KR101566333B1 - Air conditioner and Defrosting driving method of the same - Google Patents

Abstract

The defrosting operation method of an air conditioner of the present invention includes a first defrosting operation step of opening a first defrosting valve of a first outdoor heat exchanger to start a defrosting operation of a first outdoor heat exchanger, A second defrosting operation step of opening the defrost valve opening step of opening the second defrosting valve of the second outdoor heat exchanger and closing the first defrosting valve and opening the defrosting operation of the second outdoor heat exchanger after opening the second defrosting valve do. The defrost valve of the outdoor heat exchanger that does not perform the defrost operation can be opened to easily close the defrost valve of the outdoor heat exchanger that has completed the defrost operation.

The first outdoor heat exchanger, the second outdoor heat exchanger, the first defrost valve, the second defrost valve

Description

[0001] The present invention relates to an air conditioner and a defrosting driving method of the air conditioner,

The present invention relates to a defrosting operation method of an air conditioner, and more particularly, to a defrosting method of an air conditioner which opens a defrosting valve which is opened before closing of a defrosting valve which is opened among a plurality of defrosting valves, And a driving method.

Background Art [0002] Generally, 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 mechanism, and an indoor heat exchanger. A radiator for cooling the room, and a radiator for heating the room. And a cooling / heating air conditioner for cooling or heating the room.

And 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 when the air conditioner is composed of the air conditioner and the air conditioner. That is, the refrigerant compressed in the compressor during the cooling operation flows through the four-way valve to the outdoor heat exchanger, and the outdoor heat exchanger serves as the 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 in the indoor heat exchanger passes through the four-way valve and flows into the compressor.

On the other hand, the refrigerant compressed in the compressor during the heating operation flows through the four-way valve to the indoor heat exchanger, and the indoor heat exchanger serves as the 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 in the outdoor heat exchanger passes through the four-way valve and flows into the compressor.

In the above-described air conditioner, water is generated on the surface of the heat exchanger serving as an evaporator during operation, and in the case of cooling operation, water is generated on the surface of the outdoor heat exchanger in the case of heating operation on the surface of the indoor heat exchanger. In this case, when the condensed water generated on the surface of the outdoor heat exchanger is frozen at the time of the heating operation, smooth flow of the outdoor air and heat exchange are interrupted and the heating performance is lowered.

Therefore, a recent air conditioner is produced so as to perform a defrost operation for removing the con- densed condensed water. Defrosting operation can be performed in various ways. Some of the outdoor heat exchangers perform the defrosting operation sequentially by using the plurality of outdoor heat exchangers, and the remaining outdoor heat exchangers can supply the indoor air to the room even during the defrosting operation when performing the heating operation. Specifically, a part of the high-pressure refrigerant compressed in the compressor flows to the outdoor heat exchanger performing the defrosting operation, and the rest of the refrigerant compressed in the compressor flows through the indoor heat exchanger and the expansion valve to the outdoor heat exchanger not performing defrost operation And performs a heating operation.

In order to perform the defrost 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. And defrosting operation is performed while sequentially opening and closing the defrost valve connected to the outdoor heat exchanger for 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-described defrosting operation method, in order to sequentially defrost all the outdoor heat exchangers, the defrosting valve of the outdoor heat exchanger having completed the defrosting operation is closed and the defrosting valve of the outdoor heat exchanger performing the defrosting operation is opened. However, in this case, since the pressure of the refrigerant compressed in the compressor is concentrated in the pipe of the outdoor heat exchanger performing the defrosting operation, the defrost valve of the defrosted outdoor heat exchanger is not closed.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide an outdoor heat exchanger which has defrosting operation by opening a defrosting valve of an outdoor heat exchanger which does not perform defrosting operation, And the defrosting operation method of the air conditioner.

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

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

Further, the defrosting operation method of the air conditioner according to the embodiment of the present invention includes a second defrost operation step of opening the second defrost valve of the second outdoor heat exchanger to start the defrosting operation of the second outdoor heat exchanger, A first defrost valve opening step of opening the first defrost valve of the first outdoor heat exchanger after the valve is opened and a second defrost valve closing step of closing the first defrost valve and the second defrost valve, And terminating the defrosting operation of the outdoor heat exchanger.

The air conditioner according to an embodiment of the present invention includes a compressor for compressing refrigerant, a hot gas pipe through which a part of the refrigerant compressed in the compressor flows, a four-way valve through which the remainder of the refrigerant compressed in the compressor flows, An outdoor expansion device in which the refrigerant heat-exchanged in the indoor heat exchanger is expanded, a first heat exchange device in which a defrosting operation is performed while the refrigerant passing through the hot gas pipe flows, And a second heat exchanger in which the refrigerant expanded in the outdoor expansion mechanism flows and a heating operation is performed. The hot gas piping includes a first pipe connected to the first outdoor heat exchanger, a second pipe connected to the second outdoor heat exchanger, a first pipe installed in the first pipe and opened during a defrosting 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.

