KR20060062770A - Multi airconditioning system and method for controlling the system - Google Patents

Abstract

The present invention relates to a multi-air conditioning system, and more particularly, to provide a multi-air conditioning system and a control method thereof capable of recovering a refrigerant when a predetermined outdoor unit of a plurality of outdoor units has failed.

To this end, the present invention, a plurality of outdoor units (10, 20, 30); A pressure difference releasing tube (40) installed to connect the refrigerant passages of the outdoor units to each other to solve the refrigerant pressure difference between the outdoor units; Pressure relief valves (51, 52, 53) installed at portions connected to the outdoor units of the pressure difference elimination pipes and automatically opened and closed by a controller; In addition, each of the refrigerant pipes connecting the outdoor unit and the indoor unit is installed so as to block the flow of the refrigerant, respectively, and provides a multi air conditioning system comprising a refrigerant shut-off valve (61 ~ 66) automatically opened and closed by the control unit do.

Multi air conditioning system

Description

Multi air conditioning system and method for controlling the system

1 is a block diagram showing a multi-air conditioning system according to the present invention.

2 is a block diagram showing a refrigerant recovery operation of the multi-air conditioning system of FIG.

Explanation of symbols on the main parts of the drawings

10: main unit 20, 30: sub unit

11, 21, 31: Compression unit 12, 22, 32: Pressure sensor

13,23,33: outdoor heat exchanger 40: pressure difference releasing pipe

51,52,53: Pressure relief valve 61,62,63: Refrigerant shutoff valve

The present invention relates to a multi air conditioning system, and more particularly, to a multi air conditioning system and a control method thereof for improving air conditioning performance.

In general, an air conditioning system is a device that cools and / or heats an indoor space by performing a process of compressing, condensing, expanding, and evaporating a refrigerant. Such an air conditioning system is classified into a cooling system that operates only one direction of the refrigerant cycle to supply only cold air to the room, and a cooling and heating system that selectively supplies the refrigerant cycle in both directions to supply the indoor air or warm air. In addition, it is divided into a general air conditioning system in which one indoor unit is connected to an outdoor unit, and a multi air conditioning system in which a plurality of indoor units are connected to an outdoor unit. In addition, the multi-air conditioning system is divided into one outdoor unit or a plurality of outdoor units.

In the multi-air conditioning system having a plurality of outdoor units, at least one compressor is installed in each outdoor unit. In this case, a constant speed compressor having a constant operating frequency may be used as the compressor, or an inverter compressor having a variable operating frequency may be used.

The multi-air conditioning system having a plurality of outdoor units appropriately adjusts the number of operation of the outdoor unit according to the number of indoor units that are operated.

However, the multi-air conditioning system having a plurality of outdoor units described above has the following problems.

First, when a predetermined outdoor unit of the plurality of outdoor units is broken and replaced, the refrigerant is removed from the system and then replaced, such as welding and sealing. However, since all of the extracted refrigerant has to be discarded, there is a problem that the refrigerant is wasted. In addition, the refrigerant such as freon gas has a problem causing environmental problems, such as destroying the ozone layer.

Second, even if the recovery with the refrigerant recovery device is cumbersome, work efficiency in the field is low, there was a problem that the replacement time and replacement cost increases.

In order to solve the above problems, it is an object of the present invention to provide a multi-air conditioning system and a control method that can recover the refrigerant from the failed outdoor unit.

Another object of the present invention is to provide a multi-air conditioning system and a method of controlling the same, which prevents causing environmental problems.

In order to solve the above problems, the present invention, a plurality of outdoor unit; A pressure difference elimination pipe installed to connect the refrigerant passages of the outdoor units to each other to solve the refrigerant pressure difference between the outdoor units; A pressure relief valve installed at a portion connected to each outdoor unit of the pressure difference relief tube and automatically opened and closed by a controller; In addition, it is provided to each of the refrigerant pipes connecting the outdoor unit and the indoor unit to provide a multi-air conditioning system, each of which is installed so as to block the flow of the refrigerant, and comprises a refrigerant blocking valve automatically opened and closed by the control unit.

The plurality of outdoor units include one main unit including an inverter compressor having a variable operating frequency, and at least one sub unit including at least one constant speed compressor having a fixed fixed operating frequency.

At this time, the pressure difference elimination pipe is preferably connected to the refrigerant pipe between the compressor and the outdoor heat exchanger of each outdoor unit.

