KR102365378B1 - Air conditioner and control method thereof - Google Patents

Abstract

In the method of controlling an air conditioner according to an embodiment of the present invention, when a heating operation is started and a first preset time elapses, the first compression ratio and the first high pressure of the refrigeration cycle and the first operation frequency of the compressor are adjusted. a reference value detection step of detecting; a storage step of storing the first compression ratio, the first high pressure, and the first operating frequency in a storage unit; a variation value sensing step of detecting a second compression ratio and a second high pressure of the refrigerating cycle and a second operating frequency of the compressor when the heating operation is started and a second set time longer than the first set time elapses; Defrost to determine whether partial implantation occurs by comparing whether the second compression ratio is lower than the first compression ratio, comparing whether the second high pressure is lower than the first high pressure, and comparing whether the second operating frequency is higher than the first operating frequency entry judgment step; and when it is determined that partial frosting has occurred, a defrosting operation step of controlling the flow switching valve to perform a defrosting operation.

Description

Air conditioner and its control method

The present invention relates to an air conditioner and a control method thereof, and more particularly, to an air conditioner capable of defrosting operation and a control method thereof.

In general, an air conditioner refers to a device for controlling an indoor temperature in order to create a comfortable indoor air environment.

Such an air conditioner includes an indoor unit installed indoors and an outdoor unit supplying a refrigerant to the indoor unit. In addition, one or more indoor units may be connected to the outdoor unit.

In addition, the air conditioner may be operated by cooling or heating operation by supplying a refrigerant to the indoor unit. Here, the cooling operation or the heating operation, which is an operation method of the air conditioner, is determined according to the flow of the circulating refrigerant. That is, the air conditioner may operate in the cooling operation or in the heating operation according to the flow of the refrigerant.

First, the flow of the refrigerant when the air conditioner operates in the cooling operation will be described. The refrigerant compressed by the compressor of the outdoor unit becomes medium temperature and high pressure liquid refrigerant through an outdoor heat exchanger functioning as a condenser. When the liquid refrigerant is supplied to the indoor unit, a vaporization phenomenon may occur as the refrigerant expands in the indoor heat exchanger functioning as an evaporator. The temperature of the ambient air of the indoor heat exchanger is lowered by the vaporization phenomenon. In addition, when the indoor unit fan rotates, ambient air of the heat exchanger of the indoor unit whose temperature is lowered is discharged into the room.

Next, when the air conditioner operates in the heating operation, the flow of the refrigerant is as follows. When the high-temperature and high-pressure gas refrigerant is supplied from the compressor of the outdoor unit to the indoor unit, the high-temperature and high-pressure gas refrigerant may be liquefied in the indoor heat exchanger functioning as a condenser. The energy released by the liquefaction phenomenon raises the temperature of the ambient air of the indoor heat exchanger. In addition, when the fan of the indoor unit is rotated, ambient air of the indoor heat exchanger having an increased temperature may be discharged into the room. The liquefied refrigerant may be vaporized by being introduced into an outdoor heat exchanger functioning as an evaporator after being expanded in the main expansion device.

Meanwhile, when the air conditioner performs a heating operation, if the temperature of the outdoor air is too low or the humidity is high, ice may form on the surface of the outdoor heat exchanger. The implanted ice may deteriorate the heat exchange performance of the outdoor heat exchanger.

In order to prevent this phenomenon, the air conditioner may perform a defrosting operation. The air conditioner may operate a reverse cycle corresponding to the cooling operation, thereby allowing the outdoor heat exchanger to function as a condenser, thereby performing a defrosting operation to remove frost formation.

However, since the conventional air conditioner determines the inrush condition of the defrosting operation only by the temperature of the flow path, there is a problem in that partial implantation cannot be detected. If the heating operation is continued without detecting partial implantation, the compressor may be overloaded and heating agent may be generated.

One problem to be solved by the present invention relates to an air conditioner capable of performing a defrosting operation by determining partial frost.

