JPH094940A - Multi-heat pump type air conditioner - Google Patents

Abstract

PURPOSE: To prevent the cooling capacity from being lowered by introducing gas refrigerant leaked from an indoor unit into the indoor unit during cooling operation when the heating operation of the indoor unit of heating during cooling and heating concurrent operation is stopped. CONSTITUTION: First solenoid valves 21A, 21B, 21C which are closed in the heating stop mode of cooling and heating concurrent operation are provided at the liquid sides of indoor side throttle mechanisms 6A, 6B, 6C. The other ends of bypass tubes 22A, 22B, 22C connected with one ends of the valves 21A, 21B, 21C and the mechanisms 6A, 6B, 6C are connected to a suction gas tube 11, and second solenoid valves 23A, 23B, 23C to be opened in a heating stop mode at the time of the cooling and heating concurrent operation are respectively provided at the tubes 22A, 22B, 22C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-type heat pump type air conditioner having one outdoor unit and a plurality of indoor units and capable of 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, and 10 is a discharge gas pipe, which is connected to the discharge side of the compressor 1. A suction gas pipe 11 is connected to the suction side of the compressor 1. 3 is an outdoor heat exchanger, the gas side of which is selectively connected to the discharge gas pipe 10 or the suction gas pipe 11 via the outdoor switching valves 18 and 2.

Reference numerals 7A, 7B and 7C denote indoor heat exchangers, the gas sides of which are respectively connected to the branch discharge gas pipes 10A, 10B and 10C through the indoor switching valves 13A, 13B and 13C or the branch intake air. Indoor side switching valve 8A, which is installed in the gas pipes 11A, 11B, 11C,
It is selectively connected to the discharge gas pipe 10 or the suction gas pipe 11 via 8B and 8C.

An outdoor throttling mechanism 4 is an outdoor heat exchanger 3.
It is arranged on the liquid side of. Reference numerals 6A, 6B, and 6C denote indoor throttle mechanisms, which are provided on the liquid sides of the indoor heat exchangers 7A, 7B, and 7C, respectively. A liquid refrigerant pipe 12 connects the liquid side of the outdoor side expansion mechanism 4 and the liquid side of the indoor side expansion mechanisms 6A, 6B, 6C.

Reference numeral 16 denotes an outdoor blower, which allows the outdoor heat exchanger 3 to pass outside air. 9A, 9B and 9C are indoor blowers, which allow indoor air to flow through the indoor heat exchangers 7A, 7B and 7C. A receiver 5 is provided in the liquid refrigerant pipe 12. Reference numeral 17 denotes an accumulator, which is provided on the suction side of the compressor 1.

Reference numeral O denotes an outdoor unit, in which a compressor 1, an outdoor switching valve 18, 2, an outdoor heat exchanger 3, an outdoor blower 16, an outdoor throttle mechanism 4, a receiver 5, an accumulator 17 and the like are provided. It is built in.

A, B, and C are indoor units, and the indoor unit A includes an indoor heat exchanger 7A and an indoor throttling mechanism 6A.
And an indoor blower 9A, etc., and the indoor unit B has an indoor heat exchanger 7B, an indoor throttle mechanism 6B, and an indoor blower.
9B, etc. are built in, and indoor unit C has indoor heat exchanger 7
C, the indoor throttle mechanism 6C, the indoor blower 9C, etc. are built in.

S is a branch unit, in which the branch discharge gas pipes 10A, 10B and 10C, the branch suction gas pipes 11A and 11B,
11C, indoor switching valves 13A, 13B, 13C and 8A, 8B, 8C are built in.

The indoor unit O and the branch unit S are connected to each other through a discharge gas pipe 10, a suction gas pipe 11 and a liquid refrigerant pipe 12, and the branch unit S and a plurality of indoor units A,
B and C are connected refrigerant piping 14A, 14B, 14C, 15A, 15B
, 15C.

