KR20100088377A - Air conditioner and defrosting driving method of the same - Google Patents

Abstract

PURPOSE: An air conditioner and a defrosting method thereof are provided to reduce the pressure of a pipe connecting a compressor to an outdoor heat exchanger performing defrosting operation by opening the defrosting valve of an outdoor heat exchanger not performing the defrosting operation. CONSTITUTION: A first defrosting valve of the first outdoor heat exchanger is opened to initiate the defrosting operation of the first outdoor heat exchanger(S3,S4). After the first defrosting valve is opened, a second defrosting valve of a second outdoor heat exchanger is opened(S6). After the second defrosting valve is opened, the first defrosting valve is closed to initiate the defrosting operation of the second outdoor heat exchanger(S8). After the first defrosting operation is initiated, it is determined whether the defrosting operation of the first outdoor heat exchanger has been completed. If yes, the first defrosting valve is opened and then the second defrosting valve is opened.

Description

Air conditioner and Defrosting driving method of the same}

The present invention relates to a defrosting operation method of an air conditioner, and more particularly, to open a defrost valve that is closed before closing an open defrost valve among a plurality of defrost valves and to facilitate opening of a defrost valve. It relates to a driving method.

In general, an air conditioner is a device for cooling or heating a room using a refrigeration cycle including a compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger. That is, it may be configured as a cooler for cooling the room, a heater for heating the room. And it may be configured as a combined air conditioning and air conditioner for cooling or heating the room.

When the air conditioner is configured as a combined air conditioning and air conditioner, the air conditioner is configured to include a four-way valve for changing the flow path of the refrigerant compressed by the compressor according to the cooling operation and the heating operation. That is, during the cooling operation, the refrigerant compressed by the compressor flows through the four-way valve to the outdoor heat exchanger, and the outdoor heat exchanger acts as a condenser. The refrigerant condensed in the outdoor heat exchanger is expanded in the expansion mechanism and then flows into the indoor heat exchanger. At this time, the indoor heat exchanger acts as an evaporator, and the refrigerant evaporated from the indoor heat exchanger passes through the four-way valve and flows into the compressor.

Meanwhile, during the heating operation, the refrigerant compressed by the compressor flows through the four-way valve to the indoor heat exchanger, and the indoor heat exchanger acts as a condenser. The refrigerant condensed in the indoor heat exchanger is expanded in the expansion mechanism and then flows into the outdoor heat exchanger. At this time, the outdoor heat exchanger acts as an evaporator, and the refrigerant evaporated from the outdoor heat exchanger again flows through the four-way valve to the compressor.

The air conditioner as described above generates water on the surface of the heat exchanger that acts as an evaporator during operation, and water is generated on the surface of the indoor heat exchanger in the case of the cooling operation and on the surface of the outdoor heat exchanger in the case of the heating operation. In this case, when the condensate generated on the surface of the outdoor heat exchanger freezes during the heating operation, the heating performance is reduced by preventing the smooth flow and heat exchange of the outdoor air.

Therefore, recent air conditioners have been produced to perform defrosting operations to remove condensed water that has formed. Defrosting operation can be performed in a variety of ways. In addition, some outdoor heat exchangers sequentially perform defrosting operation using a plurality of outdoor heat exchangers, and the other outdoor heat exchanger may supply heating to the room even during defrosting operation. Specifically, a part of the high pressure refrigerant compressed by the compressor flows to an outdoor heat exchanger performing defrosting operation, and the remainder of the refrigerant compressed in the compressor flows to an outdoor heat exchanger which does not perform defrosting operation through an indoor heat exchanger and an expansion valve. Perform heating operation.

In order to perform the defrosting operation method, the air conditioner includes a plurality of pipes for flowing the refrigerant of the compressor through a plurality of outdoor heat exchangers and a defrost valve for opening and closing the pipes. The defrosting operation is performed by sequentially opening and closing the defrost valve connected to the outdoor heat exchanger performing the defrosting operation. That is, only the defrost valve connected to the pipe of the outdoor heat exchanger performing the defrosting operation is opened, and the defrost valve connected to the pipe of the outdoor heat exchanger not performing the defrosting operation is closed.

In the above defrosting operation method, in order to sequentially defrost all the outdoor heat exchangers, a process of closing the defrost valve of the outdoor heat exchanger in which the defrosting operation is completed and opening the defrost valve of the outdoor heat exchanger performing defrosting operation is performed. However, in this case, since the pressure of the refrigerant compressed in the compressor is concentrated in the pipe of the outdoor heat exchanger which performs the defrosting operation, there is a problem in that the defrost valve of the defrosted outdoor heat exchanger does not close.

The present invention is to solve the above-described problems, when the plurality of outdoor heat exchangers are defrosted sequentially, the outdoor heat exchanger to complete the defrosting operation by opening the defrost valve of the outdoor heat exchanger does not perform the defrosting operation for a certain time The present invention provides an air conditioner and a defrosting operation method of an air conditioner that can easily close a defrost valve.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the defrosting operation method of the air conditioner according to an embodiment of the present invention is a first defrosting operation of opening the first defrost valve of the first outdoor heat exchanger to start the defrosting operation of the first outdoor heat exchanger. The defrost valve opening step of opening the second defrost valve of the second outdoor heat exchanger after opening the first defrost valve and the defrost of the second outdoor heat exchanger by closing the first defrost valve after opening the second defrost valve. And a second defrosting operation step of starting the operation.