The air conditioner according to an embodiment of the present invention further includes a compressor for compressing the refrigerant, a plurality of outdoor heat exchangers for sequentially performing the defrost operation while the refrigerant compressed in the compressor flows, a plurality of outdoor heat exchangers And a plurality of defrost valves respectively installed in the plurality of pipes and partially opened to perform the defrosting operation of the outdoor heat exchanger. And at least one of the defrost valves not opened before closing the defrosting valve is opened to reduce the pressure of the plurality of piping.

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

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

There is an effect that the pressure of the piping connecting the outdoor heat exchanger and the compressor which performs the defrosting operation by opening the defrost valve of the outdoor heat exchanger not performing the defrosting operation is reduced. Accordingly, the defrost valve can be easily closed when the defrosting operation of the outdoor heat exchanger performing the defrosting operation is completed, and the defrost valve can be prevented from being damaged due to excessive flow pressure in the process of closing the defrosting valve.

Further, the control of the defrosting valve according to the defrosting completion can be made precise, and the defrosting efficiency and the heating efficiency can be increased.

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

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

First Embodiment

FIG. 1 is a configuration diagram showing a refrigerant flow in an outdoor unit when the air conditioner according to the first embodiment of the present invention is heated. FIG. 2 is a view showing a refrigerant flow in the outdoor unit during the first outdoor heat exchanger defrosting operation in the first embodiment Fig. 3 is a configuration diagram showing the flow of the refrigerant when the second defrost valve is opened before closing the first defrost-preventive valve of the first embodiment, Fig. 4 is a view showing the flow of the refrigerant when the defrosting operation of the second outdoor heat exchanger of the first embodiment Fig. 8 is a configuration diagram showing the flow of refrigerant in an outdoor unit. The overall configuration of the air conditioner of this embodiment will be described with reference to Figs. 1 to 4. Fig.

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 a plurality of indoor units are installed at a plurality of places where the user wants to cool and / or heat.

Referring to FIG. 1, the outdoor unit of the air conditioner of the present 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.

The compressors (11, 13) compress the refrigerant. Any one of the compressors 11 and 13 may be composed of a variable capacity compressor such as an inverter compressor and the other may be a constant speed compressor. A gas-liquid separator (14) is connected to the suction side of the compressors (11, 13), and an oil separator (16) and a check valve are provided on the discharge side.

A part of the refrigerant compressed in the compressors (11, 13) flows in the hot gas piping (20). Particularly, a part of the high-temperature and high-pressure refrigerant compressed by the compressors 11 and 13 during the defrosting operation flows into the outdoor heat exchangers 80 and 90 through the hot gas piping 20 and flows into the outdoor heat exchangers 80 and 90 Defeats.

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

A portion of the refrigerant compressed in the compressors (11, 13) flows through the main pipe (21). And may be connected to the piping between the indoor heat exchangers (not shown) of the four-way valve 30. However, in the present embodiment, one side of the main pipe 21 is connected between the compressors 11 and 13 and the four-way valve 30. [ Therefore, the pressure loss of the refrigerant can be reduced as compared with a case where the refrigerant compressed in the compressors 11 and 13 flows to the main pipe 21 after passing through the four-way valve 30. [ The other side of the main piping 21 is connected to the first piping 23 and the second piping 25, which will be described later. Therefore, the refrigerant that has passed 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. During the defrosting operation of the first outdoor heat exchanger (80), the first defrost valve (27) is opened. Accordingly, the high-temperature and high-pressure refrigerant compressed by the compressors 11 and 13 flows 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 piping 25 communicates 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. During the defrosting operation of the second outdoor heat exchanger (70), the second defrost valve (29) is opened. Accordingly, the high-temperature and high-pressure refrigerant compressed by the compressors 11 and 13 flows 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.

On the other hand, in the present embodiment, the second outdoor heat exchanger (70) performs the heating operation during the defrosting operation of the first outdoor heat exchanger (80). Therefore, in this case, 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, so that the first outdoor heat exchanger 80 performs the heating operation, 2 outdoor heat exchanger 70 performs the defrost operation.

Here, the refrigerant compressed by the compressors (11, 13) during the defrosting operation of the first outdoor heat exchanger (80) flows only through the first pipe (23). Accordingly, the flow pressure of the flow refrigerant is fully applied to the first pipe 23. A phenomenon that the first defrost valve 27 is not closed by the flow pressure occurs. Therefore, in this embodiment, the first and second defrost valves 27 and 29 are temporarily opened simultaneously before the first defrost valve 27 is closed. Accordingly, the flow pressure of the refrigerant compressed by the compressors 11 and 13 is dispersed in 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 changes the flow direction of the refrigerant according to the cooling / heating operation of the air conditioner. That is, the refrigerant evaporated in the indoor heat exchanger (not shown) flows to the compressors 11 and 13 during the cooling operation, and the refrigerant compressed in the compressor flows to the outdoor heat exchangers 70 and 80. During the heating operation, the refrigerant evaporated in the outdoor heat exchangers (70, 80) flows to the compressors (11, 13) side, 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 exchangers 70 and 80 flows to the compressors 11 and 13, and the refrigerant, which has not flowed to the main pipe 21 among the refrigerants compressed in the compressors 11 and 13, And flows into a heat exchanger (not shown).