The outdoor unit O and the indoor units A, B and C are connected via control signal lines, and the branch unit S and the indoor units A, B and C are connected via control signal lines. , The outdoor switching valves 2, 18 and the indoor switching valves 8A, 8B, 8C, 13 according to the operation modes and loads of the indoor units A, B, C transmitted via these control signal lines.
A, 13B, 13C, outdoor side throttle mechanism 4, indoor side throttle mechanism 6
A, 6B, 6C are opened and closed, and the air volumes of the outdoor blower 16 and the indoor blowers 9A, 9B, 9C are adjusted.

When all or part of the indoor units A, B, C are cooled, for example, when the indoor units A, B are cooled and the indoor unit C is stopped, the outdoor expansion mechanism 4, The indoor throttle mechanisms 6A and 6B have a predetermined opening, and the indoor throttle mechanism 6C is fully closed. And
The outdoor switching valve 18 is opened and the outdoor switching valve 2 is closed so that the outdoor heat exchanger 3 communicates with the discharge gas pipe 10. Indoor side switching valve
The indoor heat exchangers 7A and 7B communicate with the intake gas pipe 11 by opening 8A and 8B and closing the indoor switching valves 13A and 13B. And
The indoor switching valves 13C and 8C are closed.

Then, the refrigerant gas compressed by the compressor 1 passes through the discharge gas pipe 10 and the outdoor switching valve 18, and then the outdoor heat exchanger 3
Then, it radiates heat to the outside air blown by the outdoor blower 16 to be condensed and liquefied to become a liquid refrigerant. Next, this liquid refrigerant passes through the outdoor expansion mechanism 4 and enters the receiver 5, where the gas components are separated.

The liquid refrigerant flowing out of the receiver 5 passes through the liquid refrigerant pipe 12, the connecting refrigerant pipes 14A and 14B, and the indoor side throttle mechanism 6
It enters A and 6B, and when it is squeezed there, it undergoes adiabatic expansion and becomes a gas-liquid two phase. The gas-liquid two-phase refrigerant enters the indoor heat exchangers 7A and 7B, where the indoor air blown by the indoor blowers 9A and 9B is cooled and evaporated and vaporized. This gas refrigerant is connected to refrigerant pipes 15A and 15B, indoor switching valves 8A and 8B, branch suction gas pipes 11A and 11B, suction gas pipe 1
First, it is sucked into the compressor 1 through the accumulator 17.

When all or some of the indoor units A, B, C are operated for heating, for example, when the indoor units A, B are operated for heating and the indoor unit C is stopped, the outdoor expansion mechanism 4, the room The inner throttle mechanisms 6A and 6B are set to a predetermined opening, and the indoor throttle mechanism 6C is fully closed. Then, the outdoor switching valve 18 and the indoor switching valves 8A, 8B, 8C and 13C are closed, and the outdoor switching valve 2 and the indoor switching valves 13A and 13B are opened.

Thus, the gas refrigerant discharged from the compressor 1 passes through the discharge gas pipe 10, the branch discharge gas pipes 10A and 10B, the indoor side switching valves 13A and 13B, the connecting refrigerant pipes 15A and 15B, and the indoor heat exchanger 7A. , 7B to condense and liquefy, indoor side throttle mechanism 6A, 6B
After being squeezed by, the connection refrigerant piping 14A, 14B, liquid refrigerant piping 1
2. Adiabatic expansion is performed by the outdoor throttle mechanism 4 via the receiver 5. Next, after evaporating and vaporizing in the outdoor heat exchanger 3, the outdoor switching valve 2, the suction gas pipe 11, and the accumulator 17 are returned in this order to the compressor 1.

In the simultaneous cooling / heating operation, when the number of indoor units to be cooled is equal to the number of indoor units to be heated, for example, the indoor unit C is in cooling operation,
When the indoor unit A is in the heating operation and the indoor unit B is not operating, the outdoor expansion mechanism 4 is closed and the indoor expansion mechanisms 6A and 6C are used.
Is a predetermined opening, and the indoor throttle mechanism 6B is fully closed. Then, the indoor switching valves 13A, 8C are opened, and the outdoor switching valves 2, 18 and the indoor switching valves 8A, 8B, 13B, 13C are closed.

