JP3029942B2 - 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 an air conditioner having a plurality of indoor units and capable of performing cooling operation, heating operation, and simultaneous cooling / heating operation.

[0002]

2. Description of the Related Art An example of a conventional air conditioner of this type is shown in FIG. In FIG. 2, 1 is a compressor, 10 is a discharge pipe, which is connected to the discharge side of the compressor 1. Reference numeral 11 denotes a suction pipe connected to the suction side of the compressor 1. Reference numeral 3 denotes an outdoor heat exchanger, the gas side of which is a discharge pipe via an outdoor switching valve 2.
It is selectively connected to 10 or the suction pipe 11. 7A, 7B and 7C are indoor heat exchangers whose gas side is an indoor switching valve 8 respectively.
It is selectively connected to the discharge pipe 10 or the suction pipe 11 via A, 8B, 8C. An outdoor throttle mechanism 4 is disposed on the liquid side of the outdoor heat exchanger 3. Reference numerals 6A, 6B, and 6C denote indoor-side throttle mechanisms, which are disposed on the liquid sides of the indoor-side heat exchangers 7A, 7B, and 7C, respectively. A liquid refrigerant pipe 12 connects the liquid side of the outdoor-side throttle mechanism 4 to the liquid sides of the indoor-side throttle mechanisms 6A, 6B, and 6C. Reference numeral 13 denotes an outdoor blower that allows outside air to flow through the outdoor heat exchanger 3. 9A, 9B, and 9C are indoor-side blowers that allow indoor air to flow through the indoor-side heat exchangers 7A, 7B, and 7C. Reference numeral 5 denotes a receiver, which is interposed in the liquid refrigerant pipe 12. 14 is accumure
And is interposed on the suction side of the compressor 1.

[0003] O is an outdoor unit including a compressor 1, an outdoor switching valve 2, an outdoor heat exchanger 3, and an outdoor blower.
13, outdoor diaphragm mechanism 4, receiver 5, accumulator 14
And so on. A, B, and C are indoor units, respectively. The indoor unit A includes an indoor heat exchanger 7A, an indoor switching valve 8A, an indoor throttle mechanism 6A, and an indoor blower 9A. The heat exchanger 7B, the indoor switching valve 8B, the indoor throttle mechanism 6B and the indoor blower 9B are built in, and the indoor unit C includes the indoor heat exchanger 7C, the indoor switching valve 8C, the indoor throttle mechanism 6C and the room. Inside blower 9C is built in. An outdoor unit O and a plurality of indoor units A, B,
C is connected to each other via a discharge pipe 10, a suction pipe 11, and a liquid refrigerant pipe 12.

When all or a part of the indoor units A, B, and C are operated in the cooling operation, for example, when the indoor units A and B are in the cooling operation and the indoor unit C is stopped, the outdoor throttle mechanism 4 is operated. It is fully opened, the indoor throttle mechanisms 6A and 6B are set to a predetermined opening degree, and the indoor throttle mechanism 6C is fully closed. The outdoor-side switching valve 2 is switched so that the outdoor-side heat exchanger 3 communicates with the discharge pipe 10.
A and 8B are switched so that the indoor heat exchangers 7A and 7B communicate with the suction pipe 11. Then, the refrigerant gas compressed by the compressor 1 enters the outdoor heat exchanger 3 via the discharge pipe 10 and the outdoor switching valve 2, and radiates heat to the outside air blown by the outdoor blower 13 to condense and liquefy. And becomes a liquid refrigerant. Next, the liquid refrigerant passes through the outdoor throttle mechanism 4 that is fully opened, enters the receiver 5, where gas components are separated. The liquid refrigerant flowing out of the receiver 5 is supplied to the liquid refrigerant pipe 12
After that, the air enters the indoor-side throttle mechanisms 6A and 6B, and is adiabatically expanded by being throttled here to become a gas-liquid two-phase. The gas-liquid two-phase refrigerant enters the indoor heat exchangers 7A and 7B, and evaporates and evaporates by cooling the indoor air blown by the indoor blowers 9A and 9B. This gas refrigerant is supplied to the indoor side switching valve 8
A, 8B, the suction pipe 11, and the accumulator 14 suck into the compressor 1.

When all or a part of the indoor units A, B, and C are operated for heating, for example, when the indoor units A and B are operated for heating and the indoor unit C is stopped, the outdoor throttle mechanism 4 and the indoor The inner throttle mechanisms 6A and 6B have a predetermined opening degree, and the indoor throttle mechanism 6C is fully closed. Then, the outdoor switching valve 2 and the indoor switching valves 8A and 8B are switched in the opposite manner to that during the cooling operation. Thus, the refrigerant discharged from the compressor 1 is condensed and liquefied in the indoor heat exchangers 7A and 7B through the discharge pipe 10, the indoor switching valves 8A and 8B, and is throttled by the indoor throttle mechanisms 6A and 6B. The adiabatic expansion is performed by the outdoor throttle mechanism 4 via the liquid refrigerant pipe 12 and the receiver 5. Next, after being evaporated and vaporized in the outdoor heat exchanger 3, the refrigerant returns to the compressor 1 through the outdoor switching valve 2, the suction pipe 11, and the accumulator 14 in this order.

