JP2971223B2 - 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 whose gas side is selectively connected to a discharge pipe 10 or a suction pipe 11 via an outdoor switching valve 2, respectively. 7A, 7
B and 7C are indoor heat exchangers, and the gas side is selectively connected to the discharge pipe 10 or the suction pipe 11 via the indoor switching valves 8A, 8B and 8C, respectively. 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. Reference numeral 12 denotes a liquid refrigerant pipe, which is an outdoor throttle mechanism 4.
Is connected to the liquid side of the plurality of indoor side throttle mechanisms 6A, 6B, 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. Numeral 14 denotes an accumulator which 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 vaporized 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]

In the conventional air conditioner described above, when the cooling and heating operations are performed simultaneously, for example, when the indoor units A and B are operated in the cooling operation and the indoor unit C is operated in the heating operation, the compressor 1 Refrigerant discharged from the compressor 1
, The amount of gas refrigerant supplied to the indoor heat exchanger 7C of the indoor unit C that is heated and operated is reduced. As a result, there is a problem that the heating capacity of the indoor unit C decreases and energy is wasted from the outdoor heat exchanger 3 unnecessarily.

[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 discharger connected to a discharge side of the compressor. A pipe, a suction pipe connected to the suction side of the compressor,
A plurality of outdoor heat exchangers having different capacities from each other, a plurality of indoor heat exchangers, and an outdoor which selectively communicates the gas side of the plurality of outdoor heat exchangers to the discharge pipe or the suction pipe, respectively. A switching valve, 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, and a liquid side of the plurality of outdoor heat exchangers. The outdoor-side restrictor mechanism, the indoor-side restrictor mechanisms respectively disposed on the liquid side of the plurality of indoor-side heat exchangers, the liquid-side of the plural outdoor-side restrictor mechanisms, and the plurality of indoor-side restrictor mechanisms. An air conditioner having a liquid refrigerant pipe connecting the liquid side and a cooling operation, a heating operation, and a cooling / heating operation at the same time, an outdoor switching unit connected to a gas side of an outdoor heat exchanger having a smallest capacity. A capillary tube is interposed between the valve and the discharge pipe In the air conditioner, characterized in that the.

[0010]

In the present invention, when the air conditioner is operated simultaneously with cooling and heating, particularly when the number of indoor units to be cooled is substantially equal to the number of indoor units to be heated, the gas discharged from the compressor is controlled. When the refrigerant flows into the outdoor heat exchanger having the smallest capacity through the discharge pipe, the capillary tube, and the outdoor switching valve in this order, the flow is suppressed by the flow resistance of the capillary tube. A large amount of refrigerant gas is distributed to the indoor heat exchanger.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIG. The outdoor unit O has a plurality of (two in the figure) outdoor heat exchangers 3A and 3B having different capacities, and the outdoor side switching valves 2A and 2B are provided on the gas side, and the outdoor side heat exchangers are provided on the liquid side. Outer diaphragm mechanisms 4A and 4B are provided. Further, a capillary tube 18 is interposed between the discharge pipe 10 and the outdoor switching valve 2B connected to the gas side of the outdoor heat exchanger 3B having the smallest capacity. The other configuration is the same as that of the conventional one shown in FIG. 2, and the corresponding members are denoted by the same reference numerals and description thereof will be omitted.