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

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

The number of the outdoor expansion mechanisms (40, 50) corresponds to the number of the outdoor heat exchangers (70, 80). The outdoor expansion mechanism 40 or 50 includes a first outdoor expansion mechanism 40 connected to the first outdoor heat exchanger 80 and a second outdoor expansion mechanism 50 connected to the second outdoor heat exchanger 70, . Specifically, the expansion valves 41 and 51 in this embodiment are constituted by an electronic expansion valve, and the opening degree of the electronic expansion valve is limited to the minimum opening degree in the defrosting operation of each of the outdoor heat exchangers 70 and 80, Thereby preventing the refrigerant from flowing into the heat exchanger (70, 80).

The plurality of outdoor heat exchangers (70, 80) condenses / evaporates the refrigerant flowing using the outdoor air flowing. During the defrosting operation, the refrigerant compressed by the compressor in the compressors (11, 13) flows and the water impregnated in the outdoor heat exchangers (70, 80) is removed.

The outdoor heat exchangers 70 and 80 may be provided in various numbers, but in the present embodiment, the first outdoor heat exchanger 80 and the second outdoor heat exchanger 70 are included. During the cooling operation, the refrigerant flowing in the first outdoor heat exchanger (80) and the second outdoor heat exchanger (70) is condensed by the outdoor air. During the heating operation, the refrigerant flowing in the first outdoor heat exchanger (80) and the second outdoor heat exchanger (70) is evaporated by the outdoor air.

In the defrosting operation, the defrosting operation is performed in the first outdoor heat exchanger (80) while the refrigerant passing through the compressors (11, 13), the main pipe (21) and the first pipe (27) flows. At this time, the refrigerant passing through the second outdoor expansion valve (51) flows into the second outdoor heat exchanger (70), and the heating operation is performed. As a result, in the present invention, some of the plurality of outdoor heat exchangers (70, 80) perform the defrosting operation and the rest of the outdoor heat exchangers (70, 80) perform the heating operation. It is possible to continuously supply heated air to the room while performing the defrosting operation.

The first outdoor heat exchanger 80 and the first temperature sensor 80a are installed in the second outdoor heat exchanger 70 and the second temperature sensor 80a is installed in the outdoor heat exchangers 70 and 80, The temperature of the refrigerant is measured. The outdoor heat exchangers 70 and 80 are provided with an additional third temperature sensor 100 to measure the temperature of the refrigerant flowing into the outdoor heat exchangers 70 and 80 and the temperature of the outdoor air. In order to determine whether defrosting has occurred, the temperature of outdoor air passing through the outdoor heat exchangers 70, 80 can be measured.

The operation of the first embodiment of the air conditioner of the present invention constructed as above and the defrosting operation method will be described as follows.

FIG. 5 is a view showing the flow of a refrigerant during a cooling operation of the air conditioner according to the present invention. The flow of the refrigerant during the cooling operation of the air conditioner of the present embodiment will be described with reference to FIG.

During the cooling operation, the refrigerant is compressed by the compressors (11, 13) and flows to the four-way valve (30). At this time, the first and second defrost valves 27 and 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 that has passed through the four-way valve 30 flows into the first outdoor heat exchanger 80 and the second outdoor heat exchanger 70 and is heat-exchanged with the outdoor air to be condensed.

The refrigerant having passed 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 flows through the indoor expansion mechanism It becomes swollen. And evaporated while passing through an indoor heat exchanger (not shown). At this time, the indoor air having the temperature raised by the heat exchange with the refrigerant while passing through the indoor heat exchanger, heats the room. The refrigerant having passed through the indoor heat exchanger passes through the four-way valve 30 and the gas-liquid separator 14 and flows into the compressors 11 and 13 again.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a configuration diagram showing a flow of a refrigerant during a heating operation of an air conditioner according to the present invention; FIG. The flow of the refrigerant in the heating operation of the air conditioner of the present embodiment will be described with reference to FIG.

During the heating operation, the refrigerant is compressed by the compressors (11, 13) and flows to the four-way valve (30). At this time, the first and second defrost valves 27 and 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 that has passed through the four-way valve 30 flows into the indoor heat exchanger (not shown), and is heat-exchanged with the room air to be condensed.

