KR102374370B1 - Air conditioning system - Google Patents

Abstract

An air conditioning system according to an embodiment of the present invention includes: a cooling cycle including a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger; an outdoor unit in which the compressor, the outdoor heat exchanger and the expansion mechanism are disposed, the outdoor unit having a high-pressure service valve and a low-pressure service valve; an indoor unit in which the indoor heat exchanger is disposed; a high-pressure on-off valve disposed between the outdoor heat exchanger and the high-pressure service valve during the cooling cycle; a low pressure on/off valve disposed between the low pressure service valve and the compressor during the cooling cycle; a pressure sensor installed in the cooling cycle and measuring the pressure of the refrigerant; and a controller receiving the pressure measured by the pressure sensor and controlling the compressor, the high-pressure on-off valve, and the low-pressure on-off valve.

Description

Air conditioning system {AIR CONDITIONING SYSTEM}

The present invention relates to an air conditioning system, and more particularly, to an air conditioning system capable of pumping down.

In general, an air conditioner is a device that is arranged in a space such as a room, a living room, an office, or a business store to maintain a comfortable indoor environment by controlling the temperature, humidity, cleanliness, and airflow of air.

The air conditioner may perform an air conditioning function by circulating a refrigerant according to a cooling cycle including a compressor, a condenser, an expansion valve, and an evaporator. That is, the refrigerant is present inside the air conditioner, and the risk of the refrigerant leaking is low in normal times.

However, when the air conditioner is previously installed, since the outdoor unit and the indoor unit of the air conditioner are separated and moved, the refrigerant in the air conditioner may leak. To prevent such refrigerant leakage, a refrigerant pump down is performed.

Refrigerant pump-down refers to the operation of collecting and recovering refrigerant in the outdoor unit, the indoor unit, and the pipe when the air conditioner is previously installed in the outdoor unit or the indoor unit. In the case of home air conditioners, it is common to collect the refrigerant toward the outdoor unit.

In the case of the conventional air conditioner, in order to perform refrigerant pump-down, the user had to connect a pressure gauge to the service valve of the outdoor unit prior to refrigerant pump-down. In more detail, the user had to unscrew the high-pressure cap and the low-pressure cap, close the low-pressure service valve, connect the pressure gauge to the low-pressure service valve, and then open the low-pressure service valve again, and then perform refrigerant pump-down.

In addition, since the user has to open and close the service valve directly at the start and completion of the refrigerant pump-down, it is cumbersome, and there is a fear that the user confuses the high-pressure service valve and the low-pressure service valve.

An object of the present invention is to provide an air conditioning system capable of automatically performing refrigerant pump-down.

An air conditioning system according to an embodiment of the present invention includes: a cooling cycle including a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger; an outdoor unit in which the compressor, the outdoor heat exchanger and the expansion mechanism are disposed, the outdoor unit having a high-pressure service valve and a low-pressure service valve; an indoor unit in which the indoor heat exchanger is disposed; a high-pressure on-off valve disposed between the outdoor heat exchanger and the high-pressure service valve during the cooling cycle; a low pressure on/off valve disposed between the low pressure service valve and the compressor during the cooling cycle; a pressure sensor installed in the cooling cycle and measuring the pressure of the refrigerant; and a controller receiving the pressure measured by the pressure sensor and controlling the compressor, the high-pressure on-off valve, and the low-pressure on-off valve.

The controller may close the high-pressure on-off valve and turn on the compressor in the pump-down mode.

The controller may close the low-pressure on-off valve and turn off the compressor when the pressure measured by the pressure sensor reaches a set pressure after the compressor is turned on in the pump-down mode.

The controller may operate the compressor at a maximum operating frequency in the pump-down mode.

The high-pressure on-off valve may be disposed between the expansion mechanism and the high-pressure service valve during the cooling cycle.

