JP2002235964A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner, in which positioning of a four-way valve in an outdoor unit can be substantially positively performed so long as the valve has no malfunction. SOLUTION: The air conditioner is provided with a plurality of outdoor units A-C having respectively four-way valves A1-C1, and a centralized controller for controlling positioning of the four-way valve. In the control, the outdoor units A-C are successively operated, and positions of respective four-way valves are selected in the direction corresponding to the operation mode. The units A-C transmit signals respectively to the centralized control device whether respective valve positions have been switched in the direction corresponding to the operation mode. If the controller does not receive signals of successful valve-switching from either of the outdoor units in a predetermined time, the operation is suspended, and the valve positioning control is repeated. The air conditioner is further provided with a control means, which gives priority in starting the next valve positioning to an outdoor unit C having failed in the switching in the previous control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in which a plurality of outdoor units are connected in parallel to an interunit pipe extending from an indoor unit.

[0002]

2. Description of the Related Art In general, an air conditioner including a plurality of outdoor units having a four-way valve is known. In this type, each outdoor unit may be controlled using a central control unit (hereinafter, referred to as CCU).

In this control, when the CCU performs the four-way valve alignment control, all the outdoor units are sequentially operated, and the positions of the four-way valves are switched in a direction corresponding to the operation mode. The CCU transmits whether or not the position of its own four-way valve has switched in the direction corresponding to the operation mode, and this CCU does not receive a success of switching the position of the four-way valve from all the outdoor units within a predetermined time (for example, 2 minutes). In this case, the operation is temporarily stopped, and the four-way valve adjustment control is executed again.

[0004]

In performing the above four-way valve adjustment control, when the number of outdoor units is large, starting all of the outdoor units at once increases the starting current. The outdoor units are activated sequentially.

Therefore, it takes time to determine the switching of the four-way valve position in all the outdoor units, and for example, there is a possibility that the determination cannot be made within two minutes. In this state, no matter how many times the four-way valve control is executed, there is a high possibility that the control will fail.

It is conceivable to extend the above-mentioned predetermined time. However, if the predetermined time is extended, even if switching of the four-way valve is unsuccessful, the operation continues for a long time, so that high-pressure refrigerant flows into another outdoor unit. Problem.

[0007] Therefore, an object of the present invention is to solve the problems of the prior art and to provide an air conditioner which can almost certainly perform the positioning of the four-way valve of the outdoor unit unless the four-way valve has a problem. To provide.

[0008]

According to the first aspect of the present invention,
When a plurality of outdoor units having a four-way valve are provided and the four-way valve alignment control is performed, all the outdoor units are sequentially operated and the positions of the four-way valves are switched in a direction coinciding with the operation mode, and all the outdoor units are operated. If the switching of the position of the four-way valve is not successful within the predetermined time, in an air conditioner that temporarily stops operation and executes the four-way valve adjustment control again, the position of the four-way valve is switched by the previous four-way valve adjustment control. Control means for starting the failed outdoor unit preferentially in the next four-way valve adjustment control is provided.

According to a second aspect of the present invention, when a plurality of outdoor units each having a four-way valve are provided, and when the central control unit performs the four-way valve alignment control, all the outdoor units are sequentially operated to coincide with this operation mode. The position of each four-way valve is switched in the direction, and each outdoor unit transmits to the central control unit whether or not the position of its own four-way valve has been switched in the direction corresponding to the operation mode, and this central control unit within a predetermined time If the success of switching the position of the four-way valve is not received from all the outdoor units, in the air conditioner that temporarily stops operation and executes the four-way valve alignment control again, the position of the four-way valve is switched in the previous four-way valve alignment control. The control unit is provided with a control unit that preferentially starts the outdoor unit that failed in the next four-way valve alignment control.

According to the present invention, the outdoor unit which failed to switch the position of the four-way valve in the previous four-way valve alignment control,
Since the next four-way valve control is started with priority, the four-way valve alignment of the previously failed outdoor unit can be almost surely succeeded unless the four-way valve is defective.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numerals 1A and 1B denote outdoor units. These outdoor units 1A and 1B are connected in parallel to an inter-unit pipe 9 composed of a gas pipe 5 and a liquid pipe 7 connected to the indoor units 3A to 3D.