In addition, the defrosting operation method of the air conditioner according to an embodiment of the present invention, the second defrosting operation step of starting the defrosting operation of the second outdoor heat exchanger by opening the second defrost valve of the second outdoor heat exchanger, the second defrost After opening the valve, the defrost valve opening step of opening the first defrost valve of the first outdoor heat exchanger and after opening the first defrost valve, close the first defrost valve and the second defrost valve to close the first outdoor heat exchanger and the second. And a defrosting operation terminating step of terminating the defrosting operation of the outdoor heat exchanger.

And the air conditioner according to an embodiment of the present invention is a compressor for compressing the refrigerant, a hot gas pipe to which a portion of the refrigerant compressed by the compressor flows the four-way valve for the rest of the refrigerant compressed in the compressor, the four-way valve An indoor heat exchanger that exchanges heat with indoor air while the refrigerant passing through the air flows, an outdoor expansion mechanism in which the refrigerant heat exchanged in the indoor heat exchanger is expanded, and a first heat exchange in which defrosting operation is performed while the refrigerant passing through the hot gas pipe flows. Here, a second heat exchanger in which the heating operation is performed while the refrigerant expanded in the outdoor expansion mechanism flows. The hot gas pipe may include a first pipe connected to the first outdoor heat exchanger, a second pipe connected to the second outdoor heat exchanger, and a first defrost installed on the first pipe to open the defrosting operation of the first outdoor heat exchanger. And a second defrost valve installed in the valve and the second pipe and opened before the first defrost valve is closed.

In addition, the air conditioner according to an embodiment of the present invention is a compressor for compressing a refrigerant, a plurality of outdoor heat exchanger to perform a defrost operation sequentially while the refrigerant compressed in the compressor flows, a plurality of outdoor heat exchanger of the refrigerant compressed in the compressor And a plurality of pipes connected to the plurality of outdoor heat exchangers so as to flow into the air, and a plurality of defrost valves respectively installed on the plurality of pipes and partially opened to perform defrosting of the outdoor heat exchanger. In order to reduce the pressure of the plurality of pipes, at least one or more unopened defrost valves are opened before closing the open defrost valves.

Specific details of other embodiments are included in the detailed description and the drawings.

The air conditioner and the defrosting operation method of the air conditioner of the present invention having the above configuration has the following effects.

By opening the defrost valve of the outdoor heat exchanger that does not perform the defrosting operation, the pressure of the pipe connecting the outdoor heat exchanger and the compressor which performs the defrosting operation is reduced. Therefore, when the defrosting of the outdoor heat exchanger performing the defrosting operation can be easily closed, the defrost valve can be prevented from being damaged due to excessive flow pressure in the process of closing the defrosting valve.

Furthermore, the control of the defrost valve in accordance with the completion of defrosting can be precisely increased to increase the defrosting efficiency and heating efficiency.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

First embodiment

1 is a block diagram showing a refrigerant flow of the outdoor unit during the heating of the air conditioner according to the first embodiment of the present invention, Figure 2 is a configuration showing a refrigerant flow of the outdoor unit during the defrost operation of the first outdoor heat exchanger of the first embodiment 3 is a block diagram showing the flow of refrigerant when the second defrost valve is opened before closing the first defrost valve of the first embodiment, and FIG. 4 is a defrosting operation of the second outdoor heat exchanger of the first embodiment. It is a block diagram which shows the flow of the refrigerant | coolant of an outdoor unit. 1 through 4, the overall configuration of the air conditioner of the present embodiment will be described.

Although not shown, the air conditioner of the present embodiment may include a plurality of indoor units and a plurality of outdoor units. A plurality of indoor units and a plurality of outdoor units are connected by a refrigerant pipe, and the plurality of indoor units are installed at a plurality of places where a user wants air conditioning.

1, the outdoor unit of the air conditioner of this embodiment includes a compressor, a hot gas pipe, a four-way valve, an indoor heat exchanger, an outdoor expansion mechanism, and a plurality of outdoor heat exchangers.

Compressors 11 and 13 compress the refrigerant. One of the compressors 11 and 13 may be a variable capacity compressor such as an inverter compressor, and the other may be a constant speed compressor. In addition, a gas-liquid separator 14 is connected to the suction side of the compressors 11 and 13, and an oil separator 16 and a check valve are installed on the discharge side.

In the hot gas pipe 20, a part of the refrigerant compressed by the compressors 11 and 13 flows. Specifically, a part of the high temperature and high pressure refrigerant compressed by the compressors 11 and 13 during the defrosting operation passes through the hot gas pipe 20 and enters the outdoor heat exchangers 80 and 90 so as to open the outdoor heat exchangers 80 and 90. Defrost

The hot gas pipe 20 includes a main pipe 21, a first pipe 23, a second pipe 25, a first defrost valve 27, and a second defrost valve 29.

The main pipe 21 flows a part of the refrigerant compressed by the compressors 11 and 13. Therefore, it may be connected to the pipe between the indoor heat exchanger (not shown) of the four-way valve 30. However, in this embodiment, one side of the main pipe 21 is connected between the compressor (11, 13) and the four-way valve 30. Therefore, compared to the case where the refrigerant compressed by the compressors 11 and 13 passes through the four-way valve 30 and flows to the main pipe 21, the pressure loss of the refrigerant can be reduced. And the other side of the main pipe 21 is connected to the first pipe 23 and the second pipe 25 to be described later. Therefore, the refrigerant passing through the main pipe 21 flows into the first pipe 23 and the second pipe 25.

