KR20100096553A - Air conditioner and defrosting driving method of the same - Google Patents

Abstract

PURPOSE: An air conditioner and a defrosting method thereof are provided to increase the defrosting efficiency of an outdoor heat exchanger by changing the amount of refrigerant flowing to an outdoor heat exchanger performing a defrosting operation by decreasing the opening degree of an indoor expansion valve. CONSTITUTION: If a defrosting condition is satisfied, a defrosting valve is opened and a part of the refrigerant compressed by a compressor flows into an outdoor heat exchanger(S1). It is determined whether the temperature of the outdoor heat exchanger has reached a defrosting end temperature(S2). If not, the opening degree of the indoor expansion valve of the indoor heat exchanger is closed by a first predetermined degree(S3). It is determined whether the opening degree of the indoor expansion valve closed by the first predetermined degree has reached the minimum opening degree(S4). If yes, 'the opening of the indoor expand valve shut by the first setting ratio' arrives in to the minimum opening. It is determined whether the temperature of the outdoor heat exchanger has reached the defrosting end temperature(S5). If not, The temperature of the outdoor heat exchanger does not arrive in to the defrost extrication temperature. The defrosting valve is closed (S7).

Description

Air conditioner and Defrosting driving method of the same}

The present invention relates to an air conditioner and a defrosting operation method of the air conditioner, and more particularly, after monitoring the temperature of the outdoor heat exchanger during the defrosting operation, the refrigerant flowing to the outdoor heat exchanger during the defrosting operation by adjusting the indoor expansion valve. The present invention relates to an air conditioner and a defrosting operation method of an air conditioner for increasing the amount of defrosting efficiency.

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 in 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.

However, since the flow rate of the refrigerant flowing to the indoor heat exchanger is fixed to the defrosting operation method, when the outdoor heat exchanger performing the defrosting operation is not smoothly defrosted, there is no way to solve this problem.

The present invention is to solve the above-mentioned problems, an air conditioner and a defrosting operation method of the air conditioner that can increase the amount of refrigerant flowing from the compressor to the hot gas pipe by adjusting the opening degree of the indoor expansion valve In providing.

In another aspect, the present invention provides an air conditioner and a defrosting operation method of the air conditioner that can provide a minimum heating to the user by controlling the opening degree of the indoor expansion valve within a minimum opening degree or a set time.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are 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 defrosting operation step of flowing a portion of the refrigerant compressed in the compressor to the outdoor heat exchanger by opening the defrost valve when the defrosting condition, the defrosting The first temperature judging step of determining whether the temperature of the outdoor heat exchanger reaches the defrost escape temperature after the start of the operation step and if the temperature of the outdoor heat exchanger does not reach the defrost exit temperature, opens the opening degree of the indoor expansion valve of the indoor heat exchanger. And a valve control step of closing at the first preset ratio.

The method may further include a minimum opening determining step of determining whether the opening degree of the expansion valve closed at the first predetermined ratio reaches a minimum opening degree.

Here, when the opening degree of the expansion valve closed at the first set ratio reaches a minimum opening degree, the second temperature judging step of determining whether the temperature of the outdoor heat exchanger corresponds to the defrost escape temperature and the temperature of the outdoor heat exchanger If the escape temperature does not reach the defrosting operation for closing the defrost valve may further include a step.

On the other hand, if the opening degree of the expansion valve closed at the first set ratio does not reach the minimum opening degree, the first temperature determination step may be performed. Here, the valve control step having passed the minimum opening degree determination step may close the opening degree of the indoor expansion valve at a second set ratio.

In order to achieve the above object, the air conditioner according to an embodiment of the present invention is a compressor for compressing the refrigerant, a hot gas pipe through which a portion of the refrigerant compressed by the compressor flows, the rest of the refrigerant compressed in the compressor flows An indoor heat exchanger, an indoor expansion valve in which the refrigerant heat-exchanged in the indoor heat exchanger is expanded, and some of the refrigerants that have passed through the hot gas pipe are heated while the refrigerant expanded in the indoor expansion valve flows. It includes a plurality of outdoor heat exchanger in which defrosting operation is performed while flowing, and the indoor expansion valve is variable in accordance with the refrigerant temperature of the outdoor heat exchanger performing the defrosting operation.