The outdoor units 1A and 1B include compressors 11A and 11B driven by gas engines, oil separators 12A and 12B, four-way valves 13A and 13B, outdoor heat exchangers 14A and 14B, outdoor fans 17A and 17B, expansion valves. 1
5A, 15B, and other accumulators 16A, 16B. In addition, indoor units 3A-3
D is the indoor heat exchangers 34A to 34D, the indoor fan 37A
To 37D and indoor electric expansion valves 39A to 39D.

In this embodiment, a central control unit (hereinafter referred to as C
It is called CU. ) 100, each outdoor unit 1A,
1B is controlled.

During the heating operation, the four-way valves 13A and 13B are switched to the state indicated by the dotted lines. The refrigerant from the compressors 11A and 11B is supplied to the oil separator 1 as indicated by the dotted arrows.
After passing through 2A, 12B and four-way valves 13A, 13B, they enter the branch gas pipes 5A, 5B, join the gas pipes 5, and flow into the indoor units 3A to 3D. Indoor heat exchangers 34A-34
D, through the indoor electric expansion valves 39A to 39D, merges with the liquid pipe 7, passes through the receiver tank 33, and
Enter A, 1B. The air is returned to the suction pipes of the compressors 11A and 11B via the outdoor heat exchangers 14A and 14B, the four-way valves 13A and 13B, and the accumulators 16A and 16B.

During the cooling operation, the four-way valves 13A and 13B are switched to the solid line state. The refrigerant from the compressors 11A and 11B is supplied to the oil separator 1 as indicated by solid arrows.
After passing through 2A, 12B and four-way valves 13A, 13B, they enter the outdoor heat exchangers 14A, 14B, and reach the liquid pipe 7 and the receiver tank 33 through expansion valves 15A, 15B. From there, it enters the indoor units 3A to 3D, and the indoor electric expansion valve 39A
Through the indoor heat exchangers 34A-34D, enter the gas pipe 5, and the branch gas pipes 5A and 5B.
A, 1B four-way valves 13A, 13B, accumulator 16
A and 16B are returned to the suction pipes of the compressors 11A and 11B.

In the above air conditioner, the four-way valves 1 of all the outdoor units 1A, 1B are operated during the operation of the system regardless of whether the individual outdoor units 1A, 1B are operated or stopped.
It is necessary to match the switching position of 3A, 13B with the operation mode. For example, in the heating operation mode,
The switching position of each of the four-way valves 13A and 13B is matched with the dotted line state.
It is necessary to match the switching position of 3B with the solid line state.

This four-way valve adjustment control is based on the CCU described above.
100 executes. When the CCU 100 is operated for the first time after the system is initialized, or when the switching of the air conditioning is performed, all the outdoor units 1A, 1
The operation of B is stopped, and the four-way valve adjustment control is executed in the following procedure.

FIG. 2 is a time chart showing the procedure of the four-way valve adjustment control. In FIG. 1, two outdoor units are described. However, for convenience of explanation, three outdoor units are used, A, B, and C are attached to each outdoor unit, and A1, B1 are assigned to the four-way valves. , C1.

In FIG. 2A, when the four-way valve adjustment control is turned on by a command from the CCU 100, first, the outdoor unit A starts in FIG. 2B, and a little later, the outdoor unit B starts in FIG. 2C. With a delay, the outdoor unit C is activated in FIG. 2d. This is for minimizing the starting current.

In FIG. 2b, after the outdoor unit A is activated,
First, in FIG. 2e, the four-way valve A1 is switched in a direction corresponding to the operation mode in this case. As long as no inconvenience occurs in the four-way valve A1, if a positioning signal is output from the CCU 100, the four-way valve A1
1 switches in the direction corresponding to the operation mode. Whether or not this has been switched is determined by, for example, the outdoor heat exchanger 14A, 1
The temperature is detected by the temperature rise of the refrigerant flowing through the 4B, the gas pipe 5, the liquid pipe 7, and the like, and is transmitted from each of the outdoor units A to C to the CCU 100.