According to the present invention, when it is determined that a predetermined outdoor unit has failed, the refrigerant shutoff valves of the failed outdoor unit are closed to prevent the flow of refrigerant from flowing into the high outdoor unit. The present invention provides a control method of a multi-air conditioning system for opening a pressure relief valve of the failed outdoor unit to recover refrigerant.

At this time, it is preferable to operate in the heating mode so that a low pressure is formed on the outdoor unit that is operating than the outdoor unit side that has failed the pressure difference elimination pipe.

Therefore, according to the present invention, the refrigerant can be recovered from the malfunctioning outdoor unit, and it can be prevented from causing an environmental problem.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

Referring to Figure 1, an embodiment of a multi-air conditioning system according to the present invention will be described.

The multi-air conditioning system includes a plurality of outdoor units (10, 20, 30), a pressure difference elimination pipe (40) installed to connect the refrigerant passages of the outdoor units to each other to eliminate the refrigerant pressure difference between the outdoor units, Pressure relief valves (51, 52, 53) which are installed in the portion connected to each outdoor unit of the pressure difference elimination pipe, and automatically opened and closed by a control unit, and the refrigerant flow to the refrigerant pipe connecting each outdoor unit and the indoor unit It is installed so as to block each, and comprises a refrigerant blocking valve (61 ~ 66) that is automatically opened and closed by the control unit.

The plurality of outdoor units includes a main unit 10 including an inverter compressor having a variable operating frequency, and at least one sub unit 20 and 30 including at least one constant speed compressor having a fixed fixed operating frequency. It is configured by.

In this case, the main unit 10 includes a compression unit 11 composed of at least one compressor and an outdoor heat exchanger 13 connected to the compression unit. The compression unit 11 is composed of an inverter compressor. Of course, it is also understood that the compression unit may consist of an inverter compressor and a constant speed compressor. When the inverter compressor alone is configured, the amount of refrigerant and the temperature of the refrigerant can be finely adjusted. In addition, the number of compressors constituting the compression unit can be variously changed. In addition, although one outdoor heat exchanger is shown, it is also understood that two or more may be installed.

The sub units 20 and 30, like the main unit 10, are composed of a compression unit 21 and 31 and an outdoor heat exchanger 23 and 33. However, the compression units 21 and 31 of the sub unit 20 and 30 consist only of a constant speed compressor. Therefore, the main unit 10 can finely control the amount of refrigerant, whereas the sub units 20 and 30 cannot finely control the amount of refrigerant. This sub unit may be different from the configuration of the main unit. For example, it is also possible to change the number of constant speed compressors or the number of outdoor heat exchangers.

In addition, the main unit 10 and the two sub units 20 and 30 are connected to each other by a pressure difference elimination pipe 40. At this time, the branched one end of the pressure difference elimination pipe 40 is preferably connected to the refrigerant pipe between the compression unit (11, 21, 31) and the outdoor heat exchanger (13, 23, 33).

The branched portion of the pressure difference elimination pipe 40 is provided with pressure relief valves (51, 52, 53). At this time, the pressure relief valve is automatically opened and closed by the control unit. These pressure relief valves propose solenoid valves that can be opened and closed automatically as power is supplied.

In addition, refrigerant blocking valves 61 to 66 are respectively installed in the refrigerant pipes connecting the main and sub units 10, 20, 30 and an indoor unit (not shown). The refrigerant blocking valve also presents a solenoid valve that is automatically opened and closed by the control unit.

In addition, pressure sensors 12, 22, and 32 are installed in the refrigerant pipes of the main unit 10 and the sub units 20 and 30. The pressure sensor is also connected to the control unit to determine the failure of the compressor. Of course, it is also understood that failure of the compressor or the like can be determined by various sensors of each main and sub unit.

Referring to the operation of the above-described multi-air conditioning system as follows.

Referring to Figure 1, the heating operation will be described.

The control unit determines the number of operations of the indoor unit and the amount of refrigerant required to operate the predetermined number of sub units and the main unit together.

The refrigerant compressed in the compression unit 11 of the main unit 10 is introduced into an indoor unit (not shown) through one open refrigerant blocking valve 62. At the same time, the refrigerant compressed in the compression units 21 and 31 of the sub units 20 and 30 is introduced into an indoor unit (not shown) through one open refrigerant blocking valve 64 and 66.

The refrigerant of the indoor unit is introduced into the main unit 10 and the sub units 20 and 30 after heat exchange with the indoor air. At this time, the refrigerant is heat-exchanged in the outdoor heat exchanger (13, 23, 33), and then flows back into the compression unit (11, 21, 31) of the main unit 10 and the sub unit (20, 30).