In the method of controlling an air conditioner according to an embodiment of the present invention, when a heating operation is started and a first preset time elapses, the first compression ratio and the first high pressure of the refrigeration cycle and the first operation frequency of the compressor are adjusted. a reference value detection step of detecting; a storage step of storing the first compression ratio, the first high pressure, and the first operating frequency in a storage unit; a variation value sensing step of detecting a second compression ratio and a second high pressure of the refrigerating cycle and a second operating frequency of the compressor when the heating operation is started and a second set time longer than the first set time elapses; Comparing whether the second compression ratio is lower than the first compression ratio, comparing whether the second high pressure is lower than the first high pressure, and comparing whether the second operating frequency is higher than the first operating frequency, whether partial conception occurs Defrost entry determination step to determine; and when it is determined that partial frosting has occurred, a defrosting operation step of controlling the flow switching valve to perform a defrosting operation.

The step of detecting the reference value may include: a measurement process of measuring the compression ratio and high pressure of the refrigeration cycle and the operating frequency of the compressor for a set measurement time from the time when the heating operation is started and the first set time has elapsed; and calculating the average value of the compression ratio, the high pressure, and the operating frequency measured during the set measurement time as the first compression ratio, the first high pressure, and the first operating frequency, respectively.

The defrost entry determination step may include: a first determination process of determining whether the second compression ratio satisfies a first condition of being equal to or less than a first set ratio with respect to the first compression ratio; a second determination process of determining whether the second high pressure satisfies a second condition of equal to or less than a second set ratio with respect to the first high pressure; and a third determination process of determining whether the second operating frequency is equal to or greater than a third set ratio with respect to the first operating frequency or satisfies a third condition equal to the maximum operating frequency of the compressor.

In the defrost entry determination step, when all of the first condition, the second condition, and the third condition are satisfied, it may be determined that partial implantation has occurred.

The first set ratio may be smaller than the second set ratio.

The variable value detection step and the defrost entry determination step are carried out for a set determination time from the time when the second set time has elapsed, and the defrost entry determination step continuously includes the first condition, the first condition for the set determination time. When both condition 2 and condition 3 are satisfied, it can be determined that partial implantation has occurred.

The step of detecting the reference value includes calculating the first compression ratio and the first high pressure based on the temperatures respectively measured by the high-side temperature sensor and the low-side temperature sensor, and the detecting of the fluctuation value includes the high-side temperature The method may include calculating the second compression ratio and the second high pressure based on the temperatures respectively measured by the sensor and the low pressure side temperature sensor.

An air conditioner according to an embodiment of the present invention includes: a compressor whose operating frequency is controlled; a flow switching valve connected to the compressor through a discharge passage; an indoor heat exchanger connected to the flow switching valve and condensing the refrigerant compressed in the compressor during a heating operation; an expansion mechanism for decompressing the refrigerant condensed in the indoor heat exchanger; an outdoor heat exchanger evaporating the refrigerant depressurized in the expansion mechanism; a high-pressure side temperature sensor for sensing the temperature of the refrigerant discharged from the compressor; a low-pressure side temperature sensor for measuring the temperature of the outdoor heat exchanger; and detecting the compression ratio and high pressure of the refrigeration cycle based on the temperatures respectively measured by the high-pressure side temperature sensor and the low-pressure side temperature sensor, and detects the operating frequency of the compressor, and based on the sensed compression ratio, high pressure, and operating frequency A control unit may be included to determine whether partial implantation has occurred, and control to start a defrosting operation when it is determined that partial implantation has occurred.

The high-pressure side temperature sensor may be disposed in the indoor heat exchanger, and the low-pressure side temperature sensor may be disposed in the outdoor heat exchanger, and may be disposed closer to an outlet portion than an inlet portion of the outdoor heat exchanger.

The air conditioner according to an embodiment of the present invention may further include a storage unit for storing the compression ratio, high pressure, and operating frequency sensed by the control unit.

When the heating operation is started and a first set time elapses, the control unit detects a first compression ratio and a first high pressure of the refrigeration cycle, and a first operating frequency of the compressor, and the first compression ratio, the first high pressure and The first operating frequency is stored in the storage unit, and when a second set time longer than the first set time has elapsed after the heating operation is started and the second set time has elapsed, the second compression ratio and the second high pressure of the refrigeration cycle, and the second of the compressor Detects an operating frequency, compares whether the second compression ratio is lower than the first compression ratio, compares whether the second high pressure is lower than the first high pressure, and compares whether the second operating frequency is higher than the first operating frequency Thus, it can be determined whether partial implantation has occurred.