The cooling cycle may further include an accumulator for preventing the liquid refrigerant from being sucked into the compressor, and the low pressure on/off valve may be disposed between the low pressure service valve and the accumulator during the cooling cycle.

According to a preferred embodiment of the present invention, since the refrigerant pump-down can be automatically performed by the high-pressure on-off valve and the low-pressure on-off valve, there is an advantage that the user's convenience can be improved.

In addition, there is no need for a user to directly close the service valve, so there is an advantage that a malfunction due to a user's operation mistake can be prevented.

In addition, since the refrigerant pump-down is performed automatically, the refrigerant recovery amount may be constant. Accordingly, it is possible to calculate the amount of refrigerant to be additionally sealed, and there is an advantage in that it is possible to prevent system damage, degradation of performance, and cost increase due to insufficient refrigerant or overcharging.

1 is a schematic diagram of an air conditioner according to an embodiment of the present invention.
2 is a block diagram of an air conditioner according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a flow of refrigerant in a pump-down mode of the air conditioner shown in FIG. 2 .
4 is a control block diagram of an air conditioner according to an embodiment of the present invention.
5 is a flowchart illustrating an example of a control method in a pump-down mode of the air conditioner according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with drawings.

1 is a schematic diagram of an air conditioner according to an embodiment of the present invention.

Referring to FIG. 1 , an air conditioner according to an embodiment of the present invention may include an outdoor unit O and an indoor unit I.

<Outdoor unit and indoor unit>

The types of the outdoor unit O and the indoor unit I are not limited. As an example, the indoor unit (I) may be a wall-mounted type as shown in FIG. 1 . In addition, the indoor unit (I) may be a stand-up type installed on the floor or a stand type.

The outdoor unit O may be disposed outdoors, and the indoor unit I may be disposed indoors.

The indoor unit (I) may perform cooling or heating of the room, and the outdoor unit (O) may perform heat exchange with the outside air to satisfy the heating/cooling load according to the cooling or heating of the indoor unit (I).

The housing 2 of the outdoor unit O may be provided with an air inlet 4 and an air outlet (not shown). The air inlet 4 may be formed on the front surface of the housing 2 , and the air outlet may be formed on the rear surface of the housing 2 .

The refrigerant may alternately reciprocate between the outdoor unit (O) and the indoor unit (I). To this end, the outdoor unit O and the indoor unit I may be connected to the first connection flow path 26 and the second connection flow path 27 . The directions of the refrigerant flowing into the first connection passage 26 and the second connection passage 27 may be opposite to each other.

A compressor 10 , an outdoor heat exchanger 30 , and an expansion mechanism 40 , which will be described later, may be disposed in the outdoor unit O . An indoor heat exchanger 50 to be described later may be disposed in the indoor unit I.

<Service valve>

Service valves 60 and 70 may be provided in the outdoor unit O. In more detail, the outdoor unit O may include a high-pressure service valve 60 connected to the first connection passage 26 and a low-pressure service valve 70 connected to the second connection passage 27 .

Each of the service valves 60 and 70 may be arranged to be accessible from the outside of the housing 2 . In more detail, each of the service valves 60 and 70 may be provided on the outer surface of the housing 2 or located in the cutout 3 in which a portion of the housing 2 is cut. This allows the user to directly open or close each service valve 60 , 70 without removing the housing 2 .

Each of the service valves 60 and 70 may be provided with a cap. A user may open the cap and lock or open each service valve 60 , 70 using a tool such as a wrench.

2 is a block diagram of an air conditioner according to an embodiment of the present invention.

Hereinafter, the configuration of the air conditioner according to an embodiment of the present invention will be described in detail with reference to FIG. 2 .

The air conditioner according to an embodiment of the present invention may include a cooling cycle 1 in which a refrigerant circulates, a high-pressure on-off valve 13 , a low-pressure on-off valve 14 , and a pressure sensor 16 .

