.

1, there is shown a cooling and heating simultaneous multi air conditioner 100 according to an embodiment of the present invention. The air-conditioning simultaneous multi-air conditioner 100 includes first, second, third and fourth air-conditioning combined indoor units B1, B2, B3, and B4, a combined air-conditioning outdoor unit A, and a distributor C.

The combined outdoor air conditioner (A) includes first and second compressors 53 and 54, an outdoor heat exchanger 51, an outdoor heat exchanger fan 61, and a switching unit. Here, the switching unit includes a four-way valve (62). Suction portions of the first and second compressors 53 and 54 are connected by a common accumulator 52. The first compressor 53 is an inverter compressor capable of varying the compression capacity of the refrigerant, and the second compressor 54 is a constant speed compressor having a constant compression capacity of the refrigerant.

First and second discharge pipes 55 and 56 are connected to discharge parts of the first and second compressors 53 and 54, and the first and second discharge pipes 55 and 56 are connected to the lamination part 57. By the first and second discharge pipes 55 and 56, the first and second oil separators 58 and 59 are configured to recover oil from the refrigerant discharged from the first and second compressors 53 and 54. Each is installed. In the first and second oil separators 58 and 59, the first and second oil separators 58 and 59 guide oil separated from the first and second oil separators 58 and 59 to the suction part of the first and second compressors 53 and 54. , 2 oil recovery pipes 30 and 31 are connected.

The high pressure gas pipe 63 for connecting the refrigerant 57 discharged from the first and second compressors 53 and 54 to bypass the four-way valve 62 is connected to the lamination part 57. In addition, the lamination portion 57 is connected to the four-way valve 57 and the third discharge pipe (68).

The outdoor heat exchanger 51 is connected to the four-way valve 62 by the first connection pipe 71. In the outdoor heat exchanger 51, the refrigerant is condensed or evaporated by heat exchange with outside air. At this time, in order to make the heat exchange more smoothly, the outdoor unit fan 61 flows air into the outdoor heat exchanger 51. In the air-conditioning simultaneous multi air conditioner (100), the outdoor heat exchanger (51) is used as the condenser during the cooling room operation or the simultaneous operation of the cooling main body. Used as

On the liquid pipe 72 connecting the outdoor heat exchanger 51 and the distributor C, an outdoor electromagnetic expansion valve 65 and a supercooling device 66 are provided. The outdoor electromagnetic window valve 65 expands the refrigerant during the heating of all the rooms or the simultaneous operation of the heating subjects. The supercooling device 66 cools the refrigerant moved to the distributor C during the cooling chamber operation or the simultaneous operation of the cooling main body. The outdoor electromagnetic expansion valve 74 transfers the refrigerant condensed in the first, second, third, and fourth indoor heat exchangers 11, 21, 32, and 41 to the outdoor heat exchanger 51 during all the heating operation or simultaneous heating operation. Inflate before entering. The subcooler 66 is configured to cover a portion of the liquid pipe 72, and a portion of the refrigerant that is disposed between the subcooler 66a and the distributor C and moves to the distributor C. Bypass piping 66b for bypassing the subcooler 66a, electromagnetic expansion valve 66c provided in the bypass piping 66b, and subcooler 66a and the third discharge pipe 64 are connected. And a recovery pipe 66d.

The distributor C is disposed between the air-conditioning combined outdoor unit A and the first, second, third and fourth air-conditioning combined indoor units B1, B2, B3, and B4, and the refrigerant is cooled in an air-cooling room, a heating room, and a cooling room. It distributes to the indoor units B1, B2, B3, and B4 which combines both heating and cooling according to the subject simultaneous and heating subject simultaneous operating conditions. Dispenser C includes a high pressure gas header 81, a low pressure gas header 82, a liquid header 83 and control valves (not shown).

The first, second, third and fourth indoor units B1, B2, B3, and B4 are the first, second, third and fourth indoor heat exchangers 11, 21, 31, and 41, respectively. 1, 2, 3, 4 indoor expansion valves 12, 22, 32, 42 and 1, 2, 3, 4 indoor fans 15, 25, 35, 45 Include. The first, second, third and fourth indoor expansion valves 12, 22, 32 and 42 are the first, second, third and fourth indoor heat exchangers 11, 21, 31 and 41. And the first, second, third and fourth indoor connection pipes 13, 23, 33 and 43 for connecting the high pressure gas header 81 to each other.