The control unit measures the compression ratio and high pressure of the refrigeration cycle and the operating frequency of the compressor for a set measurement time from the time when the heating operation is started and the first set time has elapsed, and the compression ratio measured during the set measuring time; Each average value of the high pressure and the operating frequency may be calculated as the first compression ratio, the first high pressure, and the first operating frequency, respectively.

The control unit, wherein the second compression ratio is less than or equal to a first set ratio with respect to the first compression ratio, the second high pressure is less than or equal to a second set ratio with respect to the first high pressure, and the second operation frequency is the first operation When the frequency is equal to or greater than the third set ratio or the maximum operating frequency of the compressor, it can be determined that partial implantation has occurred.

According to a preferred embodiment of the present invention, the defrosting operation can be started by determining whether or not there is an idea based on the change rate of the compression ratio. As a result, even when partial implantation occurs, the control unit can detect the implantation and perform a defrosting operation, and there is an advantage in that the heating agent can be improved by preventing the accumulation of freezing.

1 is a block diagram illustrating a refrigeration cycle of an air conditioner according to an embodiment of the present invention.
2 is a diagram illustrating a flow of a refrigerant during a heating operation of the air conditioner according to an embodiment of the present invention.
3 is a diagram illustrating a flow of a refrigerant during a cooling operation or a defrosting operation of the air conditioner according to an embodiment of the present invention.
4 is a control block diagram of an air conditioner according to an embodiment of the present invention.
FIG. 5 is a graph showing changes in the high-pressure side temperature, the low-pressure side temperature, and the compression ratio when total implantation occurs in the outdoor heat exchanger.
6 is a graph showing changes in the high-pressure side temperature, the low-pressure side temperature, and the compression ratio when partial implantation occurs in the outdoor heat exchanger.
7 and 8 are flowcharts illustrating an embodiment of a method for controlling an air conditioner according to an embodiment of the present invention.

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

1 is a block diagram illustrating a refrigeration cycle of an air conditioner according to an embodiment of the present invention, and FIG. 2 is a diagram showing a flow of refrigerant during a heating operation of the air conditioner according to an embodiment of the present invention; 3 is a diagram illustrating a flow of refrigerant during a cooling operation or a defrosting operation of the air conditioner according to an embodiment of the present invention, and FIG. 4 is a control block diagram of the air conditioner according to an embodiment of the present invention.

The air conditioner 1 according to the embodiment of the present invention includes a compressor 10 , an outdoor heat exchanger 20 , an expansion mechanism 30 , an indoor heat exchanger 40 , and a flow switching valve 50 . may include The air conditioner 1 may further include a gas-liquid separator 60 .

The compressor 10 may compress and discharge the refrigerant. The operating frequency of the compressor 10 may be adjusted. That is, the compressor 10 may be an inverter compressor rather than a constant speed compressor.

A discharge passage 11 and a suction passage 12 may be connected to the compressor 10 , and the refrigerant sucked into the compressor 10 through the suction passage 12 is compressed in the compressor 10 to the discharge passage 11 . can be ejected.

The flow switching valve 50 may be connected to the compressor 10 and the discharge passage 11 and the suction passage 12 . The flow switching valve 50 may include a four-way valve.

The flow switching valve 50 may communicate the discharge passage 11 and the indoor heat exchanger 40 during a heating operation, and may communicate the suction passage 12 and the outdoor heat exchanger 20 in communication. On the other hand, the flow switching valve 50 may communicate the discharge passage 11 and the outdoor heat exchanger 20 and the suction passage 12 and the indoor heat exchanger 40 during a cooling operation or a defrosting operation.

The outdoor heat exchanger 20 may exchange heat with the outside air and the refrigerant, and the refrigerant may be condensed during the cooling operation, and the refrigerant may be evaporated during the heating operation.