The refrigerant that has passed through the indoor heat exchanger (not shown) passes through an indoor expansion mechanism (not shown) and expands while passing through the first expansion valve 41 and the second expansion valve 51. The refrigerant having passed through the first expansion valve (41) flows into the first outdoor heat exchanger (80) and is evaporated while exchanging heat with the outdoor air blown by the first blower. The refrigerant having passed through the second expansion valve (51) flows into the second outdoor heat exchanger (70) and evaporates while exchanging heat with the outdoor air blown by the second blower. The refrigerant having passed 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 into the compressors 11 and 13 again.

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

Referring to FIG. 2, in the air conditioner of the present embodiment, when the first outdoor heat exchanger 80 performs the defrosting operation, the second outdoor heat exchanger 70 performs the heating operation. Therefore, the first defrost valve 27 is opened, and the first expansion valve 41 is opened or closed at the minimum opening degree.

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

The refrigerant flowing into the hot gas pipe 20 flows into the first outdoor heat exchanger 80 through the main pipe 21, the first pipe 23 and the first defrost valve 27, Thereby removing the frost that has been conceived on the heat exchanger 80. And flows into the compressors (11, 13) through the four-way valve (30).

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

4 is a view 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 the defrost operation, the first outdoor heat exchanger 80 performs the 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 a description thereof will be omitted.

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

At this time, the flow pressure of the refrigerant flowing through the hot gas pipe 20 may be caught by the first pipe 23, so that the first defrost valve 27 may not be closed. Therefore, in this embodiment, the second defrost valve 29 is opened before the first defrost valve 27 is closed. Accordingly, the refrigerant flowing through the main pipe 21 temporarily flows through the first pipe 23 and the second pipe 25. [ Consequently, the flow pressure of the refrigerant applied to the main pipe 21 is dispersed in the first pipe 23 and the second pipe 25, so that the first valve 22 can be easily closed.

6 is a flowchart showing the defrosting operation method of the air conditioner of the present embodiment. The defrosting operation method of the air conditioner of the present embodiment will be described with reference to Fig.

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

The defrosting operation determination step S2 determines defrosting conditions of the outdoor heat exchangers 70 and 80 during the heating operation of the air conditioner.

The defrosting operation condition is determined based on whether or not the outdoor heat exchangers (70, 80) are concealed. That is, when water is frozen in the outdoor heat exchangers 70 and 80, the heat exchange efficiency of the outdoor heat exchangers 70 and 80 is lowered. In the entire cooling cycle of the air conditioner, various measured values are different from the measured values when the outdoor heat exchanger is not conceived. Thus, whether or not the outdoor heat exchangers 70 and 80 are fusing can be judged by various measured values of the air conditioner cooling cycle.

Specifically, in this embodiment, the outdoor temperature passed through the outdoor heat exchangers (70, 80) is measured by the third temperature sensor (100). Then, the measured value is compared with the measured value at the time of normal operation to determine whether it corresponds to the defrosting operation condition.

When the defrosting operation condition is satisfied, 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 in the compressors 11 and 13 flows into the main pipe 21 and the first pipe 23 and flows into the first outdoor heat exchanger 80 1 defrosting operation step S4 is performed.

6, the remainder of the refrigerant compressed in the compressors 11 and 13 in the first defrost operation step S4 is condensed in the indoor heat exchanger (not shown) And is expanded while passing through the expansion valve (51). Then, the refrigerant is evaporated in the second outdoor heat exchanger (70), and then the heating cycle, which flows into the compressors (11, 13), is maintained.

In the first defrosting operation completion determination step S5, the first temperature sensor 80a measures the temperature of the refrigerant flowing out of the first outdoor heat exchanger 80 to determine whether defrosting has been completed. If the temperature of the outflow refrigerant does not correspond to the predetermined temperature, the first defrosting operation step (S4) is continued.

When the predetermined temperature is reached, a defrost valve opening step for opening the second defrost valve 29 in a state where the first defrost valve 27 is opened is performed.

Specifically, in the defrost valve opening step of this embodiment, the second defrost valve 29 is opened (S6). That is, in this embodiment, the first and second defrost valves 27 and 29 are opened simultaneously for a predetermined period of time. The flow pressure of the refrigerant flowing through the main pipe 21 is dispersed to the first pipe 23 and the second pipe 25 so that the first valve 22 can be easily closed.

After the second defrosting valve 29 is opened, the first defrosting valve 27 is closed (S7). 6, the first expansion valve 41 is opened at a normal opening degree in the process of opening the second defrost valve 29 and closing the first defrost valve 27, and the second expansion valve 51 is opened, May be closed at the minimum opening 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. A second defrost operation step S8 in which a part of the refrigerant compressed in the compressors 11 and 13 flows into the second outdoor heat exchanger 70 through the main piping 21 and the second piping 25 is performed do.

Although not shown in FIG. 6, in the second defrost operation step S8, the remainder of the refrigerant compressed by the compressors 11 and 13 is condensed in the indoor heat exchanger (not shown) And is expanded while passing through the expansion valve (41). Then, the refrigerant is evaporated in the first outdoor heat exchanger (80), and then the heating cycle flowing into the compressors (11, 13) is maintained.