The first, second, third and fourth temperature sensors 16 may detect the temperature of the refrigerant discharged from the first, second, third and fourth indoor units B1, B2, B3, and B4. (26) 36 (46) may be installed. Here, the first, second, third and fourth temperature sensors 16, 26, 36 and 46 may be connected to the first, second, third and fourth indoor heat exchangers 11, 21, 31 and 41. It is provided on the fifth, sixth, seventh and eighth indoor connection pipes 14, 24, 34 and 44 which connect the low pressure gas header 82. In addition, temperature sensors (not shown) may also be installed in the first, second, third and fourth indoor heat exchangers 11, 21, 31, and 41.

The high pressure gas header 81 is connected to one side of the high pressure gas pipe 63 of the lamination part 57 and the first, second, third and fourth indoor heat exchangers 11, 21, 31 and 41, respectively. do. In addition, the low pressure gas header 82 is connected to the suction pipe 64 by the low pressure gas pipe 75, and the first, second, third and fourth indoor heat exchangers 11, 21, 31 and 41 It is connected to the other side. The liquid header 83 is connected to one side of the subcooler 66 and the first, second, third and fourth indoor heat exchangers 11, 21, 31 and 41, respectively. The high pressure gas header 81, the low pressure gas header 82, and the liquid header 83 have a high pressure gas pipe 63 ', a low pressure gas pipe 75', and a liquid pipe 72 'of another outdoor unit (not shown). Each may be further connected.

The bypass pipe 84 is provided between the high pressure gas header 81 and the low pressure gas header 82. The bypass pipe 84 serves to bypass the high pressure refrigerant of the high pressure gas header 81 to the low pressure gas header 82.

On the bypass pipe 84, a flow rate controller for controlling the flow rate of the refrigerant bypassed from the high pressure gas header 81 to the low pressure gas header 82 is provided. The flow rate control unit controls the flow rate of the refrigerant bypassed from the high pressure gas header 81 to the low pressure gas header 82 to prevent freezing of the indoor unit during the cooling operation during the simultaneous operation of the heating subjects or the simultaneous operation of the cooling subjects. Alternatively, the flow rate control unit is opened during the operation of the cooling chamber to bypass the residual refrigerant remaining in the high pressure gas header 81 to the low pressure gas header 82. Flow control unit may be an electronic expansion valve (85).

2 to 5, the operation of the air-conditioning simultaneous multi air conditioner shown in FIG. 1 and the flow of the refrigerant according to this will be described.

Figure 2 shows the operation of the air-conditioning simultaneous multi-air conditioner 100 and the refrigerant flow according to the air conditioning room operation. The refrigerant of the high pressure gas discharged from the first and second compressors 53 and 54 flows through the first and second discharge pipes 55 and 56, and then passes through the third discharge pipe 68 and the four-way valve 62. And flows into the outdoor heat exchanger (51). The high pressure liquid refrigerant condensed in the outdoor heat exchanger 51 flows into the liquid header 83 through the subcooler 66. The refrigerant discharged from the liquid header 83 through the first, second, third, and fourth indoor connection pipes 13, 23, 33, and 43 may include the first, second, third, and fourth indoor expansion valves. 12) after being expanded in 22, 32, 42, and evaporated in the first, second, third and fourth indoor heat exchangers 11, 21, 31, 41, low pressure gas header 82 Flows into. The low pressure gas refrigerant discharged from the low pressure gas header 82 flows into the suction discharge pipe 64 and is then sucked into the first and second compressors 53 and 54 through the accumulator 52.

Here, during the cooling chamber operation, the refrigerant does not flow into the high pressure gas header 81 so that the refrigerant remains in the high pressure gas header 81. At this time, the electromagnetic expansion valve 85 provided in the bypass pipe 84 is opened to bypass the refrigerant remaining in the high pressure gas header 81 to the low pressure gas header 82. Therefore, the refrigerant remains in the high pressure gas header 81 during the cooling chamber operation, thereby preventing the refrigerant from running out of the system.

Figure 3 shows the operation of the air-conditioning simultaneous multi-air conditioner 100 and the flow of the refrigerant according to the heating in all the room operation. The refrigerant of the high pressure gas discharged from the first and second compressors 53 and 54 flows through the first and second discharge pipes 55 and 56 and does not flow into the four-way valve 62, but the lamination part 57 and The high pressure gas pipe 63 passes through the high pressure gas header 81. The refrigerant discharged from the high-pressure gas header 81 through the fifth, sixth, seventh and eighth indoor connection pipes 14, 24, 34 and 44 may be the first, second, third and fourth indoor heat exchangers. Condensation at (11) (21) (31) (41). Thereafter, the refrigerant flows into the liquid header 83, is discharged through the liquid pipe 72, expanded in the outdoor electromagnetic expansion valve 65, and then evaporated in the outdoor heat exchanger 51. The low temperature low pressure gas refrigerant flows into the suction pipe 64 through the four-way valve 62 and is then sucked into the first and second compressors 53 and 54 through the accumulator 52.