During the heating operation, the refrigerant is evaporated, and the temperature of the outdoor heat exchanger 20 may decrease, which may cause implantation on the surface of the outdoor heat exchanger 20 .

In general, implantation occurs when the temperature of the outside air is very low (eg, 1 ℃ or less), but even when the temperature of the external air is somewhat high (eg, 5 to 10 ℃), implantation may occur if the humidity is high. In particular, partial implantation may occur when implantation progresses slowly due to a change in humidity. When an implantation occurs, the air conditioner 1 may perform a defrosting operation. During the defrosting operation, the high-temperature and high-pressure refrigerant condensed in the compressor may flow into the outdoor heat exchanger 20 to melt the frost. A control method for starting a defrosting operation by detecting a partial frost will be described in detail later.

The indoor heat exchanger 40 may exchange heat between the air in the indoor space and the refrigerant, the refrigerant may be evaporated during the cooling operation, and the refrigerant may be condensed during the heating operation.

The expansion mechanism 30 may be installed in a flow path connecting the outdoor heat exchanger 20 and the indoor heat exchanger 40 . For example, the expansion mechanism 30 may include an electronic expansion valve capable of adjusting the opening degree.

The gas-liquid separator 60 may be installed in the suction passage 12 , and may perform a function of separating gas-phase refrigerant from the evaporated refrigerant and supplying it to the compressor 10 .

The air conditioner 1 may further include an outdoor fan 21 installed on one side of the outdoor heat exchanger 20 to provide blowing force so that outdoor air flows toward the outdoor heat exchanger 20 . The outdoor fan 21 may be coupled to a fan motor 21A controlled to enable forward or reverse rotation of the outdoor fan 21 .

The outdoor heat exchanger 20 , the outdoor fan 21 , and the fan motor 21A may be installed inside the outdoor unit case O . For convenience of explanation, in FIGS. 1 to 3 , only the outdoor heat exchanger 20 , the outdoor fan 21 and the fan motor 21A are installed inside the outdoor unit case O, but the compressor 10 ), the gas-liquid separator 60 , the flow switching valve 50 and the expansion mechanism 30 may also be installed inside the outdoor unit case O.

When the outdoor fan 21 rotates forward, the outdoor air flows into the outdoor unit case O and exchanges heat with the outdoor heat exchanger 20, and the heat-exchanged outdoor air may be discharged to the outside of the outdoor unit case O. On the other hand, when the outdoor fan 21 rotates in reverse, the internal air of the outdoor unit case O flows toward the outdoor heat exchanger 20 to exchange heat, and the heat-exchanged internal air is discharged to the outside of the outdoor unit case O. can be

The air conditioner 1 may further include an indoor fan 41 installed on one side of the indoor heat exchanger 40 to flow air in the indoor space toward the indoor heat exchanger 40 . A fan motor 41A may be coupled to the indoor fan 41 .

Hereinafter, the flow of the refrigerant will be described.

When the air conditioner 1 is in the cooling or defrosting operation, the refrigerant compressed in the compressor 10 flows into the outdoor heat exchanger 20 via the flow switching valve 50, and in the outdoor heat exchanger 20 The condensed refrigerant is decompressed by the expansion mechanism 30 and flows into the indoor heat exchanger 40 . The refrigerant evaporated in the indoor heat exchanger 40 flows into the gas-liquid separator 60 through the flow switching valve 50 . Then, the gas-phase refrigerant separated in the gas-liquid separator 60 is sucked back into the compressor 100 .

On the other hand, when the air conditioner 1 performs a heating operation, the refrigerant compressed in the compressor 10 flows into the indoor heat exchanger 40 via the flow switching valve 50 , and is condensed in the indoor heat exchanger 40 . The refrigerant is decompressed in the expansion mechanism 30 and flows into the outdoor heat exchanger 20 . The refrigerant evaporated in the outdoor heat exchanger 20 flows into the gas-liquid separator 60 through the flow switching valve 50 . Then, the gas-phase refrigerant separated in the gas-liquid separator 60 is sucked back into the compressor 100 .

