JPH08240354A - Electrical expansion valve-controlling device for branching device - Google Patents

Abstract

PURPOSE: To provide an electrical expansion valve control device for a branching device capable of recovering all refrigerants without producing any clogged circuit even if an indoor device only other than indoor devices connected to the branching device is operated. CONSTITUTION: Electrical expansion valves 108b1 and 108b2 arranged at a branching device 2 corresponding to an indoor device which is lastly thermo- turned off or stopped in operation out of indoor devices 106b1, 106b2 connected to the branching device 2 are constructed to be fully opened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric expansion valve of a branch unit connected to an air conditioner.

[0002]

2. Description of the Related Art In recent years, a separation type air conditioner has come to take measures to connect a branch unit to an outdoor unit to increase the number of connected indoor units in order to cope with small capacity and multiple rooms. It was

Conventionally, this type of branching unit has generally been constructed as shown in FIG. The configuration will be described below with reference to FIG.

As shown in the drawing, a compressor 102, a four-way valve 103 for switching the flow direction of the refrigerant, an outdoor heat exchanger 104, and electric expansion valves 105a and 105b having a refrigerant throttling mechanism are provided inside the outdoor unit 101. Each indoor unit 106
a or the branch unit 107, and the outdoor heat exchanger 104 and the electric expansion valves 105 a, 1
The liquid side valve 109 is provided between 05b, and the outdoor unit 1
01 and the indoor units 106a, 106b1, 106b2
The gas side valve 110 is provided between the four-way valve 103 and the connection port with
Is provided. On the other hand, the branch unit 107 connected to the electric expansion valve 105b receives the signals from the indoor units 106b1 and 106b2 connected to the branch unit 107, and the electric expansion valve 10 of the branch unit 107 is connected to the branch unit 107.
Electric expansion valve control device 11 for controlling 8b1 and 108b2
1 is provided, and the electric expansion valve control device 111 is connected to the control device 112 of the outdoor unit 101.

When the outdoor unit 101 is operated in the cooling mode by the indoor unit 106b1,
Electric expansion valve 108b corresponding to the indoor unit 106b1
1, 105b are open at a constant opening. On the other hand, thermo O
FF or indoor units 106a, 106 that are stopped
The electric expansion valves 105a and 108b2 corresponding to b2 are fully closed to prevent freezing of the indoor coil. Further, when the indoor unit 106a is in the cooling operation, the electric expansion valve 105 corresponding to the operating indoor unit 106a.
The opening a is a constant opening, and the electric expansion valves 108b1, 108b2, 105b corresponding to the indoor units 106b1, 106b2 that are in the thermo-OFF or stopped state are fully closed.

In the above structure, the outdoor unit 1 is operated during the pump down operation for recovering the refrigerant to the outdoor unit 101 for the relocation of the air conditioner and the expansion of the indoor unit.
After closing the liquid side valve 109 provided in 01,
At least one of the indoor units 106a, 106b1 and 106b2 is operated in the cooling operation for a predetermined time, and then the gas side valve 110 is closed. However, when only the indoor unit 106a that is directly connected to the outdoor unit 101, rather than the branch unit 107, is subjected to the cooling operation and the refrigerant is recovered, the electric expansion valve 105a corresponding to this indoor unit 106a opens at a constant opening, Although the refrigerant is recovered, since the indoor units 106b1 and 106b2 connected to the branch unit 107 are in a stopped state, the electric expansion valve 108 provided in the branch unit 107
The electric expansion valves 105b provided in b1 and 108b2 and the outdoor unit 101 are fully closed. For this reason, the refrigerant in the pipe between the electric expansion valves 108b1, 108b2, 105b is blocked and remains without being recovered, so that at least one of the indoor units connected to the branch unit 107 operates. It will be.

[0007]

In the conventional electric expansion valve control device for the branch unit, the branch unit 10 is used.
Since 7 is usually installed behind the ceiling, it cannot be determined which indoor unit is connected to the branch unit 107,
When performing the pump down operation, all the indoor units 106a, 106b1, 106b2 had to be operated, and the pump down operation was complicated and many mistakes were made.