The first pipe 23 communicates with the first outdoor heat exchanger 80. The first pipe 23 is provided with a first defrost valve 27 for opening and closing the first pipe 23. The first defrost valve 27 is opened during the defrosting operation of the first outdoor heat exchanger 80. Therefore, the high temperature and high pressure refrigerant compressed by the compressors 11 and 13 is introduced into the first outdoor heat exchanger 80 through the main pipe 21 and the first pipe 23. The first outdoor heat exchanger 80 is defrosted while the high temperature and high pressure refrigerant flows.

The second pipe 25 is in communication with the second outdoor heat exchanger (70). The second pipe 25 is provided with a second defrost valve 29 for opening and closing the second pipe 25. The second defrost valve 29 is opened during the defrosting operation of the second outdoor heat exchanger 70. Therefore, the high temperature and high pressure refrigerant compressed by the compressors 11 and 13 is introduced into the second outdoor heat exchanger 70 through the main pipe 21 and the second pipe 25. The second outdoor heat exchanger 70 is defrosted while the high temperature and high pressure refrigerant flows.

In the present embodiment, the second outdoor heat exchanger 70 performs a heating operation during the defrosting operation of the first outdoor heat exchanger 80. In this case, therefore, the first defrost valve 27 is open and the second defrost valve 29 is closed. When it is determined that the defrosting operation of the first outdoor heat exchanger 80 is completed, the first defrost valve 27 is closed and the second defrost valve 29 is opened to heat the first outdoor heat exchanger 80. The two outdoor heat exchangers 70 perform the defrosting operation.

Here, the refrigerant compressed by the compressors 11 and 13 during the defrosting operation of the first outdoor heat exchanger 80 flows only the first pipe 23. Therefore, the flow pressure of the flow refrigerant is all applied to the first pipe 23. The first defrost valve 27 does not close well due to the flow pressure. Therefore, in the present embodiment, the first defrost valve 27 and the second defrost valve 29 are temporarily opened simultaneously before closing the first defrost valve 27. Therefore, the flow pressure of the refrigerant compressed by the compressors 11 and 13 is distributed to the first pipe 23 and the second pipe 25. Therefore, the first defrost valve 27 can be closed more easily than when only the first defrost valve 27 is open.

The four-way valve 30 converts the flow direction of the refrigerant according to the air conditioning operation of the air conditioner. That is, during the cooling operation, the refrigerant evaporated in the indoor heat exchanger (not shown) flows to the compressors 11 and 13, and the refrigerant compressed in the compressor flows to the outdoor heat exchanger 70 and 80. In the heating operation, the refrigerant evaporated in the outdoor heat exchangers 70 and 80 flows to the compressors 11 and 13, and the refrigerant compressed in the compressor flows to the indoor heat exchanger (not shown). In the defrosting operation, the refrigerant evaporated in the outdoor heat exchanger (70, 80) flows to the compressors (11, 13), and the refrigerant not flowed to the main pipe (21) of the refrigerant compressed in the compressor (11, 13) indoors. Flow through a heat exchanger (not shown).

An indoor heat exchanger (not shown) cools or heats indoor air by heat exchange between a refrigerant and indoor air. Specifically, the refrigerant is evaporated during the cooling operation to cool the indoor air, and the refrigerant compressed by the compressors 11 and 13 is condensed during the heating operation to heat the indoor air. And during the defrosting operation while the refrigerant passing through the four-way valve 30 flows to the indoor air. Although not shown, in the present embodiment, a plurality of indoor heat exchangers may be provided to cool and heat a plurality of indoor spaces.

The outdoor expansion mechanisms 40 and 50 include expansion valves 41 and 51 and check valves 43 and 53. The refrigerant condensed in the indoor heat exchanger during the heating operation is expanded while passing through the expansion valves 41 and 51. In the cooling operation, the refrigerant passing through the outdoor heat exchangers 70 and 80 passes through the check valves 43 and 53 and is expanded by an indoor expansion mechanism (not shown).

The number of outdoor expansion mechanisms 40 and 50 corresponds to the number of outdoor heat exchangers 70 and 80. In the present embodiment, the outdoor expansion mechanisms 40 and 50 are the first outdoor expansion mechanism 40 connected to the first outdoor heat exchanger 80 and the second outdoor expansion mechanism 50 connected to the second outdoor heat exchanger 70. It includes. Specifically, the expansion valves 41 and 51 in the present embodiment are configured as electromagnetic expansion valves, and the defrosting operation of each outdoor heat exchanger 70 and 80 limits the opening degree of the electromagnetic expansion valve to the minimum degree of outdoor operation during defrosting operation. The refrigerant is prevented from entering the heat exchangers 70 and 80.

The plurality of outdoor heat exchangers 70 and 80 condense / evaporate the flowing refrigerant using the flowing outdoor air. In the defrosting operation, moisture compressed in the outdoor heat exchangers 70 and 80 is removed while the refrigerant compressed by the compressor flows in the compressors 11 and 13.

The outdoor heat exchangers 70 and 80 may be provided in various numbers. However, the outdoor heat exchangers 70 and 80 include a first outdoor heat exchanger 80 and a second outdoor heat exchanger 70. During the cooling operation, the refrigerant flowing in the first outdoor heat exchanger 80 and the second outdoor heat exchanger 70 is condensed by outdoor air. The refrigerant flowing in the first outdoor heat exchanger 80 and the second outdoor heat exchanger 70 is evaporated by the outdoor air during the heating operation.