Meanwhile, the air conditioner 1 may further include a high-pressure side temperature sensor 71 , a low-pressure side temperature sensor 72 , and an outdoor temperature sensor 73 .

The high-pressure side temperature sensor 71 may detect the temperature of the refrigerant discharged from the compressor 10 during heating operation. The high-pressure side temperature sensor 71 may be disposed in the indoor heat exchanger 40 . In addition, the high-pressure side temperature sensor 71 may be disposed in the flow path connecting the flow switching valve 50 and the indoor heat exchanger 40 , or may be disposed in the discharge flow path 11 .

The low-pressure side temperature sensor 72 may be disposed in the outdoor heat exchanger 20 to measure the temperature of the outdoor heat exchanger 20 . The low-pressure side temperature sensor may be disposed closer to the outlet than the inlet of the outdoor heat exchanger 20 based on the flow of refrigerant during the heating operation.

In general, when an implantation occurs in the outdoor heat exchanger 20, since the temperature of the outdoor heat exchanger 20 is lowered, the temperature measured by the low-pressure side temperature sensor 71 may be lowered, thereby determining that an implantation has occurred. .

However, depending on the attachment position of the outdoor heat exchanger 20 of the low pressure side temperature sensor 72 , even if an implantation occurs, the low pressure side temperature sensor 72 may not detect a decrease in temperature. This can be particularly problematic for partial rather than total implantation. For example, when partial implantation occurs in a part of the upper side of the outdoor heat exchanger 20 but the low pressure side temperature sensor is disposed below the outdoor heat exchanger 20, the temperature measured by the low pressure side temperature sensor 72 decreases may not go Accordingly, since the air conditioner 1 does not detect an implantation, it does not enter the defrosting operation and maintains the heating operation, thereby causing accumulated icing, and there is a fear that a heating effect may occur. To avoid such concerns, a process capable of detecting partial implantation is required, which will be described in detail later.

The outdoor temperature sensor 73 may be provided in the outdoor unit case O to measure the temperature of the outdoor air.

Meanwhile, the air conditioner 1 may further include a controller 90 .

The control unit 90 may receive temperature values measured by the high-pressure side temperature sensor 71 , the low-pressure side temperature sensor 72 , and the outdoor temperature sensor 73 , respectively.

The control unit 90 can calculate the high pressure of the refrigeration cycle based on the temperature value measured by the high-pressure side temperature sensor 71, and based on the temperature value measured by the low-pressure side temperature sensor 72, the temperature value of the refrigeration cycle. Low pressure can be calculated. Each of the calculations may be made according to a temperature-pressure table or a calculation formula stored in the control unit 90 . For example, the high pressure of the refrigeration cycle may be proportional to the temperature value measured by the high-pressure side temperature sensor 71 , and the low pressure may be proportional to the temperature value measured by the low-pressure side temperature sensor 72 .

Accordingly, the control unit 90 may calculate the compression ratio of the refrigeration cycle, which is the ratio of the high pressure and the low pressure.

In addition, the controller 90 may control the on-off and operating frequency of the compressor 10 . At the same time, the controller 90 may sense the operating frequency of the compressor 10 .

In addition, the control unit 90 may adjust the flow switching valve 50 according to the operation mode of the air conditioner 1 , may adjust the opening degree of the expansion mechanism 30 , and may include an outdoor fan 21 and an indoor fan ( 41) can control the operating frequency and rotation direction.

Meanwhile, the air conditioner 1 may further include a storage unit 80 . The storage unit 80 may store the compression ratio, high pressure, and operating frequency sensed by the control unit 90 . Also, the control unit 90 may call the compression ratio, high pressure, and operating frequency stored in the storage unit 80 .

5 is a graph showing changes in the high-pressure side temperature, the low-pressure side temperature, and the compression ratio when total implantation occurs in the outdoor heat exchanger, and FIG. 6 is the high-pressure side temperature and the low pressure side temperature when partial implantation occurs in the outdoor heat exchanger and the change of the compression ratio are graphs.