<Cooling cycle>

The cooling cycle 1 may include a compressor 10 , an outdoor heat exchanger 30 , an expansion mechanism 40 , and an indoor heat exchanger 50 . The cooling cycle 1 may further include a four-way valve 20 and an accumulator 15 .

The compressor 10 , the four-way valve 20 , the outdoor heat exchanger 30 , the accumulator 15 , and the expansion mechanism 40 may be disposed in the outdoor unit O . The indoor heat exchanger 50 may be disposed in the indoor unit I.

<Connection relationship between each component included in the cooling cycle>

Briefly describing the connection relationship of each configuration, the compressor 10 may be connected to the four-way valve 20 through the suction passage 12 and the discharge passage 11 . The four-way valve 20 may be connected to the outdoor heat exchanger 30 through the first flow path 21 . The outdoor heat exchanger 30 may be connected to the expansion mechanism 40 through the second flow path 22 . The expansion mechanism 40 may be connected to the internal heat exchanger 50 through the third flow path 23 . The indoor heat exchanger 50 may be connected to the four-way valve 20 through the fourth flow passage 24 .

The third flow path 23 may include a first connection flow path 26 and a first internal flow path 25 , and the fourth flow path 24 includes a second connection flow path 27 and a second internal flow path 28 . may include

The first internal flow path 25 may refer to a portion of the third flow path 23 disposed inside the outdoor unit O. The first internal flow path 25 may connect the expansion mechanism 40 and the high-pressure service valve 60 .

The first connection flow path 26 may mean a portion of the third flow path 23 disposed outside the outdoor unit O. The first connection passage 26 may connect the high-pressure service valve 60 and the indoor heat exchanger 50 . Accordingly, a portion of the first connection flow path 26 may be disposed inside the indoor unit I.

The second connection flow path 27 may refer to a portion of the fourth flow path 24 that is disposed outside the outdoor unit O. The second connection passage 27 may connect the low pressure service valve 70 and the indoor heat exchanger 50 . Accordingly, a portion of the second connection flow path 27 may be disposed inside the indoor unit I.

The second internal flow path 28 may refer to a portion of the fourth flow path 24 that is disposed inside the outdoor unit O. The second internal flow path 28 may connect the four-way valve 20 and the low pressure service valve 70 .

<compressor>

The compressor 10 may compress the refrigerant. The compressor 10 is preferably an inverter compressor whose driving frequency is regulated.

A discharge passage 11 and a suction passage 12 may be respectively connected to the compressor 10 . The compressor 10 may suck and compress the refrigerant flowing into the suction passage 12 , and may discharge the compressed refrigerant to the discharge passage 11 .

<4 way valve>

The four-way valve 20 may be connected to each of the discharge flow path 11 and the suction flow path 12 .

In addition, the four-way valve 20 may be connected to each of the first flow path 21 and the fourth flow path 24 . In more detail, the four-way valve 20 may be connected to each of the first flow path 21 and the second internal flow path 28 .

In the cooling mode, the four-way valve 20 may communicate the discharge passage 11 and the outdoor heat exchanger 30 , and the suction passage 12 and the indoor heat exchanger 50 may communicate with each other. In more detail, in the cooling mode, the four-way valve 20 may communicate the discharge flow path 11 and the first flow path 21 , and the suction flow path 12 and the fourth flow path 24 may communicate with each other.

In the heating mode, the four-way valve 20 may communicate the discharge flow path 11 with the indoor heat exchanger 50 and the suction flow path 12 and the outdoor heat exchanger 30 may communicate with each other. In more detail, in the heating mode, the four-way valve 20 may communicate the discharge flow path 11 and the fourth flow path 24 , and may communicate the suction flow path 12 and the first flow path 21 .

<Outdoor Heat Exchanger>

The outdoor heat exchanger 30 may exchange heat with the refrigerant and the outdoor air. In more detail, the outdoor heat exchanger 30 may exchange heat between the air blown by the outdoor fan 31 and the refrigerant passing through the outdoor heat exchanger 30 . Accordingly, the higher the rotation speed of the outdoor fan 31, the more active the heat exchange between the air and the refrigerant.