During the heating of the entire room, the refrigerant flows into the low pressure gas header 82 to close the electromagnetic expansion valve 85 in order to prevent the refrigerant from running short in the air-conditioning simultaneous multi-air conditioner 100.

Figure 4 shows the operation of the air-conditioning simultaneous multi air conditioner 100 and the flow of the refrigerant according to the simultaneous operation of the cooling main subject. For convenience of explanation, it is assumed that the first, second, and third rooms B1, B2, and B3 operate in the cooling mode, and the fourth room B4 operates in the heating mode. The flow of the refrigerant for operating the first, second, and third rooms B1, B2, and B3 in the cooling mode is the same as the flow of the refrigerant in the air conditioner room operation. Hereinafter, description will be focused on the matters different from those in FIG. 2.

A portion of the high pressure gas refrigerant discharged from the first and second compressors 53 and 54 flows through the lamination part 57 and flows through the high pressure gas pipe 63, and then flows into the high pressure gas header 81. The refrigerant flowing out of the high pressure gas header 81 flows through the eighth indoor connecting pipe 44, and then condenses in the fourth indoor heat exchanger 41 and flows into the liquid header 83. In the liquid header 83, both the refrigerant passing through the fourth chamber B4 and the refrigerant passing through the outdoor heat exchanger 51 flow in to flow into the first, second, and third chambers B1, B2, and B3. do.

Here, the cooling operation is performed when the indoor unit (for example, the first, second, and third indoor rooms B1, B2, and B3) that is in the cooling operation falls below a predetermined temperature (-5 ° C) during the simultaneous operation of the cooling subjects. Freezing occurs in the indoor unit in operation. Such freezing lowers the efficiency and reliability of the air-conditioning simultaneous multi air conditioner (100). In order to prevent this, the opening value of the electromagnetic expansion valve 85 is adjusted to prevent freezing of the indoor unit (for example, the first, second, and third indoor rooms B1, B2, and B3) during the cooling operation.

Specifically, the opening value of the electromagnetic expansion valve 85 is adjusted so that the temperature of the refrigerant discharged from the indoor unit during the cooling operation maintains the preset temperature (-5 ° C.) or more. Preferably, the temperature sensors (first, second and third temperature sensors 16 and 26) installed in the discharge portion of the indoor unit (for example, the first, second and third indoor rooms B1, B2 and B3) which are in cooling operation. (36)) detects the coolant temperature of the discharge portion of the indoor unit during the cooling operation, if the temperature of the coolant is lower than the predetermined temperature, by detecting it to adjust the opening value of the electromagnetic expansion valve 85, the high-pressure gas header The high pressure and high temperature gas of 81 is bypassed to the low pressure gas header 82, so that the temperature of the low pressure gas refrigerant in the low pressure gas header 82 rises. After repeating this process every predetermined time, the temperature of the refrigerant supplied to the indoor unit during the cooling operation is controlled to a predetermined temperature or more.

Therefore, while cooling the space (for example, the computer room) which needs cooling at the outdoor temperature (for example, winter season) which requires indoor heating, the freezing of the indoor unit in cooling operation can be prevented. In addition, in order to prevent freezing of the indoor unit during the cooling operation, there is no need to turn off the air-conditioning simultaneous multi air conditioner 100, and continuous operation is possible.

5 shows the operation of the simultaneous heating and cooling simultaneous multi-air conditioner 100 and the flow of the refrigerant according to the heating subject. For convenience of explanation, it is assumed that the first, second, and third rooms B1, B2, and B3 operate in a heating mode, and the fourth room B4 operates in a cooling mode. The flow of the refrigerant for operating the first, second, and third indoor rooms B1, B2, and B3 in the heating mode is the same as the flow of the refrigerant in all the heating room operations. However, after the high-pressure liquid refrigerant flows into the fourth chamber B4 from the liquid header 83 through the fourth interior connection pipe 43, the fourth chamber B4 expands in the fourth interior electromagnetic expansion valve 42 and the fourth chamber heat exchanger. After evaporation in the group 41, it is introduced into the low pressure gas header 82. Thereafter, the refrigerant flows through the low pressure gas pipe 75, flows into the third discharge pipe 64, and mixes with the refrigerant evaporated in the outdoor heat exchanger 51.