The present invention is to solve the above problems and provides a control device for an electric expansion valve of a branch unit capable of recovering a refrigerant even when only one indoor unit connected to a unit other than the branch unit is operated during pump down operation. The purpose is to provide.

[0009]

In order to achieve the above object, an electric expansion valve control device for a branch unit according to the present invention has a first structure.
Is connected to the outdoor unit on one side,
An electric expansion valve corresponding to the connected indoor unit is provided in the branch unit connected to the other indoor units, and an electric expansion valve of the branch unit is generated by a signal from the indoor unit connected to the branch unit. In addition, the opening of the electric expansion valve corresponding to the indoor unit finally stopped or thermo-OFF among the indoor units connected to the branch unit is fully opened or a constant opening is opened.

The second means is that when the indoor units connected to the branch unit are all stopped or turned off, the opening degree of all the electric expansion valves provided in the branch unit after a certain time has elapsed. , Or fully open or open a certain degree.

[0011]

The present invention has the structure of the above-mentioned first means.
Even if all the indoor units connected to the branch unit are thermo-OFF or stopped, at least one of the electric expansion valves in the branch unit is opened and does not become a closed circuit, so it is not an indoor unit connected to the branch unit. It is possible to perform the pump down operation by operating only the indoor unit.

Further, according to the structure of the second means, when all the indoor units connected to the branch unit are stopped or the thermostat is turned off, the electric expansion valves in the branch unit are all opened at a constant opening after a certain period of time. Since the closed circuit is not formed, the pump down operation can be performed even when only the indoor units other than the indoor unit connected to the branch unit are operated.

[0013]

【Example】

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. The operation chart is shown in FIG.

The same parts as those of the conventional example are designated by the same reference numerals and detailed description thereof will be omitted. As shown in the figure, the branch unit 2 connected to the electric expansion valve 105b includes indoor units 106b1 and 1b1 connected to the branch unit 2.
An electric expansion valve control device 1 for controlling the electric expansion valves 108b1 and 108b2 of the branch unit 2 is provided by a signal from 06b2, and the electric expansion valve control device 1 is connected to the control device 112 of the outdoor unit 101. .

When the indoor unit 106b1 connected to the branch unit 2 is stopped, the branch unit 2
When the other indoor unit 106b2 connected to is operating, the electric expansion valve 108b1 in the branch unit 2 is fully closed, and the electric expansion valve 108b2 and the outdoor unit 101 corresponding to the operating indoor unit 106b2.
The electric expansion valve 105b has an opening degree according to the operation of the indoor unit 106b2.

Further, when the indoor unit 106b2 stops, the indoor unit 106 connected to the branch unit 2
b1 and 106b2 are all stopped, and the electric expansion valve 1 corresponding to the indoor unit 106b2 that stopped last
08b2 is fully opened. On the other hand, the electric expansion valve 105b provided in the outdoor unit 101 is fully closed.

In the above structure, when the pump down operation for recovering the refrigerant in the outdoor unit 101 is performed due to the relocation of the air conditioner and the expansion of the indoor unit, the liquid side valve 109 provided in the outdoor unit 101 is closed. Then, the indoor units 106a, 106b1, 106
At least one of b2 is operated in the cooling operation for a predetermined time, and then the gas side valve 110 is closed.

As described above, according to the electric expansion valve control device for the branch unit of the first embodiment of the present invention, one electric expansion valve provided in the branch unit is always open, and the refrigerant can be reliably recovered. Becomes (Second Embodiment) A second embodiment of the present invention will be described below with reference to FIG. 3 showing an operation chart.