In the defrosting operation, the first outdoor heat exchanger 80 performs the defrosting operation while the refrigerant passing through the compressors 11 and 13, the main pipe 21, and the first pipe 27 flows. At this time, the heating operation is performed while the refrigerant passing through the second outdoor expansion valve 51 flows to the second outdoor heat exchanger 70. As a result, in the present invention, some of the plurality of outdoor heat exchangers 70 and 80 perform defrosting operation, and others perform heating operation. The defrosting operation can be performed while still supplying heated air to the room.

On the other hand, the first outdoor heat exchanger 80 and the first temperature sensor (80a) is installed in the second outdoor heat exchanger (70), the second temperature sensor (80a) is respectively discharged from each outdoor heat exchanger (70, 80) Measure the temperature of the refrigerant. In addition, an additional third temperature sensor 100 may be provided in the outdoor heat exchangers 70 and 80 to measure the temperature of the refrigerant flowing into each outdoor heat exchanger 70 and 80 or the temperature of the outdoor air. And to determine whether the defrost can measure the temperature of the outdoor air passed through the outdoor heat exchanger (70, 80).

Referring to the operation and defrosting operation method of the first embodiment of the air conditioner of the present invention configured as described above are as follows.

5 is a block diagram showing the flow of the refrigerant during the cooling operation of the air conditioner according to the present invention. Referring to Figure 5 will be described the flow of the refrigerant during the cooling operation of the air conditioner of the present embodiment.

In the cooling operation, the refrigerant is compressed by the compressors 11 and 13 and flows to the four-way valve 30. At this time, the first defrost valve 27 and the second defrost valve 29 are closed so that all of the refrigerant compressed by the compressors 11 and 13 flows to the four-way valve 30. The refrigerant passing through the four-way valve 30 flows into the first outdoor heat exchanger 80 and the second outdoor heat exchanger 70 to condense while exchanging heat with outdoor air.

The refrigerant passing through the first outdoor heat exchanger (80) and the second outdoor heat exchanger (70) passes through the first check valve (43) and the second check valve (53), and in an indoor expansion mechanism (not shown). Expansion. And it is evaporated while passing through the indoor heat exchanger (not shown). At this time, the indoor air, the temperature of which is increased by heat exchange with the refrigerant while passing through the indoor heat exchanger, heats the room. The refrigerant passing through the indoor heat exchanger is introduced into the compressors 11 and 13 again through the four-way valve 30 and the gas-liquid separator 14.

1 is a block diagram showing the flow of the refrigerant during the heating operation of the air conditioner according to the present invention. Referring to Figure 1 will be described the flow of the refrigerant during the heating operation of the air conditioner of the present embodiment.

In the heating operation, the refrigerant is compressed by the compressors 11 and 13 and flows to the four-way valve 30. At this time, the first defrost valve 27 and the second defrost valve 29 are closed so that all of the refrigerant compressed by the compressors 11 and 13 flows to the four-way valve 30. The refrigerant passing through the four-way valve 30 flows into the indoor heat exchanger (not shown) and condenses while exchanging heat with the indoor air.

The refrigerant passing through the indoor heat exchanger (not shown) passes through the indoor expansion mechanism (not shown), and expands while passing through the first expansion valve 41 and the second expansion valve 51. And the refrigerant passing through the first expansion valve 41 is introduced into the first outdoor heat exchanger 80 is evaporated while exchanging heat exchange with the outdoor air blown by the first blower. The refrigerant passing through the second expansion valve 51 flows into the second outdoor heat exchanger 70 and evaporates while exchanging heat with outdoor air blown by the second blower. The refrigerant passing through the first outdoor heat exchanger 80 and the second outdoor heat exchanger 70 passes through the four-way valve 30 and the gas-liquid separator 14 and flows back into the compressors 11 and 13.

2 is a block diagram showing the flow of the refrigerant when the first outdoor heat exchanger 80 performs the defrosting operation.

Referring to FIG. 2, the air conditioner according to the present embodiment performs the heating operation when the first outdoor heat exchanger 80 performs the defrosting operation. Therefore, the first defrost valve 27 is opened, the first expansion valve 41 is opened or closed to the minimum degree.

Specifically, a part of the refrigerant compressed by the compressors 11 and 13 is introduced into the hot gas pipe 20, and the remainder of the refrigerant compressed by the compressors 11 and 13 flows to the four-way valve 30.

The refrigerant flowing into the hot gas pipe 20 passes through the main pipe 21, the first pipe 23, and the first defrost valve 27, and flows into the first outdoor heat exchanger 80 so as to enter the first outdoor heat exchanger. Remove frost conceived at (80). Then, the four-way valve 30 is introduced into the compressors 11 and 13.

The refrigerant passing through the four-way valve 30 is condensed in the indoor heat exchanger (not shown), expanded while passing through the second expansion valve 51, and then evaporated in the second outdoor heat exchanger 70. Passing through the (30) to the compressor (11, 13) to maintain the heating cycle.

4 is a block diagram showing the flow of the refrigerant when the second outdoor heat exchanger 70 performs the defrosting operation. Referring to FIG. 4, when the second outdoor heat exchanger 70 performs a defrosting operation, the first outdoor heat exchanger 80 performs a heating operation. In this case, the flow of the refrigerant is similar to that of the defrosting operation of the first outdoor heat exchanger 80, and thus the description thereof will be omitted.

3 is a block diagram showing the flow of the refrigerant when the second defrost valve is opened before closing the first defrost valve of the first embodiment. In order for the first outdoor heat exchanger 70 to complete the defrosting and to perform the heating operation, the first defrost valve 27 that has been opened must be closed, and the first expansion valve 41 that has been kept at the minimum opening must be opened to the normal opening degree. do.