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

According to the air conditioner and the defrosting operation method of the air conditioner of the present invention has one or more of the following effects.

First, it is possible to vary the amount of refrigerant flowing to the outdoor heat exchanger during the defrosting operation by reducing the opening degree of the indoor expansion valve. Therefore, the defrosting operation efficiency of the outdoor heat exchanger can be increased.

Second, it is possible to reduce the opening degree of the variable indoor expansion valve to only the minimum opening degree to increase the defrosting operation efficiency and to continuously supply the minimum heating to the room.

Third, by setting the maximum set time that the defrosting operation method for controlling the opening degree of the indoor expansion valve can be performed, it is possible to supply normal heating to the room after a predetermined time.

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 during heating of the air conditioner according to the first embodiment of the present invention, Figure 2 is a block diagram showing a refrigerant flow during the defrost operation of the first outdoor heat exchanger of the first embodiment, 3 is a block diagram showing a refrigerant flow during the defrosting operation of the second outdoor heat exchanger of the first embodiment. 1 to 3, the overall configuration of the air conditioner of this embodiment will be described.

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 indoor expansion valve, an outdoor expansion mechanism, and a plurality of outdoor heat exchangers.

Compressors 11 and 13 compress the refrigerant. The compressors 11 and 13 may be any one of 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 this embodiment, it is determined whether the defrosting operation should be performed by measuring the pressure of the refrigerant on the refrigerant inlet side of the compressor. Therefore, the gas-liquid separator 14 of this embodiment is provided with a pressure sensor 15 for measuring the pressure of the refrigerant on the suction side of the compressors 11 and 13. On the other hand, the pressure sensor 15 may be installed between the gas-liquid separator 14 and the compressors (13, 15).

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, two connection pipes 23 and 25, and two defrost valves 27 and 29 installed in each connection pipe.

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 90 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 connecting pipes (23, 25) to be described later. Therefore, the refrigerant passing through the main pipe 21 flows into the connection pipes 23 and 25.

The connection pipes 23 and 25 include a first connection pipe 23 communicating with the first outdoor heat exchanger 80 and a second connection pipe 25 communicating with the second outdoor heat exchanger 70. Therefore, the refrigerant passing through each of the connection pipes 23 and 25 flows to each of the outdoor heat exchangers 70 and 80. The number of connection pipes 23 and 25 may correspond to the number of outdoor heat exchangers 70 and 80.

The defrost valves 27 and 29 include a first defrost valve 27 installed in the first connection pipe 23 and a second defrost valve 29 installed in the second connection pipe 25. Each defrost valve 27 and 29 opens and closes the connecting pipes 23 and 25. Specifically, during the heating operation, the defrost valves 27 and 29 are closed to prevent the refrigerant flowing through the connection pipes 23 and 25 from flowing to the outdoor heat exchangers 70 and 80. In the defrosting operation of the first outdoor heat exchanger 80, the first defrost valve 27 is opened to flow the refrigerant flowing through the first connection pipe 23 to the first outdoor heat exchanger 80. In the defrosting operation of the second outdoor heat exchanger 70, the second defrost valve 29 is opened to flow the refrigerant flowing through the second connection pipe 25 to the second outdoor heat exchanger 70.

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 90. 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 to the heat exchanger (90).

The indoor heat exchanger (90) cools or heats the indoor air by heat exchange between the refrigerant and the 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. In the present embodiment, a plurality of indoor heat exchangers may be provided to cool and heat a plurality of indoor spaces.

By adjusting the opening degree, the indoor expansion valve 92 expands the refrigerant flowing into the indoor heat exchanger 90 or expands the refrigerant flowing out of the indoor heat exchanger 90. In addition, by adjusting the opening degree, it is possible to adjust the amount of the refrigerant flowing out or in the indoor heat exchanger (90).

The outdoor expansion mechanisms 40 and 50 include outdoor 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 the indoor expansion valve 92.

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 coolant is prevented from flowing into 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, the outdoor heat exchangers 70 and 80 are defrosted 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 flowing through the compressors 11 and 13, the main pipe 21, and the first connection 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.