The numerical values displayed on the right side of the graphs shown in FIGS. 5 and 6 correspond to the temperature (a) measured by the high-pressure side temperature sensor 71 and the temperature (b) measured by the low-pressure side temperature sensor 72, and the graph The numerical value displayed on the left side of , corresponds to the compression ratio c calculated by the controller 90 based on the temperature measured by each of the temperature sensors 71 and 72 .

The total implantation measurement was carried out under the conditions of an indoor temperature of 20 °C, an outdoor temperature of 1 °C, and a humidity of 100%, and the partial implantation measurement was carried out under the conditions of an indoor temperature of 25 °C, an outdoor temperature of 5 to 10 °C, and a humidity of 50 to 60%.

When total implantation occurs in the outdoor heat exchanger 20 during heating operation, the temperature value measured by the low-pressure side temperature sensor 72 disposed in the outdoor heat exchanger 20 may decrease due to freezing. In addition, since the heat exchange efficiency of the refrigeration cycle is reduced due to the conception, the temperature measured by the high-pressure side temperature sensor 71 may also decrease. However, since the low pressure of the refrigerating cycle falls more than the high pressure of the refrigerating cycle, the compression ratio of the refrigerating cycle may increase, and the operating frequency of the compressor 10 may be maintained.

On the other hand, when partial implantation occurred in the outdoor heat exchanger 20 during heating operation and the low-pressure side temperature sensor 72 is disposed in a portion where no implantation occurred in the outdoor heat exchanger 20, the low-pressure side temperature sensor 72 The measured temperature value may be maintained without detecting the implantation. However, since the implantation has actually occurred, the heat exchange efficiency of the refrigeration cycle is reduced, so that the temperature measured by the high-pressure side temperature sensor 71 may drop. For this reason, the control unit 90 detects that the high pressure decreases while the low pressure is maintained, and the compression ratio calculated by the control unit 90 may decrease. Accordingly, the controller 90 may increase the operating frequency of the compressor 10 to compensate for the lowered compression ratio.

7 and 8 are flowcharts illustrating an embodiment of a method for controlling an air conditioner according to an embodiment of the present invention.

Hereinafter, a method for controlling the air conditioner according to the present embodiment will be described.

The control method according to the present embodiment detects partial implantation when partial implantation has occurred in the outdoor heat exchanger 20 and the low-pressure side temperature sensor 72 is disposed in a portion of the outdoor heat exchanger 20 where implantation does not occur. This is a control for defrosting.

The control method according to this embodiment includes a reference value detection step (S13), a storage step (S14), a change value detection step (S17), a defrost entry determination step (S20), and a defrost execution step (S25). can do. Hereinafter, it will be described in more detail.

When the heating operation is started (S11), evaporation of the refrigerant occurs in the outdoor heat exchanger 20, and the temperature of the outdoor heat exchanger 20 may drop, and when the heating operation continues for a long time, the conception of the outdoor heat exchanger 20 may occur. can occur

The control unit 90 may determine whether the heating operation is started and a preset first set time t1 has elapsed (S12).

It is preferable that the first set time t1 is short enough that the implantation does not occur or occurs weakly. For example, the first set time t1 may be 15 minutes.

When the heating operation is started and the first set time t1 has elapsed, the reference value detection step may be performed. In the reference value detection step, the control unit 90 may detect the first compression ratio r1 and the first high pressure p1 of the refrigeration cycle, and the first operating frequency f1 of the compressor 10 (S13).

The reference value detection step S13 may include a measurement process and an average value calculation process.

During the measurement process, the control unit 90 controls the compression ratio and high pressure of the refrigeration cycle and the operating frequency of the compressor 10 for the set measurement time t3 from the time when the heating operation is started and the first set time t1 has elapsed. can be measured multiple times. For example, the set measurement time t3 may be 6 minutes.

The control unit 90 may measure the compression ratio, high pressure, and operating frequency at predetermined time intervals, but is not limited thereto.

When the average value measurement process is carried out after the set measurement time t3 has elapsed, the control unit 90 may calculate an average value of each of the compression ratio, the high pressure and the operating frequency measured during the set measurement time t3 . In addition, each of the average values may be calculated as the first compression ratio r1 , the first high pressure p1 , and the first operating frequency f1 .