At this time, the flow pressure of the refrigerant flowing through the hot gas pipe 20 may be caught on the first pipe 23 so that the first defrost valve 27 may not be closed. Therefore, in the present embodiment, the second defrost valve 29 is opened before the first defrost valve 27 is closed. Therefore, the refrigerant flowing through the main pipe 21 temporarily flows through the first pipe 23 and the second pipe 25. As a result, the flow pressure of the refrigerant applied to the main pipe 21 is dispersed into the first pipe 23 and the second pipe 25, and the first defrost valve 27 can be easily closed.

6 is a flowchart showing a defrosting operation method of the air conditioner of the present embodiment. 6, the defrosting operation method of the air conditioner of this embodiment is demonstrated.

In the heating operation step S1, the refrigerant compressed by the compressors 11 and 13 passes through the four-way valve 30 and flows to the indoor heat exchanger, thereby heating the room.

Defrost operation determination step (S2) determines the defrost operation conditions of the outdoor heat exchanger (70, 80) during the heating operation of the air conditioner.

Defrosting operation condition is determined whether the outdoor heat exchanger (70, 80). That is, when moisture is frozen in the outdoor heat exchangers 70 and 80, the heat exchange efficiency of the outdoor heat exchangers 70 and 80 is reduced. In addition, the various measured values in the entire air conditioning cycle of the air conditioner are different from those measured when the outdoor heat exchanger is not implanted. Therefore, whether the outdoor heat exchangers 70 and 80 are implanted can be determined by various measurement values of the air conditioner cooling cycle.

Specifically, in the present embodiment, the outside air temperature passing through the outdoor heat exchangers 70 and 80 is measured by the third temperature sensor 100. The measured value is compared with the previously measured value in normal operation to determine whether it corresponds to the defrosting operation condition.

If the defrosting operation condition corresponds to the first defrost valve 27 is opened (S3). Although not shown in FIG. 6, the opening degree of the first expansion valve 41 is limited to the minimum opening degree. Therefore, most of the refrigerant condensed in the indoor heat exchanger (not shown) flows into the second expansion valve 51.

When the first defrost valve 27 is opened, a part of the refrigerant compressed by the compressors 11 and 13 flows through the main pipe 21 and the first pipe 23 to flow into the first outdoor heat exchanger 80. The first defrosting operation S4 is performed.

Although not shown in FIG. 6, a second portion of the refrigerant compressed in the compressors 11 and 13 in the first defrosting operation S4 is condensed in an indoor heat exchanger (not shown), and then maintained in a normal opening degree. It expands while passing through the expansion valve (51). And after the evaporation in the second outdoor heat exchanger 70 is maintained a heating cycle flowing back to the compressor (11, 13).

In the first defrosting operation determination step (S5), the first temperature sensor 80a measures the refrigerant temperature flowing out of the first outdoor heat exchanger 80 to determine whether the defrost is completed. If the temperature of the refrigerant flowing out does not correspond to the preset temperature, the first defrosting operation S4 is continuously performed.

In addition, when the temperature corresponds to a predetermined temperature, the defrost valve opening step of opening the second defrost valve 29 while the first defrost valve 27 is opened is performed.

Specifically, in the defrost valve opening step of the present embodiment, the second defrost valve 29 is opened (S6). That is, in this embodiment, the first defrost valve 27 and the second defrost valve 29 are simultaneously opened for a predetermined time. Therefore, the flow pressure of the refrigerant passing through the main pipe 21 is distributed to the first pipe 23 and the second pipe 25, so that the first defrost valve 27 can be easily closed.

After the opening of the second defrost valve 29, the first defrost valve 27 is closed after a predetermined time passes (S7). Although not shown in FIG. 6, the first expansion valve 41 is opened at a normal opening in the process of opening the second defrost valve 29 and closing the first defrost valve 27, and the second expansion valve 51. It may include closing the process to the minimum degree. Therefore, most of the refrigerant condensed in the indoor heat exchanger (not shown) flows into the first expansion valve 51.

As a result, when the first defrost valve 27 is closed, only the second defrost valve 29 is opened. Therefore, a part of the refrigerant compressed by the compressors 11 and 13 is performed through the second defrosting operation S8 which flows through the main pipe 21 and the second pipe 25 and flows into the second outdoor heat exchanger 70. do.

Although not shown in FIG. 6, in the second defrosting operation S8, the remaining of the refrigerant compressed by the compressors 11 and 13 is condensed in an indoor heat exchanger (not shown), and then maintained in a normal opening degree. It expands while passing through the expansion valve (41). After the evaporation from the first outdoor heat exchanger (80), the heating cycle flowing into the compressors (11, 13) is maintained.

In the second defrosting operation determination step (S9), the defrosting completion is determined by measuring the refrigerant temperature flowing out of the second outdoor heat exchanger 70 from the second temperature sensor 70a. If the temperature of the refrigerant flowing out does not correspond to the preset temperature, the second defrosting operation S8 is continuously performed.

In addition, when the temperature corresponds to the preset temperature, the defrost valve opening step of opening the first defrost valve 27 is performed while the second defrost valve 29 is opened.

Specifically, in the defrost valve opening step, the first defrost valve 27 is opened (S10). That is, in this embodiment, the first defrost valve 27 and the second defrost valve 29 are simultaneously opened for a predetermined time. Therefore, the flow pressure of the refrigerant passing through the main pipe 21 is distributed to the first pipe 23 and the second pipe 25, so that the first defrost valve 27 and the second defrost valve 29 can be easily closed. It becomes possible.