The outdoor fan 31 may be disposed to face the outdoor heat exchanger 30 .

In the cooling mode, the outdoor heat exchanger 30 may act as a condenser. That is, the outdoor heat exchanger 30 may condense the refrigerant by heat-exchanging it with the outdoor air. As the rotation speed of the outdoor fan 31 increases, the condensation of the refrigerant may become more active.

In the heating mode, the outdoor heat exchanger 30 may act as an evaporator, that is, the outdoor heat exchanger 30 may heat-exchange refrigerant with outside air to evaporate it. The faster the rotation speed of the outdoor fan 31, the more active the evaporation of the refrigerant.

One side of the outdoor heat exchanger 30 may be connected to the four-way valve 20 through a first flow path 21 , and the other side may be connected to the expansion mechanism 40 through a second flow path 22 .

<Inflation mechanism>

The expansion mechanism 40 may expand the refrigerant passing through the expansion mechanism 40 .

The expansion mechanism 40 is preferably an electric expansion valve (EEV), but is not limited thereto. An electronic expansion valve (EEV) is a type of expansion valve whose opening degree can be controlled.

The expansion mechanism 40 may be disposed in the outdoor unit O. That is, the expansion device 40 may be an outdoor expansion device.

The expansion mechanism 40 may be connected to the outdoor heat exchanger 30 through the second flow path 22 , and may be connected to the indoor heat exchanger 50 through the third flow path 23 .

In the cooling mode, the refrigerant condensed in the outdoor heat exchanger 30 may flow to the expansion mechanism 40 along the second flow path 22 . The refrigerant may be expanded while passing through the expansion mechanism 40 , and may flow to the indoor heat exchanger 50 along the third flow path 23 .

In the heating mode, the refrigerant condensed in the indoor heat exchanger 50 may flow to the expansion mechanism 40 along the third flow path 23 . The refrigerant may be expanded while passing through the expansion mechanism 40 , and may flow to the outdoor heat exchanger 30 along the second flow path 22 .

<High pressure service valve>

Meanwhile, a high-pressure service valve 60 may be installed in the third flow path 23 . In more detail, the first internal flow path 25 may connect the high-pressure service valve 60 and the expansion mechanism 40 , and the first connection flow path 26 includes the high-pressure service valve 60 and the indoor heat exchanger 50 . can be connected

The high-pressure service valve 60 may control the refrigerant flow in the third flow path 23 . The high-pressure service valve 60 may be a liquid pipe-side service valve.

Normally, the high-pressure service valve 60 is opened and the refrigerant may flow through the third flow path, but when the user closes the high-pressure service valve 60, the refrigerant flowing into the first internal flow path 25 is 26) cannot flow.

<High pressure on/off valve>

The high-pressure on-off valve 13 may be disposed between the outdoor heat exchanger 30 and the high-pressure service valve 60 during the cooling cycle 1 . That is, the high-pressure on/off valve 13 may be disposed in the second flow path 22 or the first internal flow path 25 .

Preferably, the high-pressure on-off valve 13 may be disposed between the expansion mechanism 40 and the high-pressure service valve 60 during the cooling cycle 1 . That is, the high-pressure on-off valve 13 may be disposed in the first internal flow path 25 .

Compared to when the high-pressure on-off valve 13 is installed in the second flow path 22 , the high-pressure on-off valve 13 is installed in the first internal flow path 25 , thereby increasing the amount of refrigerant recovered in the pump-down mode. There is this.

<Indoor heat exchanger>

Meanwhile, the indoor heat exchanger 50 may heat-exchange refrigerant and air. In more detail, the indoor heat exchanger 50 may exchange heat between the air blown by the indoor fan 51 and the refrigerant passing through the indoor heat exchanger 50 . Accordingly, the faster the rotation speed of the indoor fan 51, the more active the heat exchange between the air and the refrigerant.