In the second defrosting operation completion determination step S9, the second temperature sensor 70a measures the temperature of the refrigerant flowing out of the second outdoor heat exchanger 70 to determine whether defrosting has been completed. If the temperature of the outflow refrigerant does not correspond to the predetermined temperature, the second defrosting operation step (S8) continues.

When the predetermined temperature is reached, a defrost valve opening step for opening the first defrost valve 27 with the second defrost valve 29 opened is performed.

Specifically, in the defrosting valve opening step, the first defrosting valve 27 is opened (S10). That is, in this embodiment, the first and second defrost valves 27 and 29 are opened simultaneously for a predetermined period of time. The flow pressure of the refrigerant flowing through the main pipe 21 is dispersed in the first pipe 23 and the second pipe 25 and the first and second defrost valves 27 and 29 are easily closed .

After the first defrost valve 29 is opened, the first defrost valve 27 and the second defrost valve 29 are closed (S7). Although not shown in FIG. 6, in the process of opening the first and second defrost valves 27 and 29, the opening degree of the second expansion valve 51 is set to a normal opening degree As shown in FIG.

As a result, since defrosting of the first outdoor heat exchanger 80 and the second outdoor heat exchanger 70 is completed, the defrosting operation is terminated (S12). All of the refrigerant compressed in the compressors 11 and 13 flows into the indoor heat exchanger (not shown), flows through the first expansion valve 41 and the second expansion valve 51 and flows into the first outdoor heat exchanger 80 ) And the second outdoor heat exchanger (70), and then flows to the compressors (11, 13) for heating operation (S13).

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

Referring to FIG. 7, the air conditioner of the present embodiment further includes a control unit 200. The control unit 200 includes a third temperature sensor 100 for measuring the temperature of the outdoor air or the refrigerant flowing in the outdoor heat exchangers 70 and 80 according to the defrosting method of the air conditioner of the present embodiment, 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 And the value of the normal operation of the air conditioner is compared.

When it is determined that the outdoor heat exchangers 70 and 80 have been conceived, the controller 200 controls the first defrost valve 27 and the second defrost valve 27 in accordance with the defrosting method of the air conditioner of the present embodiment, 2 defrost valve 29, the first expansion valve 41, and the second expansion valve 51 are controlled to be opened and closed.

Second Embodiment

8 is a flowchart showing a defrosting operation method of the air conditioner of the second embodiment of the present invention. The defrosting operation method of the air conditioner of this embodiment will be described with reference to Fig.

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

On the other hand, in the first embodiment, it is determined whether or not the first defrosting has been completed in the first defrosting operation step (S4), and the pressure of the refrigerant flowing through the main piping 21 by opening the second defrosting valve (29) And is dispersed in the first pipe 23 and the second pipe 25.

In contrast, in the second embodiment, the second defrost valve 29 is opened (S25) after a predetermined time elapses after the first defrosting operation S24 starts. Therefore, before determining whether the defrosting of the first outdoor heat exchanger 80 has been completed (S26), the second defrost valve 29 is opened to apply the pressure of the refrigerant flowing through the main pipe 21 to the first pipe 23 and the second pipe 23, 2 pipe (25).

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

On the other hand, in the first embodiment, it is determined that the second defrosting operation has been completed (S9) after the second defrosting operation step (S8). 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.

On the other hand, in the second embodiment, the first defrost valve 27 is first opened (S29) after the second defrost operation step S28, and the pressure of the refrigerant flowing through the main pipe 21 is set to the first pipe 23, And the second pipe (25).

Then, it is determined whether the second defrost operation has been completed (S30). Then, the first and second defrost valves 27 and 29 are closed (S31), and the defrosting operation is terminated (S32).

That is, in the first embodiment, the closed defrosting valve is opened after the defrosting completion determination, but the present embodiment differs from the first embodiment in that the closed defrosting valve is opened and then the defrosting completion is determined. Other functions are the same as those in the first embodiment, and a description thereof will be omitted.

Third Embodiment

FIG. 9 is a view showing the flow of the refrigerant in the defrosting operation of the first outdoor heat exchanger of the third embodiment of the present invention, and FIG. 10 is a view showing a state in which the second defrost valve and the third defrost valve Fig. 11 is a configuration diagram showing the flow of the refrigerant during the defrosting operation of the second outdoor heat exchanger of the third embodiment, Fig. 12 is a view showing the defrosting operation of the air conditioner of the third embodiment Fig.

A third embodiment of the present invention will be described with reference to Figs. 9 to 12. Fig.

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, 60) and defrost valves (27, 28, 29) are also provided. Hereinafter, the other structures of the present embodiment are the same as those of the first embodiment, and a description thereof will be omitted.