At this time, a predetermined pressure difference is formed in the refrigerant pipe of the main unit 10 and the sub units 20 and 30. When a pressure difference is generated in this way, the refrigerant on the high pressure side flows to the low pressure side through the pressure difference elimination pipe 40. By the flow of the refrigerant, the pressure difference generated between the main unit 10 and the sub units 20 and 30 is eliminated.

Since the cooling operation is performed in the reverse order of the above-described heating operation and the refrigerant flow, the cooling operation will be omitted.

The pressure difference elimination pipe 40 eliminates the pressure difference between the main unit 10 and the sub units 20 and 30 during heating and cooling. During such cooling and heating operation, a failure occurs in the sub unit, such as the compressor reaching the end of its service life. At this time, the above-described multi-air conditioning system performs a refrigerant recovery operation by itself.

Referring to Figure 2, the refrigerant recovery operation will be described.

Each of the pressure sensors 12, 22, and 32 transmits information on the pressure of the refrigerant pipe to the controller, and the controller determines whether there is a failure by comparing the information with a preset pressure range.

When the control unit determines that the compression unit 21 of the predetermined sub unit 20 is broken, all of the refrigerant blocking valves 63 and 64 of the failed sub unit 20 are closed. In addition, the refrigerant blocking valves 61, 62, 65 and 66 of the sub unit and the main unit which are not broken are opened. As a result, the flow refrigerant in the system does not enter the failed subunit. In FIG. 2, when the refrigerant shutoff valve is closed, it is displayed in black, and when the refrigerant shutoff valve is opened, it is marked as empty.

In addition, the pressure relief valve 52 of the failed sub-unit 20 is opened. At this time, the sub unit 30 and the main unit 10 which are not broken are preferably heated. When the heating operation is performed in this way, the pressure difference elimination pipe 40 is formed with a lower pressure than the failed sub-unit 20. This is because the pressure difference elimination pipe 40 is connected to the low pressure side of the sub unit 30 and the main unit 10 that are in operation (between the compression unit and the outdoor heat exchanger). Therefore, the refrigerant in the compression unit 21 and the outdoor heat exchanger 22 of the failed sub-unit is discharged through the pressure relief valve 52, and the refrigerant discharged in this way is operated in the sub unit 30 and the main unit ( 10) is recovered.

When it is determined that the refrigerant recovery operation is completed, the multi air conditioning system is completely turned off. Subsequently, it is necessary to replace the failed subunit or to replace only the compression unit.

The multi-air conditioning system and control method according to the present invention as described above has the following effects.

First, when a predetermined outdoor unit of the plurality of outdoor units is broken, the refrigerant in the failed outdoor unit is recovered to the outdoor unit that has not failed, so that the refrigerant does not need to be wasted as in the prior art, and thus the environmental problems caused by the refrigerant can be solved. .

Second, since there is no need to use a separate refrigerant recovery device for the replacement work, the work efficiency in the field is increased, the replacement time and the replacement cost is reduced.

Claims (5)

A plurality of outdoor units; A pressure difference elimination pipe installed to connect the refrigerant passages of the outdoor units to each other to solve the refrigerant pressure difference between the outdoor units; A pressure relief valve installed at a portion connected to each outdoor unit of the pressure difference relief tube and automatically opened and closed by a controller; And, And a refrigerant blocking valve installed in each of the refrigerant pipes connecting the outdoor units and the indoor units to block the flow of the refrigerant, the refrigerant blocking valve being automatically opened and closed by a controller. The method of claim 1, The plurality of outdoor units are: One main unit including an inverter compressor having a variable operating frequency; And, And at least one subunit comprising at least one constant speed compressor having a fixed operating frequency. The method of claim 2, The pressure difference elimination pipe is a multi-air conditioning system, characterized in that connected to the refrigerant pipe between the compressor and the outdoor heat exchanger of each outdoor unit. If it is determined that the predetermined outdoor unit has failed, Close all refrigerant shutoff valves of the failed outdoor unit to block the flow of the refrigerant flow into the failed outdoor unit, The control method of claim 1, wherein the pressure relief valve of the failed outdoor unit is opened to recover the refrigerant in the failed outdoor unit through the pressure difference elimination pipe. The method of claim 4, wherein The control method of the multi-air conditioning system, characterized in that the operation in the heating mode so that the low pressure is formed on the outdoor unit side operating than the faulty outdoor unit side of the pressure difference elimination pipe.

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