In the simultaneous operation of cooling and heating, particularly when the number of indoor units performing cooling operation is substantially equal to the number of indoor units performing heating operation, for example, the indoor units A and B perform cooling operation and indoor unit C When the heating operation is performed, the outdoor-side throttle mechanism 4A is fully closed, and the outdoor-side switching valve 2B is switched so that the indoor-side heat exchanger 3B communicates with the discharge pipe 10. Then, the indoor switching valves 8A and 8B are switched so as to communicate with the suction pipe 11, and the indoor switching valve 8C is switched so as to communicate with the discharge pipe 10. Then, the gas refrigerant discharged from the compressor 1 is branched at a point P, and one of the branches is connected to a discharge pipe.
10L, the capillary tube 18, the outdoor switching valve 2B, the indoor heat exchanger 3B, the outdoor throttle mechanism 4B, the liquid refrigerant piping 12 via the receiver 5, and the other is the discharge pipe 10R, the indoor switching valve 8C,
The refrigerant enters the liquid refrigerant pipe 12 via the indoor heat exchanger 7C and the indoor throttle mechanism 6C, and merges with the refrigerant branched earlier. Next, this refrigerant is supplied to the indoor-side expansion mechanisms 6A and 6B and the indoor-side heat exchangers 7A and 7A.
B, indoor switching valve 8A, 8B, suction pipe 11, accumulator 14
And returns to the compressor 1. At this time, the refrigerant gas discharged from the compressor 1 tends to flow into the outdoor heat exchanger 3B close to the compressor 1, but tends to flow into the outdoor heat exchanger 3B due to the flow resistance of the capillary tube 18. Since the amount of the refrigerant gas is suppressed, the amount of the refrigerant gas distributed to the indoor heat exchanger 7C increases. Thus, the amount of heat radiation of the indoor heat exchanger 7C increases, and it is possible to prevent a decrease in the heating capacity of the indoor unit C and to reduce the heat radiated to the outside air from the outdoor heat exchanger 3B to contribute to energy saving. it can.

[0013]

[0014]

According to the present invention, when the air conditioner is simultaneously operated for cooling and heating, particularly when the number of indoor units to be cooled and the number of indoor units to be heated are substantially equal,
When the gas refrigerant discharged from the compressor flows into the outdoor heat exchanger having the smallest capacity via the capillary tube and the outdoor switching valve, the flow is suppressed by the flow resistance of the capillary tube. A large amount of refrigerant gas can be distributed to the indoor heat exchanger of the unit. As a result, it is possible to prevent a decrease in the heating capacity of the indoor unit to be heated and to reduce the heat that is discarded from the outdoor heat exchanger having the smallest capacity to the outside air, thereby contributing to energy saving. And since this capillary tube is inexpensive, and is interposed in the system path from the discharge pipe to the outdoor heat exchanger having the smallest capacity, cooling,
During full capacity operation of the heating, the capacity of the outdoor unit is not significantly reduced.

[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 3A, 3B Outdoor heat exchanger A, B, C Indoor unit 7A, 7B, 7C Indoor heat exchanger 12 Liquid refrigerant piping 2A, 2B Outdoor switching valve 8A, 8B, 8C Indoor switching valve 4A, 4B Outdoor throttle mechanism 6A, 6B, 6C Indoor throttle mechanism 18 Throttle mechanism

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takayuki Kobayashi 3-1-1 Asahicho, Nishibiwajima-cho, Nishi-Kasugai-gun, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Aircon Works (56) References JP-A-3-7853 (JP JP-A-2-78870 (JP, A) JP-A-60-205153 (JP, A) JP-A-52-167645 (JP, U)

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, a plurality of outdoor heat exchangers having different capacities , A plurality of indoor heat exchangers, an outdoor switching valve for selectively communicating a gas side of the plurality of outdoor heat exchangers with the discharge pipe or the suction pipe, respectively, and a plurality of indoor heat exchangers. an indoor side switching valve for selectively communicating the gas side, each said discharge pipe or intake pipe, and said plurality of outdoor heat exchangers respectively disposed on the liquid side by the chamber outer side throttle mechanism, the plurality of chambers an indoor side throttle mechanism to the liquid side of the inner heat exchanger disposed respectively, and a liquid refrigerant pipe connecting the liquid side of the plurality of outdoor side throttle mechanism of the liquid side and the plurality of indoor side throttle mechanism comprises ,
Air conditioning for cooling operation, heating operation, and simultaneous cooling / heating operation
Gas in the outdoor heat exchanger with the smallest capacity
Calibration between the connected to the side exterior side switching valve and the discharge pipe
An air conditioner characterized by interposing a spiral tube .