That is, the first compression ratio r1 is the average value of the pressure ratio sensed during the set measurement time t3, the first high pressure p1 is the average value of the high pressure sensed during the set measurement time t3, and the first operating frequency f1 ) may be an average value of the detected operating frequencies during the set measurement time t3.

A storage step may be performed after the reference value detection step. In the storage step, the controller 90 may store the calculated first compression ratio r1, the first high pressure p1, and the first operating frequency f1 in the storage unit 80 (S14). The first compression ratio r1 , the first high pressure p1 , and the first operating frequency f1 stored in the storage unit 80 may be reference values for determining whether an implantation occurs.

The control unit 90 may determine whether the heating operation is started and a second preset time t2 has elapsed (S15).

The second set time t2 may be longer than the first set time t1. It is preferable that the second set time t2 is a time long enough to be concerned about the occurrence of an idea. For example, the second set time t2 may be 40 minutes.

When the heating operation is started and the second set time elapses, the control unit 90 may turn on the timer t (S16). After the timer t is turned on, a change value detection step may be performed.

During the detection of the fluctuation value, the control unit 90 may detect the second compression ratio r2 and the second high pressure p2 of the refrigeration cycle, and the second operation frequency f2 of the compressor 10 (S17). The second compression ratio r2, the second high pressure p2, and the second operating frequency f2 may be comparison values for determining whether an implantation occurs.

After the change value detection step, a defrost entry determination step may be performed. The defrost entry determination step may be a step of determining whether to perform a defrost operation by determining whether partial defrost has occurred.

As described above, when partial implantation occurs, the compression ratio and high pressure of the refrigeration cycle sensed by the control unit may decrease, and the operating frequency of the compressor 10 may increase.

Therefore, at the time of the defrost entry determination step (S20), the control unit 90 compares whether the second compression ratio r2 is lower than the first compression ratio r2, and the second high pressure p2 is lower than the first high pressure p1. It is possible to determine whether or not a partial conception occurs by comparing whether or not the second operating frequency f2 is higher than the first operating frequency f1. In this case, the first compression ratio r1, the first high pressure p1, and the first operating frequency f1 may be values stored in the storage unit 80 during the storage step, respectively.

In more detail, the defrost entry determination step (S20) includes a first determination process of determining whether the second compression ratio r2 satisfies the first condition that is less than or equal to the first set ratio m1 with respect to the first compression ratio r1; A second determination process of determining whether the second high pressure p2 satisfies the second condition of being equal to or less than the second set ratio m2 with respect to the first high pressure p1, and the second operating frequency f2 is the first operating frequency f1 ) may include a third determination process of determining whether the third set ratio (m3) or more or the third condition (S23) equal to the maximum operating frequency of the compressor 10 is satisfied.

During the first determination process, the control unit 90 may determine whether a first condition is satisfied, and the first condition is that the second compression ratio r2 is a first set ratio m1 with respect to the first compression ratio r1. It can be satisfied when The first set ratio m1 may be less than 1 (S21).

For example, the first set ratio m1 may be 0.9. In this case, the first condition may be satisfied when the second compression ratio r2 is 10% or more lower than the first compression ratio r1.

During the second determination process, the control unit 90 may determine whether a second condition is satisfied, and the second condition is that the second high pressure p2 is a second set ratio m2 to the first high pressure p1. It can be satisfied when the following is (S22). The second preset ratio m1 may be less than 1, and may be greater than the first preset ratio m1.

For example, the second set ratio m2 may be 0.95. In this case, the second condition may be satisfied when the second high pressure p2 is 5% or more lower than the first high pressure p1.

During the third determination process, the control unit 90 may determine whether a third condition is satisfied, and the third condition is that the second operating frequency f2 is a third setting ratio ( m3) or more or it can be satisfied when it is equal to the maximum operating frequency of the compressor (10). The third set ratio m1 may be greater than 1.

For example, the third set ratio m3 may be 1.1. In this case, the third condition can be satisfied only when the second operating frequency f2 is higher than the first operating frequency f1 by 10% or more or is equal to the maximum operating frequency of the compressor 10 .