Meanwhile, a first temperature sensor 80a is installed in the first outdoor heat exchanger 80, and a second temperature sensor 70a is installed in the second outdoor heat exchanger 70, respectively. Each temperature sensor 70a or 80a measures the temperature of the refrigerant flowing out of each outdoor heat exchanger 70 or 80. The outdoor heat exchangers 70 and 80 are provided with a third temperature sensor 100 to measure the temperature of the refrigerant flowing into each outdoor heat exchanger 70 and 80 or the temperature of the outdoor air. And the third temperature sensor 100 may measure the temperature of the outdoor air passed through the outdoor heat exchanger (70, 80) to determine whether the defrost.

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.

Figure 4 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 4 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 expands in the indoor expansion mechanism (92). Becomes And it is evaporated while passing through the indoor heat exchanger (90). At this time, the indoor air whose temperature rises by heat exchange with the refrigerant while passing through the indoor heat exchanger 90 cools 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 90 and condenses while exchanging heat with the indoor air.

The refrigerant passing through the indoor heat exchanger (90) passes through the indoor expansion mechanism (92), 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 with outdoor air. The refrigerant passing through the second expansion valve 51 is introduced into the second outdoor heat exchanger 70 to evaporate while exchanging heat with the outdoor air. 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 flows 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. At this time, the amount of refrigerant flowing into the four-way valve 30 can be increased or decreased by appropriately adjusting the opening degree of the indoor expansion valve 92 as described later. As a result, the amount of refrigerant flowing into the hot gas pipe 20 may be adjusted by adjusting the opening degree of the indoor expansion valve 92.

The refrigerant flowing into the hot gas pipe 20 passes through the main pipe 21, the first connection pipe 23, and the first defrost valve 27, and enters the first outdoor heat exchanger 80 to exchange the first outdoor heat exchange. The frost formed on the machine 80 is removed. 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 (90). After passing through the indoor expansion valve 92 and expanding through the second expansion valve 51, the expansion is evaporated in the second outdoor heat exchanger 70, and passes through the four-way valve 30 to the compressor 11. As it flows into 13), it maintains heating cycle.

3 is a block diagram showing the flow of the refrigerant when the second outdoor heat exchanger 70 performs the defrosting operation. Referring to FIG. 3, 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.

5 is a flowchart showing a defrosting operation method of the air conditioner of the present embodiment. A defrosting operation method of the air conditioner of this embodiment will be described with reference to FIG.

In the defrosting operation S1, when the air conditioner corresponds to the defrosting condition, the first defrost valve 27 or the second defrost valve 29 is opened to exchange a part of the refrigerant compressed by the compressors 11 and 13 in the first outdoor heat exchange. Group 80 or the second outdoor heat exchanger (70).

The first temperature determination step S2 determines whether the temperature of the outdoor heat exchangers 70 and 80 in the defrosting operation reaches the defrost escape temperature. When the outdoor heat exchangers 70 and 80 perform a defrosting operation, the refrigerant of the high temperature and high pressure compressed by the compressors 11 and 13 flows into the outdoor heat exchangers 70 and 80 and is implanted in the outdoor heat exchangers 70 and 80. Defrost will be removed. As a result, in the process of performing the defrosting operation, the temperature of the outdoor heat exchangers 70 and 80 gradually increases, and reaches a predetermined defrost escape temperature.

However, since the flow rate distribution of the refrigerant compressed by the compressors 11 and 13 to the outdoor heat exchangers 70 and 80 performing the defrosting operation is not smooth, the defrosting operation is not substantially performed. It may happen that the temperature of stagnation does not increase by the defrost exit temperature.

Therefore, the first temperature determination step S2 monitors the temperatures of the outdoor heat exchangers 70 and 80 during defrost operation through the first temperature sensor 80a and the second temperature sensor 70a. The controller 200 determines whether the monitored temperature reaches a predetermined defrost exit temperature.

On the other hand, after the defrosting operation of the outdoor heat exchangers 70 and 80 is started, the first temperature determination step S2 may be performed after a predetermined time for which sufficient defrosting operation is performed.