Here, if the indoor unit (for example, the fourth indoor B4) in the cooling operation is lowered below a predetermined temperature (-5 ° C) during the simultaneous heating of the heating subjects, freezing occurs in the indoor unit during the cooling operation. Such freezing lowers the efficiency and reliability of the air-conditioning simultaneous multi air conditioner (100). In order to prevent this, the opening value of the electromagnetic expansion valve 85 is adjusted to prevent freezing of the indoor unit during the cooling operation.

Specifically, to adjust the opening value of the electromagnetic expansion valve 85 so that the temperature of the refrigerant discharged from the indoor unit (for example, the fourth indoor B4) during the cooling operation maintains the preset temperature (-5 ° C) or more. do. Preferably, the temperature sensor (fourth degree sensor 46) installed in the discharge unit of the indoor unit during the cooling operation senses the refrigerant temperature of the discharge unit of the indoor unit during the cooling operation, and when the temperature of the refrigerant becomes lower than the preset temperature, When sensing and adjusting the opening value of the electromagnetic expansion valve 85, the high-pressure high-temperature gas of the high-pressure gas header 81 is bypassed to the low-pressure gas header 82, so that the temperature of the low-pressure gas refrigerant in the low-pressure gas header 82 is Will rise. Since the process is repeated every predetermined time, the temperature of the refrigerant supplied to the indoor unit during the cooling operation is controlled to a predetermined temperature or more.

Therefore, while cooling a space (for example, a computer room) requiring cooling at an outdoor temperature requiring indoor heating, it is possible to prevent freezing of the indoor unit during cooling operation. In addition, in order to prevent freezing of the indoor unit during the cooling operation, there is no need to turn off the air-conditioning simultaneous multi air conditioner 100, and continuous operation is possible.

Although the above has been illustrated and described with respect to the preferred embodiment of the present invention, the present invention is not limited to the above-described specific embodiment, but in the technical field to which the invention belongs without departing from the gist of the invention as claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims (8)

A plurality of air-conditioning combined indoor units each including an indoor heat exchanger;
An outdoor unit for both cooling and heating, including a compressor, an outdoor heat exchanger, and a switching unit disposed on the discharge side of the compressor to switch the flow of the refrigerant; And
A divider disposed between the air-conditioning combined outdoor unit and the air-conditioning combined indoor unit, and configured to distribute the refrigerant to the air-conditioning combined indoor units according to the air-conditioning room, the heating room, the air-cooling main body, and the heating main body simultaneously operating conditions,
The distributor,
A liquid header;
A low pressure gas header;
A high pressure gas header through which a refrigerant having a higher pressure than the refrigerant in the low pressure gas header flows;
A bypass pipe for bypassing the high pressure refrigerant of the high pressure gas header to the low pressure gas header;
And a flow rate control unit disposed on the bypass pipe and configured to control a flow rate of the refrigerant bypassed from the high pressure gas header to the low pressure gas header. The method of claim 1,
The flow rate control unit is a simultaneous air-conditioning multi air conditioner including an electronic expansion valve. 3. The method of claim 2,
Cooling and heating simultaneous multi-air conditioner further comprises a temperature sensor for sensing the temperature of the refrigerant discharged from the combined air-conditioning and indoor unit. 3. The method of claim 2,
In the simultaneous operation of the heating subjects or the simultaneous operation of the cooling subjects,
Cooling and heating simultaneous multi air conditioner for adjusting the opening value of the electromagnetic expansion valve to prevent freezing of the indoor unit during the cooling operation. The method of claim 3,
In the simultaneous operation of the heating subjects or the simultaneous operation of the cooling subjects,
And a simultaneous heating and cooling type multi-air conditioner for controlling the opening value of the electromagnetic expansion valve so that the temperature of the refrigerant discharged from the combined air-conditioning and indoor units maintains a predetermined temperature or more. 3. The method of claim 2,
At the time of the cooling room operation,
Cooling and heating simultaneous multi air conditioner for opening the electronic expansion valve. 3. The method of claim 2,
In the heating all room driving,
Air conditioning city-type multi air conditioner for closing the electronic expansion valve. The method of claim 3,
Wherein the temperature sensor comprises:
Cooling and heating simultaneous multi air conditioner is installed in the pipe connecting the indoor heat exchangers and the low-pressure gas header.

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