Thus, the gas refrigerant discharged from the compressor 1 is discharged into the discharge gas pipe 10, the branch discharge gas pipe 10A, and the indoor switching valve.
13A, connecting refrigerant pipe 15A, indoor heat exchanger 7A, indoor throttle mechanism 6A, connecting refrigerant pipe 14A, liquid refrigerant pipe 12, connecting refrigerant pipe 14C, indoor throttle mechanism 6C, indoor heat exchanger 7C, connecting refrigerant Pipe 15C, indoor side switching valve 8C, branch suction gas pipe 11C,
The suction gas pipe 11 and the accumulator 17 are passed in this order to return to the compressor 1.

In the simultaneous cooling / heating operation, when the number of indoor units to be cooled is larger than the number of indoor units to be heated, for example, the indoor units B and C are in cooling operation and the indoor unit A is in heating operation. At the time of opening, the outdoor throttle mechanism 4 and the indoor throttle mechanisms 6A, 6B, 6C are set to predetermined openings. Then, the outdoor switching valve 18 and the indoor switching valves 13A, 8B, 8C are opened, and the outdoor switching valve 2 and the indoor switching valve 8 are opened.
A, 13B and 13C are closed.

Thus, the refrigerant discharged from the compressor 1 is branched by the discharge gas pipe 10, and a part of the refrigerant is passed through the outdoor switching valve 18, the outdoor heat exchanger 3, the outdoor throttling mechanism 4, and the receiver 5 to form a liquid. Enter the refrigerant pipe 12. The balance is the branch discharge gas pipe 10A, the indoor switching valve 13A, the connecting refrigerant pipe 15A, the indoor heat exchanger 7A,
Liquid refrigerant piping via indoor side throttling mechanism 6A and connecting refrigerant piping 14A
Enter 12 and join the previously branched refrigerant. Next, this refrigerant is connected to the refrigerant pipes 14B and 14C and the indoor throttle mechanism 6B and 6C.
C, indoor heat exchangers 7B, 7C, connecting refrigerant pipes 15B, 15C,
The indoor side switching valves 8B, 8C, the branch suction gas pipes 11B, 11C, the suction gas pipe 11, and the accumulator 17 are returned to the compressor 1 in this order.

When the operation of the indoor units during the heating operation is stopped during the simultaneous cooling / heating operation, for example, the indoor units A and B stop the heating operation and the indoor unit C stops the heating operation of the indoor unit A during the cooling operation. Then, the indoor blower 9A of the indoor unit A is stopped and the indoor switching valve 13A is closed. Then, the indoor side switching 13 in which the gas refrigerant is closed
The opening of the indoor throttle mechanism 6A is minimized in order to prevent it from leaking from A and entering the indoor heat exchanger 17A where it is liquefied and accumulated inside.

[0021]

In the conventional air conditioner described above, during the simultaneous cooling and heating operation, that is, as shown in the above example, the indoor units A and B are in the heating operation and the indoor unit C is in operation.
When the heating operation of the indoor unit A is stopped during the cooling operation, the indoor side expansion mechanism 6A is slightly opened, so that the indoor side switching valve 13A leaks and the indoor side heat exchanger 7A.
The high-pressure refrigerant gas that has entered enters the liquid refrigerant pipe 12 through the indoor-side throttling mechanism 6A and flows into the indoor unit C that is in the cooling operation along with the liquid refrigerant that flows through this, and Since the flash is performed, there is a problem that the cooling capacity of the indoor unit C is reduced.