In this embodiment, unlike the first embodiment, the three outdoor heat exchangers 70, 80, and 90 perform the defrosting operation while sequentially performing the defrosting operation. Specifically, while one outdoor heat exchanger performs the defrost operation, the other two outdoor heat exchangers repeat the heating operation. Therefore, in this embodiment, the defrosting operation is performed in three stages unlike the first embodiment.

The steps of heating operation S41, defrosting operation judgment S42, first defrosting valve opening S43, first defrosting operation S44 and first defrosting completion determination S45 of this embodiment are the same as those of the first embodiment Do.

The defrost valve opening step in this embodiment opens the second defrost valve 29 and the third defrost valve 28 after the first defrost valve 27 is opened.

Specifically, when the defrosting completion of the first outdoor heat exchanger 80 is determined in the first defrosting completion determining step S45, the second defrosting valve 29 and the third defrosting valve 28 are opened in this embodiment (S46 ). Accordingly, 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. [ At the same time as the second and third defrost valves 29 and 28 are opened, the pressure of the fluid in the first pipe 25 is dispersed in the second pipe 25 and the third pipe 24. Therefore, it is easy to close the first defrost valve 27 of the defrosted first outdoor heat exchanger 80.

In this embodiment, the third defrost valve 28 is closed together with the first defrost valve 27 to sequentially defrost the outdoor heat exchangers 70, 80, and 90 (S47). Therefore, only the second defrost valve 29 is opened. The second high temperature and high pressure refrigerant that has passed through the main pipe 21 passes through the second pipe 25 and performs a second defrost operation step S48 for defrosting the second outdoor heat exchanger 70. [

The steps after the second defrosting operation step (S48) are the repetition of the process described above, and a description thereof will be omitted.

On the other hand, if it is determined in the third defrosting operation determining step (S53) that the defrosting of the third outdoor heat exchanger 90 is completed, the defrosting of all the outdoor heat exchangers (70, 80, 90) is completed . Then, all of 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 and second defrosting valves 27 and 29, which are closed 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. Then, all the defrost valves 27, 28 and 29 are closed (S55), and the defrosting operation is terminated (S56).

13 is a control block diagram in the defrosting operation of the air conditioner of the present embodiment.

Referring to FIG. 13, in this embodiment, a temperature sensor (not shown) for measuring the temperature of the refrigerant flowing out of the third outdoor heat exchanger 90 for determining whether the third defrosting operation is completed as the number of the outdoor heat exchangers increases 90a are added. The third defrost valve 28 and the third expansion valve 61 are added to control the flow of the refrigerant flowing to the third outdoor heat exchanger 90 according to the judgment of the controller 200. [ The other configurations are the same as those in the control block diagram (Fig. 7) in the first embodiment, and the description thereof is omitted.

Fourth Embodiment

14 is a flowchart of a defrost operation method of an air conditioner according to a fourth embodiment of the present invention. The 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 generally the same as that of the third embodiment. However, in this embodiment, as in the second embodiment, the valve is opened to lower the pressure of the pipe before determining whether the defrosting operation is completed or not. If it is judged that the defrosting has been completed, the defrosting valve of the defrosted pipe is closed.

Specifically, after the start of the first defrosting operation step S64, the second defrost valve 29 and the third defrost valve 28 are opened (S65) after a predetermined time has elapsed. The second defrosting valve 29 and the third defrosting valve 28 are opened to determine the pressure of the refrigerant flowing through the main piping 21 The first piping 23, the second piping 25 and the third piping 24. As shown in Fig.

Then, it is determined whether the first defrost operation has been completed (S66). When the defrosting completion of the first outdoor heat exchanger 80 is determined, the first defrost valve 27 and the third defrost valve 28 are closed (S67) and the second defrost operation step S68 is performed. The following process is repeated as described above.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. 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 defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalents thereof are included in the scope of the present invention Should be interpreted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a flow of a refrigerant in an outdoor unit when the air conditioner is heated according to the first embodiment of the present invention; FIG.

2 is a view showing the flow of refrigerant in an outdoor unit during the first outdoor heat exchanger defrosting operation of the first embodiment;

3 is a view showing the flow of the refrigerant when the second defrost valve is opened before the first defrost valve closed in the first embodiment;

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

5 is a view showing a flow of a refrigerant in an outdoor unit during cooling of the air conditioner of the first embodiment;

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

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

8 is a flowchart showing a defrost operation method of an air conditioner according to a second embodiment of the present invention;

9 is a view showing a flow of a refrigerant in a defrosting operation of a first outdoor heat exchanger of a third embodiment of the present invention;

10 is a view showing the flow of the refrigerant at the time of opening the second defrost valve and the third defrost valve before closing the first defrost valve in the third embodiment;

11 is a view showing the flow of the refrigerant during the 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;

13 is a control block diagram of the air conditioner of the third embodiment;