When the temperature measured by the first temperature sensor 80a or the second temperature sensor 70a corresponds to the defrost exit temperature in the first temperature determination step S2, the outdoor heat exchangers 70 and 80 in defrost operation are defrosted. It ends (S6). The entire outdoor heat exchangers 70 and 80 may perform a heating operation, or a defrosting operation of other outdoor heat exchangers 70 and 80 may be performed.

If the temperature measured by the first temperature sensor 80a or the second temperature sensor 70a does not correspond to the defrost exit temperature in the first temperature determination step S2, the valve control step S3 is performed.

In the valve control step S3, the opening degree of the indoor expansion valve 92 is closed at the first predetermined ratio. Therefore, the amount of refrigerant flowing to the four-way valve 30 and the indoor heat exchanger 90 of the refrigerant compressed by the compressors 11 and 13 is reduced. The amount of the refrigerant flowing into the hot gas pipe 20 among the refrigerants compressed by the compressors 11 and 13 is increased.

Eventually, when the valve control step (S3) is performed, the refrigerant of the high temperature and high pressure flows to the outdoor heat exchanger (70, 80) to perform the defrosting operation to be able to remove the frost formed more quickly.

On the other hand, when the opening degree of the indoor expansion valve 92 is reduced, the amount of the refrigerant flowing to the indoor heat exchanger 90 is reduced, so that sufficient heating may not be supplied to the room. Therefore, the present embodiment further includes a minimum opening decision step S4 of determining whether the opening degree of the indoor expansion valve 92 corresponds to a predetermined minimum opening degree. Therefore, the present invention does not close the opening degree of the indoor expansion valve 92 more than a certain degree even in the process of defrosting operation can be supplied to the room with minimal heating.

On the other hand, when the opening degree of the indoor expansion valve 92 closed at the first set ratio corresponds to the predetermined minimum opening degree, the second determining whether the temperature of the outdoor heat exchanger (70, 80) during the defrosting operation corresponds to the defrost escape temperature Temperature determination step (S5) is performed.

When the temperature of the outdoor heat exchangers 70 and 80 corresponds to the defrost escape temperature in the second temperature determination step S5, the defrosting operation of the corresponding outdoor heat exchangers 70 and 80 is terminated (S6). And if the temperature of the outdoor heat exchanger (70, 80) does not correspond to the defrost escape temperature in the second temperature determination step (S5) defrosting operation forced termination step of forcibly terminating the defrost operation of the outdoor heat exchanger (70, 80) (S7) is performed.

That is, in this embodiment, after repeating predetermined steps for efficient defrosting of the outdoor heat exchangers 70 and 80, if the indoor expansion valve 92 is closed to the minimum opening degree, but it is determined that defrosting is not completed, defrosting operation is forced. By ending, the air conditioner does not perform the defrosting operation only.

When the opening degree of the indoor expansion valve 92 closed at the first setting ratio does not correspond to the predetermined minimum opening degree, the first temperature determination step S2 is performed again. At this time, the opening degree of the indoor expansion valve 92 is closed at the first set ratio, thereby reducing the amount of refrigerant flowing to the indoor heat exchanger 90. The reduced amount of refrigerant flows to the outdoor heat exchangers 70 and 80 during the defrosting operation, and the defrosting efficiency increases as more refrigerant flows to the outdoor heat exchangers 70 and 80.

That is, in the first temperature judging step S2 after performing the minimum opening judging step S4, the outdoor heat exchangers 70 and 80 have increased in the amount of refrigerant flowing to the outdoor heat exchangers 70 and 80 during defrosting. Measure the temperature of to determine whether the defrost escape temperature has been reached.

Here, when the temperature of the outdoor heat exchangers 70 and 80 corresponds to the defrost escape temperature, the defrosting operation is terminated (S6).

However, when the temperature of the outdoor heat exchangers 70 and 80 does not correspond to the defrost exit temperature, a valve control step S3 for additionally controlling the opening degree of the indoor expansion valve 92 is performed. In the additional valve control step S3, as in the first valve control step S3, the opening degree of the valve may be closed at the first set ratio, and the opening degree of the valve may be closed at another second set ratio at the first set ratio. .

Then, after the valve control step S3 is repeatedly performed, the minimum opening degree determination step S4 of determining whether the indoor expansion valve 92 closed at the first set ratio or the second set ratio corresponds to the minimum opening degree is performed. The subsequent steps are as described above.