After opening the first defrost valve 29, when the predetermined time passes, the first defrost valve 27 and the second defrost valve 29 are closed (S7). Although not shown in FIG. 6, the opening degree of the second expansion valve 51 is normally opened in the process of opening the first defrost valve 27 and closing the first defrost valve 27 and the second defrost valve 29. The process may include opening.

As a result, since the defrost of the first outdoor heat exchanger 80 and the second outdoor heat exchanger 70 is completed (S12). In addition, all of the refrigerant compressed by the compressors 11 and 13 flows into the indoor heat exchanger (not shown), and flows through the first expansion valve 41 and the second expansion valve 51 to allow the first outdoor heat exchanger 80 to flow. ) And the second outdoor heat exchanger (70), after which the heating operation flows to the compressors (11, 13) (S13).

7 is a control block diagram for defrosting operation of the air conditioner of the present embodiment.

Referring to FIG. 7, the air conditioner of the present embodiment further includes a controller 200. In addition, the control unit 200 measures the temperature of the outdoor air of the outdoor heat exchangers 70 and 80 or the refrigerant flowing in according to the defrosting operation method of the air conditioner of the present embodiment as described above. Sensing by the first temperature sensor 80a for measuring the temperature of the refrigerant flowing into the outdoor heat exchanger 80 and the second temperature sensor 70a for measuring the temperature of the refrigerant flowing into the second outdoor heat exchanger 70. Compare the value to the normal operation of the air conditioner.

When the controller 200 determines that the outdoor heat exchangers 70 and 80 have been implanted by comparing the values, the control unit 200 according to the defrosting operation method of the air conditioner of the present embodiment described above, Control is performed to open and close the second defrost valve 29, the first expansion valve 41, and the second expansion valve 51.

Second embodiment

8 is a flowchart showing a defrosting operation method of the air conditioner of the second embodiment of the present invention. 8, the defrosting operation method of the air conditioner of this embodiment is demonstrated.

The overall configuration of the air conditioner in this embodiment is the same as in the first embodiment.

Meanwhile, in the first embodiment, it is determined whether the first defrosting is completed in the first defrosting operation step S4 (S5), and the pressure of the refrigerant flowing through the main pipe 21 by opening the second defrost valve 29 is determined. The first pipe 23 and the second pipe 25 are dispersed.

In contrast, in the second embodiment, after the start of the first defrosting operation S24, the second defrost valve 29 is opened after a predetermined time has passed (S25). Therefore, before determining whether the first outdoor heat exchanger 80 has been defrosted (S26), the pressure of the refrigerant flowing through the main pipe 21 by opening the second defrost valve 29 is determined by the first pipe 23 and the first pipe. Disperse into two pipes (25).

In operation S26, it is determined whether the first defrosting operation is completed. When the defrosting of the first outdoor heat exchanger 80 is completed, the first defrost valve 27 is closed (S27) and a second defrosting operation (S28) is performed.

Meanwhile, in the first embodiment, after the second defrosting operation S8, the completion of the second defrosting operation is determined (S9). The first defrost valve 27 is opened to distribute the pressure of the refrigerant flowing through the main pipe 21 to the first pipe 23 and the second pipe 25.

In contrast, in the second embodiment, after the second defrosting operation step S28, the first defrost valve 27 is first opened S29, so that the pressure of the refrigerant flowing through the main pipe 21 is increased in the first pipe 23. And the second pipe 25.

In operation S30, it is determined whether the second defrosting operation is completed. Then, the first defrost valve 27 and the second defrost valve 29 are closed (S31), and the defrosting operation is finished (S32).

That is, in the first embodiment, the closed defrost valve is opened after the completion of the defrosting determination, but in the present embodiment, there is a difference in that it is determined whether the defrost is completed after opening the closed defrost valve. Hereinafter, other operations are the same as those in the first embodiment, and thus description thereof is omitted.

Third embodiment

9 is a block diagram showing the flow of the refrigerant during the defrosting operation of the first outdoor heat exchanger of the third embodiment of the present invention, and FIG. 10 is a view of the second defrost valve and the third defrost valve before closing of the first defrost valve of the third embodiment. 11 is a block diagram showing the flow of the refrigerant during opening, FIG. 11 is a block diagram showing the flow of the refrigerant during the defrosting operation of the second outdoor heat exchanger of the third embodiment, and FIG. 12 is a defrosting operation of the air conditioner of the third embodiment. A flowchart showing the method.

9 to 12, a third embodiment of the present invention will be described.

The air conditioner of the third embodiment of the present invention includes a first outdoor heat exchanger (80), a second outdoor heat exchanger (70) and a third outdoor heat exchanger (90). Therefore, three outdoor expansion mechanisms 40, 50, and 60 and defrost valves 27, 28, and 29 are also provided. Hereinafter, other configurations of the present embodiment are the same as those of the first embodiment, and the descriptions thereof will be omitted.

In the present embodiment, unlike the first embodiment, the three heat exchangers 70, 80, and 90 are sequentially defrosted, and the heat exchanger that does not perform the defrosting operation performs the heating operation. Specifically, the other two outdoor heat exchangers repeat the heating operation while one outdoor heat exchanger performs the defrosting operation. Therefore, in the present embodiment, defrosting operation is performed in three steps unlike the first embodiment.