In the cooling mode, the indoor heat exchanger 50 may act as an evaporator. That is, the indoor heat exchanger 50 may evaporate the refrigerant by heat-exchanging it with the outside air. The faster the rotation speed of the indoor fan 51 is, the more active the evaporation of the refrigerant is.

In the heating mode, the indoor heat exchanger 50 may act as a condenser. That is, the indoor heat exchanger 50 may condense the refrigerant by heat-exchanging it with the outdoor air. As the rotation speed of the indoor fan 51 increases, the condensation of the refrigerant may become more active.

One side of the indoor heat exchanger 50 may be connected to the expansion mechanism 40 through the third flow path 23 , and the other side may be connected to the fourth flow path 22 , the four-way valve 20 .

<Low pressure service valve>

A low pressure service valve 70 may be installed in the fourth flow path 24 . In more detail, the second internal flow path 28 may connect the low pressure service valve 70 and the four-way valve 20 , and the second connection flow path 27 includes the low pressure service valve 70 and the indoor heat exchanger 50 . can be connected

The low pressure service valve 70 may control the refrigerant flow in the fourth flow passage 24 . The low pressure service valve 70 may be an engine-side service valve.

Normally, the low pressure service valve 70 is opened and the refrigerant flows through the fourth flow path 24 , but when the user closes the low pressure service valve 70 , the refrigerant flowing into the second connection flow path 27 is transferred to the second It cannot flow into the internal flow path 28 .

<Low pressure on/off valve>

The low pressure on/off valve 14 may be disposed between the low pressure service valve 70 and the compressor 10 during the cooling cycle 1 . That is, the low-pressure on-off valve 14 may be disposed in the second internal flow path 28 or the suction flow path 12 .

Preferably, the low-pressure on-off valve 14 may be disposed between the low-pressure service valve 70 and the accumulator 15 during the cooling cycle 1 .

In the pump-down mode, the refrigerant may be recovered into the outdoor unit O by being accommodated between the high-pressure on-off valve 13 and the low-pressure on-off valve 14 during the cooling cycle. This will be described in detail later.

<Accumulator>

The accumulator 15 may be disposed in the suction passage 12 .

The accumulator 15 may prevent the liquid refrigerant from being sucked into the compressor 10 . In more detail, the accumulator 15 may receive the liquid refrigerant among the introduced refrigerants and discharge only the refrigerant in a gaseous state. As a result, the compressor 10 can suck only the gaseous refrigerant.

<Pressure sensor>

The pressure sensor 16 may be connected to the cooling cycle 1 . A position to which the pressure sensor 16 is connected in the cooling cycle 1 may be changed as needed. The pressure sensor 16 may be connected to a portion of the cooling cycle 1 except between the outdoor heat exchanger 30 and the high-pressure on-off valve 13 .

For example, the pressure sensor 16 may be installed in the suction flow path 16 or installed outside the outdoor unit O.

The pressure sensor 16 may measure the pressure of the refrigerant flowing along the cooling cycle 1 , and transmit the measured pressure value to the controller 90 to be described later.

As pump-down progresses, the pressure of the refrigerant measured by the pressure sensor 16 may be lowered, and when the pressure measured by the pressure sensor 16 reaches a set pressure, the pump-down mode may be terminated. This will be described in detail later.

FIG. 3 is a diagram illustrating a flow of refrigerant in a pump-down mode of the air conditioner shown in FIG. 2 .

<pump-down mode>

Hereinafter, an operation of the air conditioner in the pump-down mode according to the embodiment of the present invention will be described with reference to FIG. 3 .

Before entering the pump-down mode, the refrigerant may be spread and located inside the components constituting the cooling cycle and inside the flow paths connecting each component. The pump-down mode is a mode for collecting and recovering the refrigerant inside the outdoor unit (O).