That is, in this embodiment, the opening degree of the indoor expansion valve 92 until the temperature of the outdoor heat exchangers 70 and 80 during defrosting reaches the defrost escape temperature under the condition that the indoor expansion valve 92 does not reach the minimum opening degree. Repeat the steps to decrease. And the rate of reducing the opening degree of the indoor expansion valve 92 may be equally reduced to the first set ratio, or may be differently reduced to reduce the opening degree. In other words, as the turn is repeated, the rate of opening reduction may increase or decrease.

6 is a control block diagram for defrosting operation of the air conditioner of this embodiment.

Referring to FIG. 6, the air conditioner of the present embodiment further includes a controller 200. The controller 200 continuously monitors and monitors the temperatures of the outdoor heat exchangers 70 and 80 at the first temperature sensor 80a and the second temperature sensor 70a according to the defrosting operation method of the air conditioner described above. It is determined whether the prepared temperature corresponds to the defrost escape temperature. The control unit controls the indoor expansion valve 92 so that the opening degree of the indoor expansion valve 92 is closed at the first set ratio or the second set ratio, and continuously the opening degree of the indoor expansion valve 92 corresponds to the minimum opening degree. Monitor.

Second embodiment

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

The defrosting operation step S11, the first temperature determination step S12, the valve control step S13 and the defrosting operation termination step S16 of this embodiment are the defrosting operation step S1 and the first temperature determination step of the first embodiment. (S2), the valve control step (S3) and the defrosting operation end step (S6).

In the present embodiment, after the valve control step (S13), the maximum set time determination step (S14) for determining whether the maximum set time has been reached is performed. The maximum set time may be set based on the start point of the defrosting operation of the entire outdoor heat exchanger (70, 80). And it can be set on the basis of the start time of the defrost operation of the outdoor heat exchanger (70, 80) performing the defrost operation. It may also be set based on the first temperature determination step (S12) or valve control step (S13).

The controller 200 may determine whether the maximum set time is reached based on the reference time points. If the maximum set time is not reached, the processes of the first temperature judging step S12, the valve control step S13 and the maximum set time judging step S14 are repeatedly performed.

At this time, in the valve control step S13, as in the first embodiment, the ratio of reducing the opening degree of the indoor expansion valve 92 may be equally closed at the first set ratio. The first setting ratio and the second setting ratio may be closed while increasing or decreasing step by step.

As a result, the indoor expansion valve 92 is closed in sequence until the maximum set time is reached. Of course, the defrosting operation is terminated when the temperature of the outdoor heat exchangers 70 and 80 reaches the defrost escape temperature in this process.

If it is determined that the maximum setting time corresponds to the defrosting operation is forcibly terminated (S15). That is, the indoor expansion valve 92 is closed at the first set ratio or the second set ratio only until the maximum set time is reached. Therefore, the amount of refrigerant flowing into the indoor heat exchanger 90 by closing the indoor expansion valve 92 is reduced, and the defrosting operation of flowing the reduced refrigerant to the outdoor heat exchangers 70 and 80 during defrosting operation is within the maximum set time range. Will be performed on

And since the other configurations and operations are the same as the first embodiment of the present invention, the same reference numerals are used and detailed description thereof will be omitted.

Third embodiment

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

Each step of the defrosting operation method of this embodiment is the same as the first embodiment except that the maximum set time determination step S27 is added. Hereinafter, descriptions will be omitted focusing on differences from the first embodiment.

In the first embodiment, when the opening degree of the indoor expansion valve 92 closed at the first set ratio in the minimum opening degree determining step S24 does not correspond to the predetermined minimum opening degree, the first temperature determining step S2 and the valve control step ( S3) and the minimum opening judgment step S4 are repeated. As a result, the opening degree of the indoor expansion valve 92 is reduced until the temperature of the outdoor heat exchangers 70 and 80 during the defrosting operation corresponds to the defrost escape temperature. Therefore, the amount of refrigerant flowing to the outdoor heat exchangers 70 and 80 is increased.