The heating operation (S41), the defrosting operation determination (S42), the first defrost valve opening (S43), the first defrosting operation step (S44) and the first defrosting completion determination (S45) of the present embodiment are the same as in the first embodiment. Do.

In the defrost valve opening step according to the present embodiment, after the first defrost valve 27 is opened, the second defrost valve 29 and the third defrost valve 28 are opened.

Specifically, when the defrost completion determination of the first outdoor heat exchanger 80 in the first defrost completion determination step (S45), in this embodiment, the second defrost valve 29 and the third defrost valve 28 are opened (S46). ). Therefore, the high pressure refrigerant flowing through the main pipe 21 flows through the first pipe 23, the second pipe 25, and the third pipe 24. As a result, the pressure of the fluid applied to the first pipe 25 at the same time as the opening of the second defrost valve 29 and the third defrost valve 28 is distributed to the second pipe 25 and the third pipe 24. Accordingly, it is easy to close the first defrost valve 27 of the first outdoor heat exchanger 80 having completed defrosting.

In the present embodiment, since the outdoor heat exchangers 70, 80, and 90 are sequentially defrosted, the third defrost valve 28 is closed together with the first defrost valve 27 (S47). Therefore, only the second defrost valve 29 is opened. The high temperature and high pressure refrigerant passing through the main pipe 21 passes through the second pipe 25 and a second defrosting operation step S48 of defrosting the second outdoor heat exchanger 70 is performed.

Since the step after the second defrosting operation S48 is a repetition of the above-described process, a description thereof will be omitted.

On the other hand, in the present embodiment, when it is determined that the third outdoor heat exchanger 90 has completed defrosting in the third defrosting operation determination step S53, all the outdoor heat exchangers 70, 80, and 90 are defrosted. . Then, all the defrost valves 27, 28 and 29 are closed, and all of the refrigerant compressed by the compressors 11 and 13 flows into the indoor heat exchanger (not shown) through the four-way valve 30.

In this process, the first first and second defrost valves 27 and 29 that are closed in the same manner as described above are opened (S54). Therefore, the flow pressure applied to the third pipe 24 is distributed to the first pipe 23 and the second pipe 25. And all the defrost valves 27, 28 and 29 are closed (S55), and defrosting operation is complete | finished (S56).

Fig. 13 is a control block diagram during defrosting operation of the air conditioner of this embodiment.

Referring to FIG. 13, in the present embodiment, as the number of outdoor heat exchangers increases, a temperature sensor for measuring the temperature of the refrigerant flowing out of the third outdoor heat exchanger 90 to determine whether the third defrost operation is completed ( 90a) is added. The third defrost valve 28 and the third expansion valve 61 for controlling the flow of the refrigerant flowing to the third outdoor heat exchanger 90 are added according to the determination of the controller 200. Hereinafter, other configurations will be omitted from the same bar as the control block diagram (Fig. 7) in the first embodiment.

Fourth embodiment

14 is a flowchart of a defrosting operation method of an air conditioner according to a fourth embodiment of the present invention. A defrosting operation method of the air conditioner of the fourth embodiment will be described with reference to FIG.

The overall configuration of this embodiment is the same as that of the third embodiment, and a description thereof will be omitted.

The defrosting operation method of the present embodiment is also the same as that of the third embodiment. However, in the present embodiment, as in the second embodiment, the pressure of the pipe is lowered by opening the valve before determining whether the defrosting operation is completed. When the defrost is determined to be completed, close the defrost valve of the pipe which has completed the defrost.

Specifically, after the start of the first defrosting operation S64, the second defrost valve 29 and the third defrost valve 28 are opened after a predetermined time passes (S65). Therefore, before determining whether the first outdoor heat exchanger 80 has completed defrosting (S66), the pressure of the refrigerant flowing through the main pipe 21 by opening the second defrost valve 29 and the third defrost valve 28 is determined. The first pipe 23, the second pipe 25 and the third pipe 24 are dispersed.

In operation S66, it is determined whether the first defrosting operation is completed. When the first defrosting determination of the first outdoor heat exchanger 80 is completed, the first defrost valve 27 and the third defrost valve 28 are closed (S67) and a second defrosting operation S68 is performed. The following process is omitted as a repetition of the above-described process.

Those skilled in the art will appreciate that the present invention can be embodied in other specific forms without changing the technical spirit or essential features of the present invention. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the scope of the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalent concept are included in the scope of the present invention. Should be interpreted.

1 is a block diagram showing a refrigerant flow of an outdoor unit during heating of an air conditioner according to a first embodiment of the present invention;

2 is a block diagram showing the refrigerant flow of the outdoor unit during the defrosting operation of the first outdoor heat exchanger of the first embodiment;

3 is a block diagram showing the flow of refrigerant when the second defrost valve is opened before closing the first defrost valve of the first embodiment;

4 is a block diagram showing the flow of the refrigerant of the outdoor unit during the defrosting operation of the second outdoor heat exchanger of the first embodiment;

5 is a block diagram showing the flow of the refrigerant of the outdoor unit during cooling of the air conditioner of the first embodiment;

6 is a flowchart showing a defrosting operation method of the air conditioner of the present embodiment;

7 is a control block diagram for defrosting operation of the air conditioner of the present embodiment;

8 is a flowchart showing a defrosting operation method of the air conditioner of the second embodiment of the present invention;

Fig. 9 is a block diagram showing the flow of refrigerant during defrosting operation of the first outdoor heat exchanger of the third embodiment of the present invention;

Fig. 10 is a block diagram showing the flow of refrigerant when the second defrost valve and the third defrost valve are opened before the first defrost valve is closed in the third embodiment;