The pump-down mode is basically similar to the cooling mode, but the high-pressure on-off valve 13 and the low-pressure on-off valve 14 are sequentially closed. It will be described in detail below.

In the pump-down mode, in a state in which the high-pressure on-off valve 13 is closed, the compressor 10 may compress the suctioned refrigerant. At this time, the low pressure on-off valve 14 may be in an open state.

In addition, in the pump-down mode, the four-way valve 20 may communicate the suction passage 12 and the indoor heat exchanger 50 . Accordingly, the refrigerant evaporated in the indoor heat exchanger 50 may be sucked into the compressor 10 through the fourth passage 24 and the suction passage 12 .

Due to the suction force of the compressor 10 , the refrigerant between the high-pressure on-off valve 13 and the compressor 10 may flow in the compressor 10 direction along the refrigerant flow direction. That is, the refrigerant in the suction passage 12 , the fourth passage 24 , the indoor heat exchanger 50 , and the third passage 23 may be sucked into the compressor 10 .

Since the high-pressure on-off valve 13 is closed in the pump-down mode, the suction force of the compressor 10 may not be applied to the refrigerant located on the opposite side of the high-pressure on-off valve 13 with respect to the high-pressure service valve 60 .

In the pump-down mode, the indoor heat exchanger 50 may act as an evaporator. Accordingly, the refrigerant flowing into the indoor heat exchanger 50 may be evaporated while passing through the indoor heat exchanger 50 .

In the pump-down mode, the indoor fan 51 may rotate at the maximum speed. Accordingly, evaporation of the refrigerant in the indoor heat exchanger 50 may occur actively.

The refrigerant evaporated in the indoor heat exchanger 50 may flow to the suction passage 12 through the fourth passage 24 . The refrigerant flowing into the suction passage 12 may be introduced into the accumulator 15 . The accumulator 15 may store the liquid refrigerant and take out the gaseous refrigerant, and the gaseous refrigerant may be sucked into the compressor 10 and compressed.

Since a certain amount of refrigerant is stored in the accumulator 15, there is an advantage in that the recovery amount of the refrigerant is increased during pump-down.

Meanwhile, the compressor 10 may compress the sucked refrigerant and discharge it to the discharge passage 11 .

In the pump-down mode, the four-way valve 20 may communicate the discharge passage 11 and the outdoor heat exchanger 30 . Accordingly, the refrigerant discharged to the discharge passage 11 may flow to the outdoor heat exchanger 30 along the first flow passage 21 .

In the pump-down mode, the outdoor heat exchanger 30 may act as a condenser. Accordingly, the refrigerant may be condensed while passing through the outdoor heat exchanger 30 .

In the pump-down mode, the outdoor fan 31 may rotate at the maximum speed. Accordingly, condensation of the refrigerant may occur actively in the outdoor heat exchanger 30 .

When the high-pressure on-off valve 13 is installed in the first internal flow path 25 , the refrigerant condensed in the outdoor heat exchanger 30 may flow through the expansion mechanism 40 to the high-pressure on-off valve 13 . At this time, since the high-pressure on-off valve 13 is in a closed state, the refrigerant may not pass through the high-pressure on-off valve 13 . When the high-pressure on-off valve 13 is installed in the second flow passage 22 , the refrigerant condensed in the outdoor heat exchanger 30 may be blocked by the high-pressure on-off valve 13 and may not reach the expansion mechanism 40 .

Since the refrigerant does not pass through the high-pressure on-off valve 13 , the refrigerant may not circulate along the cooling cycle 1 , and may collect in the previous part of the high-pressure on-off valve 13 along the flow direction of the refrigerant.

Since most of the refrigerant is collected in the first flow path 21 , the outdoor heat exchanger 30 , and the second flow path 22 , the refrigerant in other parts can be reduced, and thus the pressure value measured by the pressure sensor 16 . can be lowered. When the pressure measured by the pressure sensor 16 is sufficiently low to reach the set pressure, the low-pressure on-off valve 14 is closed, and the compressor 10 can be turned off.