However, in the present exemplary embodiment, when the opening degree of the indoor expansion valve 92 closed at the first setting ratio or the second setting ratio in the minimum opening degree determining step S24 does not correspond to the predetermined minimum opening degree, the additional maximum setting time determination step ( S27) is performed. The maximum set time judging step S27 of this embodiment is the same as the maximum set time judging step S14 of the second embodiment.

That is, in the present embodiment, the steps of the first embodiment and the second embodiment are applied repeatedly, and the indoor expansion valve 92 is closed in the process of closing the opening degree of the indoor expansion valve 92 at the first set ratio or the second set ratio. ) Determines whether the minimum setting opening degree and the maximum setting time are reached. And if each condition is met, even if the outdoor heat exchanger (70, 80) is not completed defrosting is forced to terminate the defrosting operation (S28).

8 shows a flowchart in which the maximum set time determination step S27 is performed after the minimum opening degree determination step S24, the order of the above steps may be changed.

And since the other configurations and operations are the same as the first embodiment of the present invention, the same reference numerals are used and detailed description thereof will be omitted.

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 during heating of an air conditioner according to a first embodiment of the present invention;

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

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

4 is a block diagram showing a refrigerant flow when cooling the air conditioner of the first embodiment;

5 is a flowchart showing a defrosting operation method of the air conditioner of the first embodiment;

6 is a control block diagram during defrosting operation of the air conditioner of the first embodiment;

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

8 is a flowchart showing a defrosting operation method of the air conditioner of the third 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 90: indoor heat exchanger

92: indoor expansion valve 100: third temperature sensor

Claims (10)

A defrosting operation of opening a defrost valve to flow a portion of the refrigerant compressed by the compressor to an outdoor heat exchanger if the defrost condition is applicable; A first temperature determining step of determining whether a temperature of the outdoor heat exchanger reaches a defrost escape temperature after the defrosting operation starts; And A valve control step of closing the opening degree of the indoor expansion valve of the indoor heat exchanger at a first predetermined ratio when the temperature of the outdoor heat exchanger does not reach the defrost exit temperature; Defrosting operation method of the air conditioner comprising a. The method according to claim 1, The defrosting operation method of the air conditioner further comprises a minimum opening degree determining step of determining whether the opening degree of the indoor expansion valve closed at the first set ratio reaches the minimum opening degree. The method according to claim 2, A second temperature judging step of determining whether a temperature of the outdoor heat exchanger corresponds to the defrost exit temperature when the opening degree of the indoor expansion valve closed at the first set ratio reaches a minimum opening degree; And A defrosting operation terminating step of closing the defrost valve if the temperature of the outdoor heat exchanger does not reach the defrost exit temperature; Defrosting operation method of the air conditioner further comprising. The method according to claim 2, If the opening degree of the indoor expansion valve closed at the first set ratio does not reach the minimum opening degree, the defrosting operation method of the air conditioner to perform the first temperature determination step. The method according to claim 4, The valve control step that passed the minimum opening determination step, The defrosting operation method of the air conditioner which closes the opening degree of the said indoor expansion valve by a 2nd set ratio. The method according to claim 1, And a maximum set time determining step of determining whether the maximum set time has been reached after the valve control step. The method according to claim 6, The defrosting operation method of the air conditioner further comprises the step of defrosting operation for closing the defrost valve when the maximum set time. The method according to claim 6, If the maximum time is not reached, Defrosting operation method of the air conditioner for performing the first temperature determination step. The method according to claim 8, The valve control step that passed the maximum set time determination step, The defrosting operation method of the air conditioner which closes the opening degree of the said indoor expansion valve by a 2nd set ratio. A compressor for compressing the refrigerant; A hot gas pipe through which a portion of the refrigerant compressed by the compressor flows; An indoor heat exchanger through which the rest of the refrigerant compressed by the compressor flows; An indoor expansion valve in which the refrigerant flowing through the indoor heat exchanger is expanded; Some of the heating operation is performed while the refrigerant expanded in the indoor expansion valve flows, and the other includes a plurality of outdoor heat exchanger in which the defrosting operation is performed while the refrigerant passing through the hot gas pipe flows, The indoor expansion valve is an air conditioner in which the opening degree is variable according to the temperature of the outdoor heat exchanger performing the defrosting operation.

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