In the simultaneous cooling / heating operation, when the number of indoor units performing the cooling operation is equal to the number of indoor units performing the heating operation, for example, the indoor unit C performs the cooling operation.
When the indoor unit A is in the heating operation and the indoor unit B is stopped, the outdoor throttle mechanism 4 and the indoor throttle mechanism 6B are fully closed, and the indoor throttle mechanisms 6A and 6C have a predetermined opening degree. The indoor switching valve 8A is switched to communicate with the discharge pipe 10, and the indoor switching valve 8C is switched to communicate with the suction pipe 11. Thus, the refrigerant discharged from the compressor 1 is discharged from the discharge pipe 1
0, indoor switching valve 8A, indoor heat exchanger 7A, indoor throttle mechanism 6A, liquid refrigerant piping 12, indoor throttle mechanism 6C, indoor heat exchanger 7C, indoor switching valve 8C, suction pipe 11, accumulator The flow returns to the compressor 1 through the heater 14 in this order.

In the simultaneous cooling / heating operation, if the number of indoor units for cooling operation is larger than the number of indoor units for heating operation, for example, the indoor units B and C perform cooling operation and the indoor unit A performs heating operation. In this case, the outdoor throttle mechanism 4 and the indoor throttle mechanisms 6A, 6B, 6C are set to a predetermined opening degree. The outdoor switching valve 2 and the indoor switching valve 8A are switched so as to communicate with the discharge pipe 10, and the indoor switching valves 8B and 8C are switched so as to communicate with the suction pipe 11. Thus, the refrigerant discharged from the compressor 1 branches at the point P, and a part of the liquid refrigerant passes through the discharge pipe 10L, the outdoor switching valve 2, the outdoor heat exchanger 3, the outdoor throttle mechanism 4, and the receiver 5, and Enter the pipe 12. The rest is the discharge pipe 10R, the indoor switching valve 8A, the indoor heat exchanger 7A,
The refrigerant enters the liquid refrigerant pipe 12 via the indoor throttle mechanism 6A, and merges with the refrigerant branched earlier. Next, the refrigerant is supplied to the indoor-side expansion mechanisms 6B and 6C, the indoor-side heat exchangers 7B and 7C, and the indoor-side switching valves 8B and 8C.
C, the suction pipe 11, and the accumulator 14 return to the compressor 1 in this order.

[0008]

At the time of simultaneous operation of cooling and heating of the conventional air conditioner, for example, indoor unit A is installed in cooling operation, indoor units B and C are installed in heating operation, and indoor units B and C are installed. When the indoor units B and C are thermo-off due to the room temperature of the room reaching the set temperature, the indoor blowers 9B and 9C are stopped, but the indoor throttle mechanisms 6B and 6C remain open, and Indoor switching valve 8B,
8C is still switched so as to communicate with the discharge pipe 10, so that the refrigerant that has passed through the indoor heat exchangers 7B and 7C through the indoor switch valves 8B and 8C without being condensed and liquefied is almost the same. The liquid enters the liquid refrigerant pipe 12 through the indoor side throttle mechanisms 6B and 6C. Then, since the refrigerant having a large amount of the gas flows into the indoor unit A during the cooling operation, there is a problem that the cooling capacity of the indoor unit A is reduced.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its gist is to provide a compressor and a discharge pipe connected to a discharge side of the compressor. A suction pipe connected to a suction side of the compressor, an outdoor heat exchanger, and an outdoor switching valve for selectively communicating a gas side of the outdoor heat exchanger with the discharge pipe or the suction pipe. A plurality of indoor heat exchangers; an indoor switching valve for selectively communicating the gas side of the plurality of indoor heat exchangers with the discharge pipe or the suction pipe, respectively; and An outdoor restrictor mechanism disposed on the liquid side, an indoor restrictor mechanism disposed on the liquid side of each of the plurality of indoor heat exchangers, a liquid side of the outdoor restrictor mechanism, and the plurality of indoor sides A liquid refrigerant pipe for connecting the liquid side of the throttle mechanism to a cooling operation, a heating operation, and a cooling operation. In an air conditioner capable of simultaneous heating operation, when the discharge unit and the liquid refrigerant pipe are connected via a gas bypass circuit, and when the indoor unit in the heating operation at the time of simultaneous cooling / heating operation is turned off to the gas bypass circuit, An air conditioner characterized by interposing an on-off valve that opens to the air conditioner.