When the compressor 10 is turned off, since the suction force of the compressor 10 does not act, the refrigerant located in the suction passage 12 may flow backward. At this time, since the low-pressure on-off valve 14 is in the closed state, the reverse flow of the refrigerant can be prevented.

Consequently, according to the pump-down mode, the refrigerant spread throughout the cooling cycle may be collected and recovered by the outdoor unit O. In more detail, when the pump-down mode is completed, the recovered refrigerant may be trapped between the high-pressure on-off valve 13 and the low-pressure on-off valve 14 .

Accordingly, the pump-down can be performed automatically even if the user does not separately operate the service valves 60 and 70, and there is an advantage that the amount of refrigerant above a certain level can always be recovered.

Afterwards, the user may close each service valve 60, 70 in turn. At this time, the order of locking the high-pressure service valve 60 and the low-pressure service valve 70 is irrelevant. Accordingly, it is possible to prevent user confusion. In addition, even if the user does not distinguish between the high-pressure service valve 60 and the low-pressure service valve 70 , there is an advantage that a malfunction does not occur and the pump-down can be stably performed.

Thereafter, the user can purge and separate the residual refrigerant by slightly loosening the piping connection flare. Accordingly, the refrigerant can be stably recovered and the air conditioner can be moved.

4 is a control block diagram of an air conditioner according to an embodiment of the present invention.

Referring to FIG. 4 , the air conditioner according to an embodiment of the present invention may include a controller 90 .

<controller>

The controller 90 may be provided in the indoor unit (I) and/or the outdoor unit (O).

The controller 90 may include an input unit provided with a user interface. A user may directly input a command into the user interface or may input a command to an input unit through a remote control or the like.

An operation mode of the air conditioner may be determined by a user's command. For example, the user may select any one of a heating mode, a cooling mode, and a pump-down mode. In addition, the user may input a desired temperature, an air volume, a wind direction, and the like.

In addition, the controller 90 may include a communication unit. The communication unit may perform wired/wireless communication with a separate terminal or a central controller.

The controller 90 may receive the pressure measured by the pressure sensor 14 .

The controller 90 may control the compressor 10 , the high-pressure on-off valve 13 , and the low-pressure on-off valve 14 . In addition, the controller 90 may control the outdoor fan 31 and the indoor fan 51 , and if necessary, the controller 90 may be configured to further control an additional configuration.

The controller 90 may turn on/off the compressor 10 and may control an operating frequency of the compressor 10 .

The controller 90 may turn on/off the outdoor fan 31 and the indoor fan 51, respectively. Also, the controller 90 may control the respective rotational speeds of the outdoor fan 31 and the indoor fan 51 .

The controller 90 may turn on/off the high-pressure on-off valve 13 and the low-pressure on-off valve 14 .

5 is a flowchart illustrating an example of a control method in a pump-down mode of the air conditioner according to an embodiment of the present invention.

<Detailed control in pump-down mode>

The controller 90 may start a pump-down mode of the air conditioner according to a user's input or the like.

In the pump-down mode, the controller 90 controls the four-way valve 20 to communicate the discharge flow path 11 of the compressor 10 with the outdoor heat exchanger 30 (S1). After controlling the four-way valve 20, the controller 90 may turn on the compressor 10 and close the high-pressure on/off valve 13 (S2). In addition, the controller 90 may keep the low pressure on-off valve 14 open.

In this case, the controller 90 may operate the compressor 10 at the maximum operating frequency. Accordingly, there is an advantage in that the flow rate of the refrigerant is increased so that the pump down can be performed quickly.