[0022]

SUMMARY OF THE INVENTION The present invention has been invented to solve the above problems, and its gist is to provide a compressor and a discharge gas connected to the discharge side of the compressor. A pipe, a suction gas pipe connected to the suction side of the compressor, an outdoor heat exchanger, and an outdoor side for selectively communicating the gas side of the outdoor heat exchanger with the discharge gas pipe or the suction gas pipe. The switching valve, the outdoor expansion mechanism provided on the liquid side of the outdoor heat exchanger, the plurality of indoor heat exchangers, and the gas side of the plurality of indoor heat exchangers to the discharge gas pipe or suction. An indoor side switching valve that selectively communicates with the gas pipe, an indoor side throttling mechanism provided on each of the liquid sides of the plurality of indoor heat exchangers, a liquid side of the outdoor side throttling mechanism, and the indoor side throttling mechanism. It is equipped with a liquid refrigerant pipe that connects the liquid side of the In a multi-type heat pump type air conditioner that can be operated occasionally, a first solenoid valve that is closed in a heating stop mode during simultaneous cooling and heating operation is provided on the liquid side of the indoor throttle mechanism, and The other end of a bypass pipe, one end of which is connected between the solenoid valve and the indoor throttle mechanism, is connected to the intake gas pipe, and the bypass pipe is opened in a heating stop mode during simultaneous cooling and heating operation. The multi-type heat pump type air conditioner is characterized in that the electromagnetic valve is installed.

[0023]

According to the present invention, during the simultaneous cooling / heating operation, the first solenoid valve of the indoor unit in which the heating operation is stopped is closed and the second solenoid valve is opened. The gas refrigerant that has entered the indoor heat exchanger gradually flows into the intake gas pipe through the indoor throttle mechanism that is slightly open, the bypass pipe, and the second solenoid valve, and therefore flows into the liquid refrigerant pipe. There is nothing to do.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENT One embodiment of the present invention is shown in FIG. The first solenoid valves 21A, 21B, 21C that are closed in the heating stop mode during simultaneous cooling and heating operation are installed on the liquid sides of the indoor side throttle mechanisms 6A, 6B, 6C of the indoor units A, B, C, respectively. Has been done.

Then, the first solenoid valves 21A, 21B, 21
Bypass pipe 22A between C and indoor side throttle mechanism 6A, 6B, 6C
, 22B, 22C are connected to one end, and the other ends are connected to the suction gas pipe 11, respectively. The bypass pipes 22A, 22B and 22C are provided with second solenoid valves 23A, 23B and 23C which are opened in the heating stop mode during the simultaneous cooling and heating operation.

Table 1 shows the relationship between the operation modes of the indoor units A, B and C and the opening / closing of the indoor switching valve, the first solenoid valve, the second solenoid valve and the indoor throttle mechanism 6. There is.

[0027]

[Table 1]

Other configurations are the same as those of the conventional one shown in FIG. 2, and corresponding members are designated by the same reference numerals and the description thereof will be omitted.

However, when the indoor units A and B are in the heating operation and the indoor unit C is in the heating operation while the indoor unit A is in the heating operation is stopped during the simultaneous cooling / heating operation, the indoor side switching valve is operated. The first solenoid valve 21A is closed and the second solenoid valve 23A is opened at the same time when 13A is closed and the opening degree of the indoor throttle mechanism 6A is minimized.

Thus, the refrigerant gas in the discharge gas pipe 10 leaks from the closed outdoor switching valve 13A through the branch discharge gas pipe 10A, passes through the connecting refrigerant pipe 15A, and the indoor heat exchanger 7A.
The air is drawn into the suction gas pipe 11 through the inside throttle mechanism 6A, which is slightly open, the connecting refrigerant pipe 14A, the bypass pipe 22A, and the second solenoid valve 23A.

At this time, since the first solenoid valve 21A is closed, the gas refrigerant does not enter the liquid refrigerant pipe 12 as in the conventional case. As a result, unlike the conventional one, the gas refrigerant is not accompanied by the liquid refrigerant into the indoor unit C during the cooling operation and does not flash there, so that the cooling capacity of the indoor unit C is not reduced.

Since the first solenoid valve 21 is opened and the second solenoid valve 23 is closed during the heating operation of the indoor unit A, the gas refrigerant from the discharge gas pipe 10 is branched to the branch discharge gas pipe 10A and the inside of the room. Switching distributor 13A, connecting refrigerant pipe 15A, indoor heat exchanger
7A, the indoor throttle mechanism 6A, the connecting refrigerant pipe 14A, and the first solenoid valve 21 are passed in this order to enter the liquid refrigerant pipe 12.