Fig. 11 is a block diagram showing the flow of refrigerant during defrosting operation of the second outdoor heat exchanger of the third embodiment;

12 is a flowchart showing a defrosting operation method of the air conditioner of the third embodiment;

Fig. 13 is a control block diagram for defrosting of the air conditioner of the third embodiment;

14 is a flowchart showing a defrosting operation method of the air conditioner of the fourth embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

11, 13 compressor 14: gas-liquid separator

16: oil separator 20: hot gas piping

21: main piping 23: first piping

24: 3rd piping 25: 2nd piping

27: first defrost valve 29: second defrost valve

30: four-way valve 40: first outdoor expansion mechanism

41: first expansion valve 43: first check valve

50: second outdoor expansion mechanism 51: second expansion valve

53: second check valve 70: second outdoor heat exchanger

70a: second temperature sensor 80: first outdoor heat exchanger

80a: first temperature sensor 100: third temperature sensor

Claims (10)

A first defrosting operation step of opening a first defrost valve of the first outdoor heat exchanger to start defrosting of the first outdoor heat exchanger; A defrost valve opening step of opening a second defrost valve of a second outdoor heat exchanger after opening the first defrost valve; And A second defrosting operation step of starting a defrosting operation of the second outdoor heat exchanger by closing the first defrosting valve after the second defrosting valve is opened; Defrosting operation method of the air conditioner comprising a. The method according to claim 1, And a first defrosting completion step of determining whether the first outdoor heat exchanger has completed defrosting after the first defrosting operation start step. The defrosting operation method of the air conditioner to perform the step of opening the defrost valve when the defrost completion of the first outdoor heat exchanger is determined in the first defrost operation completion determination step. The method according to claim 1, After the defrost valve opening step, the first defrost completion determination step of determining whether or not the defrost completion of the first outdoor heat exchanger, and The defrosting operation method of the air conditioner for performing the second defrosting operation step, when the defrost completion of the first outdoor heat exchanger is determined in the first defrosting operation completion determination step. The method according to claim 1, In the defrost valve opening step, after the first defrost valve is opened, the second defrost valve of the second outdoor heat exchanger and the third defrost valve of the third outdoor heat exchanger are opened. In the second defrosting operation step, after opening the second defrost valve and the third defrost valve, the defrost of the air conditioner which starts the defrost operation of the second outdoor heat exchanger by closing the first defrost valve and the third defrost valve. How to operate. A second defrosting operation step of opening the second defrost valve of the second outdoor heat exchanger to start defrosting of the second outdoor heat exchanger; A defrost valve opening step of opening the first defrost valve of the first outdoor heat exchanger after opening the second defrost valve; And After the first defrost valve is opened, closing the first defrost valve and the second defrost valve to end the defrosting operation of the first outdoor heat exchanger and the second outdoor heat exchanger; Defrosting operation method of the air conditioner comprising a. The method according to claim 5, And a second defrosting completion step of determining whether defrosting of the second outdoor heat exchanger is completed after the second defrosting operation start step; The defrosting operation method of the air conditioner performing the step of opening the defrost valve when the defrost completion of the second outdoor heat exchanger is determined in the second defrost operation completion determination step. The method according to claim 5, After the defrost valve opening step, the second defrost completion determination step of determining whether the defrost completion of the second outdoor heat exchanger, and The defrosting operation method of the air conditioner to perform the end of the defrosting operation when the defrost completion of the second outdoor heat exchanger is determined in the second defrosting operation completion determination step. The method according to claim 5, In the defrost valve opening step, after the second defrost valve is opened, the second defrost valve of the second outdoor heat exchanger and the third defrost valve of the third outdoor heat exchanger are opened. The defrosting operation end step includes closing the first defrost valve, the second defrost valve, and the third defrost valve after opening the second defrost valve and the third defrost valve, and the first outdoor heat exchanger, the second outdoor heat exchanger, Defrost operation termination step of terminating the defrost operation of the third outdoor heat exchanger; Defrosting operation method of the air conditioner further comprising. A compressor for compressing the refrigerant; A hot gas pipe through which a portion of the refrigerant compressed by the compressor flows; A four-way valve through which the rest of the refrigerant compressed by the compressor flows; An indoor heat exchanger configured to exchange heat with indoor air while the refrigerant passing through the four-way valve flows; An outdoor expansion mechanism in which the refrigerant heat-exchanged in the indoor heat exchanger is expanded; A first heat exchanger in which a defrosting operation is performed while the refrigerant passing through the hot gas pipe flows; A second heat exchanger in which a heating operation is performed while the refrigerant expanded in the outdoor expansion mechanism flows, The hot gas pipe is installed in a first pipe connected to the first outdoor heat exchanger, a second pipe connected to the second outdoor heat exchanger, and the first pipe, and a first defrost valve opened during defrost operation of the first outdoor heat exchanger. And a second defrost valve installed in the second pipe and opened before the first defrost valve is closed. A compressor for compressing the refrigerant; A plurality of outdoor heat exchangers sequentially performing defrosting operation while the refrigerant compressed in the compressor flows; A plurality of pipes connected to the plurality of outdoor heat exchangers such that the refrigerant compressed by the compressor flows to the plurality of outdoor heat exchangers; A plurality of defrost valves respectively installed in the plurality of pipes and partially opened to perform defrosting of the outdoor heat exchanger; An air conditioner that opens at least one of the unopened defrost valves before closing the open defrost valves to reduce pressure in the plurality of pipes.

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