Next, the outdoor unit B is activated in FIG. 2C, and the four-way valve B1 is switched in the direction corresponding to the operation mode in this case in FIG. 2F. Further, FIG.
, The outdoor unit C is activated, and finally, in FIG. 2g, the four-way valve C1 should be switched in a direction corresponding to the operating mode in this case.

However, in FIG. 2A, the time required for one four-way valve adjustment control is set to a maximum of 2 minutes. Therefore, in FIG. 2g, before the four-way valve C1 is switched,
Two minutes have elapsed, and the switching operation of the four-way valve C1 ends in failure without performing the switching operation. Then, after temporarily stopping all the outdoor units, the CCU 100 shifts to the second four-way valve adjustment control. Conventionally, when shifting to the second four-way valve adjustment control,
The same control switching is repeated from the beginning in the order of the outdoor units A to C. This is the same thing, and again,
It is highly likely that the last four-way valve C1 will fail to switch.

In the present embodiment, when executing the second four-way valve adjustment control in FIG. 2A, as shown in FIG. 2D,
The outdoor unit C that failed to switch in the first four-way valve adjustment control is preferentially started. As a result, as shown in FIG. 2g, the four-way valve C1 is switched in a direction corresponding to the operation mode, and the four-way valve adjustment of all the outdoor units A to C is completed at the same time as the first time. According to this,
Since the outdoor unit that failed to switch the last time is preferentially started in the next four-way valve control, the four-way valve alignment that failed last time is almost completed within a maximum of two minutes unless there is a malfunction in the four-way valve. You can be sure of success.

Although the present invention has been described based on one embodiment, it is apparent that the present invention is not limited to this.

[0026]

According to the present invention, the outdoor unit that has failed to switch the last time is preferentially started in the next four-way valve control, so that the four-way valve alignment that failed last time is almost performed unless the four-way valve is defective. It can be executed reliably.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing an embodiment of an air conditioner according to the present invention.

FIGS. 2A to 2G are time charts of four-way valve adjustment control.

[Explanation of symbols]

 1A, 1B Outdoor unit 3A-3D Indoor unit 5 Gas pipe 7 Liquid pipe 11A, 11B Compressor 13A, 13B Four-way valve 100 CCU (Central control unit)

Continuing on the front page (72) Inventor Yoshito Tajima 1 Otsukicho, Ashikaga, Tochigi Prefecture Sanyo Electric Air Conditioning Co., Ltd. (72) Inventor Kazunobu Okawa 1 Otsukicho, Ashikaga City, Tochigi Pref. 72) Inventor Yoshiro Goto 1 Otsukicho, Ashikaga City, Tochigi Prefecture Sanyo Electric Air Conditioning Co., Ltd. (72) Inventor Junji Matsue 1 Otsukimachi, Ashikaga City, Tochigi Prefecture Sanyo Electric Air Conditioning Co., Ltd. F-term (reference) AA01 DD07 EE10 3L092 AA14 BA26 DA06 FA22

Claims (2)

[Claims] When a plurality of outdoor units each having a four-way valve are provided and four-way valve alignment control is performed, all the outdoor units are sequentially operated to switch the position of each four-way valve in a direction coinciding with the operation mode. If the switching of the positions of the four-way valves of all the outdoor units does not succeed within a predetermined time, in an air conditioner that temporarily stops operation and executes the four-way valve adjustment control again, An air conditioner comprising: a control unit that preferentially starts an outdoor unit that failed to switch the position in the next four-way valve adjustment control. 2. When a plurality of outdoor units each having a four-way valve are provided, and when the central control device performs the four-way valve alignment control, all the outdoor units are sequentially operated so that each of the four-way valves is operated in a direction coinciding with the operation mode. The position is switched, and each outdoor unit transmits to the central controller whether or not the position of its own four-way valve has been switched in a direction corresponding to the operation mode, and the central controller transmits the four-way valve from all outdoor units within a predetermined time. If the success of the switching of the valve position is not received, in the air conditioner that temporarily stops the operation and executes the four-way valve adjustment control again, the outdoor unit that failed to switch the position of the four-way valve in the previous four-way valve adjustment control is removed. An air conditioner comprising a control unit that starts up preferentially in the next four-way valve adjustment control.