The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. As shown in the figure, the branch unit 2 connected to the electric expansion valve 105b includes an indoor unit 106b connected to the branch unit 2.
This branching unit 2 is operated by the signal from 1, 106b2.
The electric expansion valve control device 1 for controlling the electric expansion valves 108b1 and 108b2 is provided.
Is connected to the control device 112 of the outdoor unit 101. When another indoor unit 106b2 connected to the branch unit 2 is operating when the indoor unit 106b1 connected to the branch unit 2 is stopped,
The electric expansion valve 108b1 in the branch unit 2 is fully closed, and the electric expansion valve 108b2 corresponding to the operating indoor unit 106b2 and the electric expansion valve 105b of the outdoor unit 101 are opened according to the operation of the indoor unit 106b2. . Further, when the indoor unit 106b2 stops, the indoor unit 106 connected to the branch unit 2
All of b1 and 106b2 are stopped. At this time, in order to prevent gas noise from being generated in the stopped indoor unit 106b1, the electric expansion valves 108b1 and 108b2 provided in the branch unit 2 after a certain time has passed.
Are all fully open. On the other hand, the electric expansion valve 105b provided in the outdoor unit 101 and corresponding to the branch unit 2 includes the indoor units 106b1 and 106b connected to the branch unit 2.
It is fully closed because all b2 are stopped.

In the above structure, when the refrigerant is collected in the outdoor unit 101 for the relocation of the air conditioner and the expansion of the indoor unit, the liquid side valve 109 provided in the outdoor unit 101 is closed and then the indoor unit is closed. 106
a, 106b1 and 106b2, at least one of them is operated in a cooling operation for a predetermined time, and then the gas side valve 110
Will be closed.

As described above, according to the electric expansion valve control device for the branch unit of the second embodiment of the present invention, when all the indoor units connected to the branch unit are stopped, they are provided in the branch unit. Further, the electric expansion valve is fully opened after a certain period of time, and the refrigerant can be surely recovered.

[0022]

As is apparent from the above embodiments, according to the present invention, since one electric expansion valve in the branch unit is always open, the liquid side valve in the outdoor unit is recovered for refrigerant recovery. Even if the indoor units other than the indoor unit connected to the branch unit are cooled after being closed, the refrigerant between the indoor unit and the branch unit will also be recovered by the outdoor unit through the open electric expansion valve. It is possible to provide an electric expansion valve control device for a branch unit that can perform refrigerant recovery regardless of which indoor unit is operated and can easily perform pump down operation.

Further, since at least one of the electric expansion valves provided in the branch unit is opened, there is an effect of preventing a blocking circuit such as a liquid ring between the branch unit and the outdoor unit.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of an electric expansion valve control device for a branch unit according to a first embodiment of the present invention.

FIG. 2 is an operation chart of the electric expansion valve control device for the branch unit according to the first embodiment.

FIG. 3 is an operation chart of the electric expansion valve control device for the branch unit according to the second embodiment.

FIG. 4 is a refrigeration cycle diagram of a conventional electric expansion valve control device for a branch unit.

[Explanation of symbols]

 1 Electric Expansion Valve Control Device 2 Branch Unit 101 Outdoor Unit 105b Electric Expansion Valve 106a Indoor Unit 106b1 Indoor Unit 106b2 Indoor Unit 108b1 Electric Expansion Valve 108b2 Electric Expansion Valve

Claims (2)

[Claims] 1. A branch unit, one of which is connected to an outdoor unit and the other of which is connected to a plurality of indoor units, is provided with an electric expansion valve corresponding to the connected indoor unit, and is connected to the branch unit. The signal from the indoor unit is used to control the electric expansion valve of the branch unit, and also to open the electric expansion valve corresponding to the indoor unit connected to the branch unit that is stopped or turned off. The electric expansion valve control device of the branch unit, which is configured to be fully opened or open a certain degree. 2. When the indoor units connected to the branch unit are all stopped or turned off, the opening degrees of all the electric expansion valves provided in the branch unit are
2. The electric expansion valve control device for a branch unit according to claim 1, wherein the electric expansion valve control device is configured to be fully opened or opened at a constant opening after a predetermined time has elapsed.