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

Description of the Related Art

11, 13: Compressor 14: Gas-liquid separator

16: Oil separator 20: Hot gas piping

21: main piping 23: first piping

24: Third piping 25: Second 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 (15)

delete A first defrost operation step of opening the first defrost valve of the first outdoor heat exchanger to start defrosting operation of the first outdoor heat exchanger; A first defrosting completion judging step of judging whether defrosting of the first outdoor heat exchanger has been completed after the first defrosting operation step; A defrost valve opening step of opening the second defrost valve of the second outdoor heat exchanger when the defrosting completion of the first outdoor heat exchanger is determined in the first defrost operation completion judgment step; And And a second defrost operation step of starting the defrosting operation of the second outdoor heat exchanger by closing the first defrost valve after a predetermined time after the second defrost valve is opened. A first defrost operation step of opening the first defrost valve of the first outdoor heat exchanger to start defrosting operation of the first outdoor heat exchanger; A defrost valve opening step of opening the second defrost valve of the second outdoor heat exchanger after the first defrost valve is opened; A first defrosting completion judging step of judging whether the defrosting of the first outdoor heat exchanger is completed after the defrost valve opening step; And And a second defrosting operation step of closing the first defrost valve and initiating a defrosting operation of the second outdoor heat exchanger when the defrosting completion of the first outdoor heat exchanger is determined in the first defrosting completion determination step How to operate defroster defroster. A first defrost operation step of opening the first defrost valve of the first outdoor heat exchanger to start defrosting operation of the first outdoor heat exchanger; A defrost valve opening step of opening the second defrost valve of the second outdoor heat exchanger and the third defrost valve of the third outdoor heat exchanger after the first defrost valve is opened; And And a second defrost operation step of closing the first defrost valve and the third defrost valve and opening the defrosting operation of the second outdoor heat exchanger after the second defrost valve and the third defrost valve are opened, Defrosting operation method. A second defrost operation step of opening the second defrost valve of the second outdoor heat exchanger to start defrosting operation of the second outdoor heat exchanger; A defrost valve opening step of opening the first defrost valve of the first outdoor heat exchanger after the second defrost valve is opened; And And a defrosting termination step of closing the first defrost valve and the second defrost valve and terminating the defrosting operation of the first outdoor heat exchanger and the second outdoor heat exchanger after the first defrost valve is opened, Defrosting operation method. The method of claim 5, And a second defrosting operation completion determining step of determining whether the defrosting of the second outdoor heat exchanger has been completed after the second defrost operation, And performing the defrost valve opening step when the defrosting completion determination of the second outdoor heat exchanger is performed in the second defrosting completion determination step. The method of claim 5, And a second defrosting completion judging step of judging whether or not the defrosting of the second outdoor heat exchanger has been completed after the defrosting valve opening step, And performing the defrosting termination step upon the defrosting completion determination of the second outdoor heat exchanger in the second defrosting completion determination step. A second defrost operation step of opening the second defrost valve of the second outdoor heat exchanger to start defrosting operation of the second outdoor heat exchanger; A defrost valve opening step of opening the first defrost valve of the first outdoor heat exchanger and the third defrost valve of the third outdoor heat exchanger after the second defrost valve is opened; And The first defrost valve, the second defrost valve, and the third defrost valve are closed after the first and second defrost valves are opened, and the first outdoor heat exchanger, the second outdoor heat exchanger, And terminating the defrosting operation of the outdoor heat exchanger. A compressor for compressing the refrigerant; A hot gas pipe through which a part of the refrigerant compressed in the compressor flows; A four-way valve in which the remainder of the refrigerant compressed in the compressor flows; An indoor heat exchanger for exchanging 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 outdoor heat exchanger in which a defrost operation is performed while a refrigerant passing through the hot gas pipe flows; And a second outdoor heat exchanger in which the refrigerant expanded in the outdoor expansion mechanism flows and a heating operation is performed, The hot gas piping includes a first pipe connected to the first outdoor heat exchanger, a second pipe connected to the second outdoor heat exchanger, a first defrost valve installed in the first pipe, and a second defrost valve installed in the second pipe, Lt; / RTI > And a controller for controlling the first and second defrost valves, Wherein the control unit opens the first defrost valve and closes the second defrost valve to start the defrosting operation of the first outdoor heat exchanger and when the defrosting of the first outdoor heat exchanger is completed, And the defrosting operation of the second outdoor heat exchanger is started by closing the first defrost valve when a predetermined time has elapsed after the second defrost valve is opened. A compressor for compressing the refrigerant; A hot gas pipe through which a part of the refrigerant compressed in the compressor flows; A four-way valve in which the remainder of the refrigerant compressed in the compressor flows; An indoor heat exchanger for exchanging 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 outdoor heat exchanger in which a defrost operation is performed while a refrigerant passing through the hot gas pipe flows; And a second outdoor