Since the refrigerant discharged from the compressor 10 flows to the high-pressure on-off valve 13 and does not pass through the high-pressure on-off valve 13, it can be collected before the high-pressure on-off valve 13 with respect to the flow direction of the refrigerant. In addition, the refrigerant positioned after the high-pressure on-off valve 13 with respect to the flow direction of the refrigerant may be sucked into the compressor through the suction passage 12 of the compressor 10 . Accordingly, the refrigerant in the indoor unit (I) may be recovered into the outdoor unit (O).

The controller 90 may determine whether the pressure measured by the pressure sensor 16 has reached a preset set pressure (S3).

For example, when the pressure sensor 16 is connected to the suction flow path 12 , the refrigerant sucked into the compressor 1 through the suction flow path 12 may gradually decrease as the pump down proceeds, and the pressure sensor 16 ), the measured pressure may gradually decrease. The set pressure may be 0, which may mean that the refrigerant is all recovered so that the pressure in the suction passage 12 is equal to atmospheric pressure.

When the pressure value measured by the pressure sensor 16 reaches the set pressure, it means that the refrigerant has been sufficiently recovered, so the controller 90 closes the low-pressure on-off valve 14 and turns off the compressor 10 (S4) . Accordingly, the pump-down mode of the air conditioner may be ended.

As described above, even when the compressor 10 is turned off, the recovered refrigerant may not leak because it is trapped between the high-pressure on-off valve 13 and the low-pressure on-off valve 14 . Thereby, the pump down can be completed.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains.

Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments.

The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

10: Compressor 13: High-pressure on-off valve
14: low pressure on-off valve 15: accumulator
16: pressure sensor 20: four-way valve
30: outdoor heat exchanger 40: expansion mechanism
50: indoor heat exchanger 60: high pressure service valve
70: low pressure service valve 90: controller
I: Indoor unit O: Outdoor unit

Claims (6)

a cooling cycle comprising a compressor, an outdoor heat exchanger, an expansion mechanism, a four-way valve and an indoor heat exchanger;
an outdoor unit including the compressor, the outdoor heat exchanger and the expansion mechanism, and an outdoor fan for guiding air to the outdoor heat exchanger, the outdoor unit having a high pressure service valve and a low pressure service valve;
an indoor unit in which the indoor heat exchanger and an indoor fan for guiding air to the indoor heat exchanger are disposed;
a high-pressure on/off valve disposed between the outdoor heat exchanger and the high-pressure service valve during the cooling cycle;
a low pressure on/off valve disposed between the low pressure service valve and the compressor during the cooling cycle;
a pressure sensor installed in the cooling cycle and measuring the pressure of the refrigerant; and
and a controller receiving the pressure measured by the pressure sensor and controlling the compressor, the high-pressure on-off valve, the low-pressure on-off valve, the indoor fan, and the outdoor fan,
The compressor sucks the refrigerant flowing into the suction passage and compresses it, and discharges the compressed refrigerant to the discharge passage,
The four-way valve is connected to the suction passage and the discharge passage, respectively,
The controller is
In pump-down mode, close the high-pressure on-off valve and turn on the compressor,
After the compressor is turned on, when the pressure measured by the pressure sensor reaches the set pressure, the low-pressure on-off valve is closed and the compressor is turned off,
Rotating the indoor fan and the outdoor fan at maximum speed,
When the compressor is turned on,
maintaining the low-pressure on-off valve in an open state,
The four-way valve communicates the suction passage with the indoor heat exchanger so that the refrigerant evaporated in the indoor heat exchanger is sucked into the compressor. delete delete The method of claim 1,
The controller is
An air conditioning system that operates the compressor at the maximum operating frequency in pump-down mode. The method of claim 1,
and the high-pressure on-off valve is disposed between the expansion mechanism and the high-pressure service valve during the cooling cycle. The method of claim 1,
The cooling cycle is
Further comprising an accumulator for preventing the liquid refrigerant from being sucked into the compressor,
The low pressure on/off valve is disposed between the low pressure service valve and the accumulator during the cooling cycle.

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