[0010]

In the present invention, since the above configuration is provided, the open / close valve is opened when the indoor unit during the simultaneous cooling / heating operation and the heating operation is turned off, and the refrigerant gas is interposed in the gas bypass circuit and the gas bypass circuit. Flows into the liquid refrigerant pipe through the opened / closed valve.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIG. One end of a gas bypass circuit 16 is connected to a discharge pipe 15 of the compressor 1, and the other end of the gas bypass circuit 16 is connected to a liquid refrigerant pipe.
It is connected between the 12 outdoor diaphragm mechanisms 4 and the receiver 5. The gas bypass circuit 16 is provided with a fixed throttle 17 and an upstream / downstream opening / closing valve 18 which is opened when the indoor unit in the simultaneous heating / cooling operation and the heating operation is turned off. The other configuration is the same as that of the conventional one shown in FIG. 2, and corresponding members are denoted by the same reference numerals.

During the simultaneous operation of the air conditioner for cooling and heating, for example, when the indoor unit A is in the cooling operation, the indoor units B and C are in the heating operation, and the indoor units B and C are gas-thermo-off, the on-off valve 18 is opened. Therefore, a part of the refrigerant gas discharged from the compressor 1 branches off from the discharge pipe 15, passes through the gas bypass circuit 16, the on-off valve 18,
Flows into.

As a result, the amount of gas refrigerant flowing into the indoor units B and C via the discharge pipe 10R decreases, so that the indoor switching valves 8B and 8C and the indoor heat exchangers 7B and 7C are almost condensed. The amount of refrigerant containing a large amount of gas that flows without liquefaction and flows into the liquid refrigerant pipe 12 via the indoor-side throttle mechanisms 6B and 6C also decreases.

On the other hand, the gas refrigerant that has entered the liquid refrigerant pipe 12 through the gas bypass circuit 16 enters the receiver 5 together with the liquid refrigerant condensed and liquefied in the outdoor heat exchanger 3 and the liquid stored therein. The refrigerant is forcibly extruded and becomes a refrigerant having a large liquid content.

Thus, the amount of the refrigerant having a large amount of gas flowing through the indoor units B and C is reduced, and the amount of the refrigerant flowing out of the receiver 5 is increased and the amount thereof is increased. Since the refrigerant flowing into the indoor unit A has a large liquid content, the indoor unit A can exhibit a sufficient cooling capacity.

Note that the same applies to the case where the indoor unit during the simultaneous cooling / heating operation or the heating operation is turned off. When the on-off valve 18 is closed, a cooling operation, a heating operation, and a simultaneous cooling / heating operation are performed as in the conventional case.

One end of the gas bypass circuit 16 is connected to a discharge pipe.
10L and can be connected to the gas bypass circuit 16
Can be connected to the downstream side of the receiver 5.
Further, the fixed throttle 17 may be omitted, and the pressure may be reduced by the on-off valve 18.

[0018]

According to the present invention, the open / close valve is opened when the indoor unit during the simultaneous cooling / heating operation and the heating operation is turned off, and the refrigerant gas passes through the gas bypass circuit and the open / close valve interposed in the gas bypass circuit. As a result, the amount of gas-rich refrigerant flowing through the thermo-off indoor unit decreases, and at the same time, the amount of liquid-rich refrigerant flowing through the outdoor unit increases. As a result, since the refrigerant having a large liquid content flows into the unit during the cooling operation, it is possible to exert a sufficient cooling capacity.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of the present invention.

FIG. 2 is a system diagram of a conventional air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 10 Discharge pipe 11 Suction pipe O Outdoor unit 3 Outdoor heat exchanger 2 Outdoor switching valve 4 Outdoor throttle mechanism A, B, C Indoor units 6A, 6B, 6C Indoor throttle mechanism 7A, 7B, 7C Inside heat exchanger 8A, 8B, 8C Indoor switching valve 12 Liquid refrigerant pipe 16 Gas bypass circuit 18 On-off valve

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kazumi Honma 1 Nagoya Laboratory, Iwazuka-cho, Nakamura-ku, Nagoya-shi Nagoya Research Laboratory (72) Inventor Tokuharu Asahina Iwazuka-cho, Nagoya 1 Nagoya Laboratory, Mitsubishi Heavy Industries, Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 29/00 361 F25B 13/00 104

Claims (1)

(57) [Claims] 1. A compressor, a discharge pipe connected to a discharge side of the compressor, a suction pipe connected to a suction side of the compressor, an outdoor heat exchanger, and an outdoor heat exchanger An outdoor switching valve that selectively communicates the gas side of the discharge pipe or the suction pipe, a plurality of indoor heat exchangers, and the gas sides of the plurality of indoor heat exchangers to the discharge pipe or the An indoor switching valve for selectively communicating with the suction pipe, an outdoor throttle mechanism provided on the liquid side of the outdoor heat exchanger, and a liquid side of the plurality of indoor heat exchangers. And a liquid refrigerant pipe connecting the liquid side of the outdoor-side throttle mechanism and the liquid sides of the plurality of indoor-side throttle mechanisms, and can perform a cooling operation, a heating operation, and a simultaneous cooling / heating operation. In the air conditioner, the discharge pipe and the liquid refrigerant pipe are connected via a gas bypass circuit. An air conditioner characterized in that an on-off valve that opens when the indoor unit during the simultaneous heating / cooling operation and the heating operation is turned off is interposed in the gas bypass circuit.