heat exchanger for performing a heating operation while the refrigerant expanded in the outdoor expansion mechanism flows, The hot gas piping includes a first pipe connected to the first outdoor heat exchanger, a second pipe connected to the second outdoor heat exchanger, a first defrost valve installed in the first pipe, and a second defrost valve installed in the second pipe, Lt; / RTI > And a controller for controlling the first and second defrost valves, Wherein the control unit opens the first defrost valve and closes the second defrost valve to start the defrosting operation of the first outdoor heat exchanger and before the defrosting of the first outdoor heat exchanger is completed, And the defrosting operation of the second outdoor heat exchanger is started by closing the first defrost valve when defrosting of the first outdoor heat exchanger is completed. A compressor for compressing the refrigerant; A hot gas pipe through which a part of the refrigerant compressed in the compressor flows; A four-way valve in which the remainder of the refrigerant compressed in the compressor flows; An indoor heat exchanger for exchanging 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 outdoor heat exchanger in which a defrost operation is performed while a refrigerant passing through the hot gas pipe flows; A second outdoor heat exchanger for performing a heating operation while the refrigerant expanded in the outdoor expansion mechanism flows; And a third outdoor heat exchanger for performing a heating operation while the refrigerant expanded in the outdoor expansion mechanism flows, The hot gas piping includes a first pipe connected to the first outdoor heat exchanger, a second pipe connected to the second outdoor heat exchanger, a third pipe connected to the third outdoor heat exchanger, a first defrost valve installed in the first pipe, A second defrost valve disposed in the second pipe, and a third defrost valve disposed in the third pipe, Further comprising a control section for controlling said first defrost valve, said second defrost valve and said third defrost valve, Wherein the control unit opens the first defrost valve and closes the second defrost valve and the third defrost valve to start the defrosting operation of the first outdoor heat exchanger, the second defrost valve and the third defrost valve And then the first defrost valve and the third defrost valve are closed to start the defrosting operation of the second outdoor heat exchanger. A compressor for compressing the refrigerant; A hot gas pipe through which a part of the refrigerant compressed in the compressor flows; A four-way valve in which the remainder of the refrigerant compressed in the compressor flows; An indoor heat exchanger for exchanging 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 outdoor heat exchanger in which a defrost operation is performed while a refrigerant passing through the hot gas pipe flows; And a second outdoor heat exchanger for performing a heating operation while the refrigerant expanded in the outdoor expansion mechanism flows, The hot gas piping includes a first pipe connected to the first outdoor heat exchanger, a second pipe connected to the second outdoor heat exchanger, a first defrost valve installed in the first pipe, and a second defrost valve installed in the second pipe, Lt; / RTI > And a controller for controlling the first and second defrost valves, Wherein the control unit closes the first defrost valve and opens the second defrost valve to start the defrosting operation of the second outdoor heat exchanger and then opens the first defrost valve, 2 defrost valve is closed to terminate the defrosting operation of the first outdoor heat exchanger and the second outdoor heat exchanger. The method of claim 12, Wherein the control unit opens the first defrost valve when the defrosting of the second outdoor heat exchanger is completed after the defrosting operation of the second outdoor heat exchanger is started and then the first defrost valve and the second defrost valve And closes the defrosting operation of the first outdoor heat exchanger and the second outdoor heat exchanger. The method of claim 12, Wherein the controller opens the first defrost valve before the defrosting of the second outdoor heat exchanger is completed after the defrosting operation of the second outdoor heat exchanger is started and when the defrosting of the second outdoor heat exchanger is completed, The first defrost valve and the second defrost valve are closed to terminate the defrosting operation of the first outdoor heat exchanger and the second outdoor heat exchanger. A compressor for compressing the refrigerant; A hot gas pipe through which a part of the refrigerant compressed in the compressor flows; A four-way valve in which the remainder of the refrigerant compressed in the compressor flows; An indoor heat exchanger for exchanging 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 outdoor heat exchanger in which a defrost operation is performed while a refrigerant passing through the hot gas pipe flows; A second outdoor heat exchanger for performing a heating operation while the refrigerant expanded in the outdoor expansion mechanism flows; And a third outdoor heat exchanger for performing a heating operation while the refrigerant expanded in the outdoor expansion mechanism flows, The hot gas piping includes a first pipe connected to the first outdoor heat exchanger, a second pipe connected to the second outdoor heat exchanger, a third pipe connected to the third outdoor heat exchanger, a first defrost valve installed in the first pipe, A second defrost valve disposed in the second pipe, and a third defrost valve disposed in the third pipe, Further comprising a control section for controlling said first defrost valve, said second defrost valve and said third defrost valve, Wherein the control unit opens the second defrost valve and closes the first defrost valve and the third defrost valve to start the defrosting operation of the second outdoor heat exchanger so that the first defrost valve and the third defrost valve The second defrosting valve and the third defrosting valve to close the first defrosting valve, the second defrosting valve, and the third defrosting valve, and to stop the defrosting operation of the first outdoor heat exchanger, the second outdoor heat exchanger and the third outdoor heat exchanger Harmonics.

Images