Further, during the cooling operation of the indoor unit A,
Since the first solenoid valve 21A is open, the liquid refrigerant pipe 12
Liquid refrigerant from the connection refrigerant pipe 14A, the first solenoid valve 21A,
Outdoor side expansion mechanism 6A, indoor side heat exchanger 7A, connection refrigerant pipe 15
A, the branched intake gas pipe 11A, and the outdoor switching valve 8A are passed in this order to enter the intake gas pipe 11.

Although the operation of the indoor unit A in each operation mode has been described above, the indoor units B and C also operate in the same manner as above.

[0035]

According to the present invention, the first solenoid valve that is closed in the heating stop mode during simultaneous cooling and heating operation is provided on the liquid side of the indoor throttle mechanism, and the first solenoid valve and the room are also provided. The other end of the bypass pipe, one end of which is connected to the inner throttle mechanism, is connected to the intake gas pipe, and a second solenoid valve that opens in the heating stop mode during simultaneous cooling and heating operation is connected to this bypass pipe. As a result, the first solenoid valve of the indoor unit that stopped heating operation closes and the second solenoid valve opens during simultaneous cooling and heating operation, so the indoor side switching valve leaks and indoor heat exchange occurs. The gas refrigerant that has entered the container gradually flows into the suction gas pipe through the indoor throttle mechanism that is slightly open, the bypass pipe, and the second electromagnetic valve, and therefore does not flow into the liquid refrigerant pipe. As a result, since the gas refrigerant does not enter the indoor heat exchanger of the indoor unit during the cooling operation to flush the liquid refrigerant, it is possible to prevent the cooling capacity of the indoor unit during the cooling operation from decreasing.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing an embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram of a conventional air conditioner.

[Explanation of symbols]

 1 compressor 10 discharge gas pipe 11 suction gas pipe O outdoor unit 3 outdoor heat exchanger A, B, C indoor unit 7A, 7B, 7C indoor heat exchanger 12 liquid refrigerant pipe 2, 18 outdoor switching valve 8A, 8B, 8C, 13A, 13B, 13C Indoor side switching valve 4 Outdoor side throttle mechanism 6A, 6B, 6C Indoor side throttle mechanism S Branch unit 10A, 10B, 10C Branch discharge gas pipe 11A, 11B, 11C Branch suction gas pipe 21A, 21B, 21C first solenoid valve 22A, 22B, 22C bypass pipe 23A, 23B, 23C second solenoid valve

Claims (1)

[Claims] 1. A compressor, a discharge gas pipe connected to a discharge side of the compressor, a suction gas pipe connected to a suction side of the compressor, an outdoor heat exchanger, and an outdoor heat exchange of the outdoor compressor. Outdoor switching valve for selectively communicating the gas side of the reactor with the discharge gas pipe or the suction gas pipe, an outdoor throttling mechanism provided on the liquid side of the outdoor heat exchanger, and a plurality of indoor heat exchanges And an indoor side switching valve for selectively communicating the gas side of the plurality of indoor side heat exchangers with the discharge gas pipe or the suction gas pipe, and the liquid side of the plurality of indoor side heat exchangers, respectively. A multi-type capable of performing a cooling operation, a heating operation, and a simultaneous cooling / heating operation, including an indoor throttle mechanism and a liquid refrigerant pipe connecting the liquid side of the outdoor throttle mechanism and the liquid side of the indoor throttle mechanism. In the heat pump type air conditioner, cooling is performed on the liquid side of the indoor throttling mechanism. A first solenoid valve that is closed in the heating stop mode during simultaneous operation of the cells is provided, and the other end of the bypass pipe, one end of which is connected between the first solenoid valve and the indoor throttle mechanism, is connected to the intake gas. A multi-type heat pump type air conditioner, which is connected to a pipe, and a second solenoid valve that is opened in a heating stop mode during simultaneous cooling and heating operation is installed in this bypass pipe.