For convenience of explanation, although it is illustrated in FIG. 8 that the determination of the first condition, the second condition, and the third condition is sequentially performed, the present invention is not limited thereto. For example, the control unit may determine in the order of the second condition, the third condition, and the first condition.

Meanwhile, when all of the first condition, the second condition, and the third condition are satisfied, the control unit 90 may determine whether the timer t is equal to or longer than the set determination time t4 ( S24 ).

If the timer is less than the set determination time, the control unit may proceed to the change value detection step (S17) and the defrost entry determination step (S20) again (B).

This means that the second compression ratio r2, the second high pressure p2, and the second operation frequency f2 are continuously updated until the timer t reaches the set determination time t4, and the updated values are This means that it is repeatedly judged whether the first condition, the second condition, and the third condition are all satisfied.

If the first condition, the second condition and the third condition are not satisfied even once before the timer t reaches the set determination time t4, the control unit 90 resets the timer to turn it on again and changes The value detection step (S17) and the defrost entry determination step (S20) may be performed (A).

On the other hand, when the timer t is longer than the set determination time t4, the control unit 90 may start the defrosting operation (S25). That is, when the satisfaction of the first condition, the second condition, and the third condition is maintained during the set determination time t4, it is determined that partial implantation has occurred and the defrosting execution step may be performed.

For example, the set determination time t4 may be 3 minutes. In this case, the second compression ratio r2, the second high pressure p2, and the second operating frequency f2 measured at a predetermined time interval for 3 minutes are the first, second and third conditions The defrost operation can be started only when it is continuously satisfied for a minute.

However, it will be apparent to those skilled in the art that a control method for determining that partial defrost has occurred if the judgment conditions are not continuously satisfied during the set judgment time as in the present embodiment and the judgment conditions are satisfied at a certain point in time are also included in the scope of the present invention. will be. In this case, the process of turning on the timer t ( S16 ) and the process of determining whether the timer t is longer than the set determination time ( S24 ) may be omitted.

When the defrosting operation is started, the controller 90 may control the flow switching valve 50 to communicate the discharge flow path 11 of the compressor 10 with the outdoor heat exchanger 20 . Accordingly, the high-temperature and high-pressure refrigerant discharged from the compressor 10 flows to the outdoor heat exchanger 20 to perform defrosting. In addition, the controller 90 may reversely rotate the outdoor fan 21 to blow hot heat inside the outdoor unit case 120 to the outdoor heat exchanger 20 , so that defrosting can be performed quickly.

On the other hand, it is self-evident that the air conditioner according to an embodiment of the present invention can perform defrosting by sensing the entire defrost, in addition to the control method of performing the defrosting by detecting the partial defrost as described above.

Hereinafter, a method of detecting the entire defrost will be briefly described.

The air conditioner 1 according to an embodiment of the present invention may be capable of defrosting operation according to a minimum pipe temperature. In this case, when a relatively short predetermined time (for example, 10 minutes) has elapsed after the heating operation is started, and the measured value of the low pressure side temperature sensor 72 is very low compared to the outdoor temperature, the defrosting operation can be performed. there is.

In addition, the air conditioner 1 according to an embodiment of the present invention may be capable of defrosting operation according to the pipe temperature for each outdoor temperature. In this case, when a relatively long predetermined time (for example, 30 minutes) has elapsed after the heating operation is started, when the measured value of the low pressure side temperature sensor 72 is significantly lower than the measured value of the outdoor temperature sensor 73 , , defrost operation can be performed.

In addition, the air conditioner 1 according to an embodiment of the present invention may be capable of defrosting operation according to the rate of change of the pipe temperature. In this case, a fairly long predetermined time (for example, 40 minutes) has elapsed after the heating operation is started, and if the rate of change of the temperature measured by the low-pressure side temperature sensor 72 for a certain period of time is high (for example, 3 minutes) drop more than 5℃ during the period) and defrost operation can be performed.

In addition, the air conditioner 1 according to an embodiment of the present invention may be capable of defrosting operation according to the operating time of the heating operation. In this case, a very long predetermined time (for example, 120 minutes) has elapsed since the heating operation is started, and the temperature measured by the outdoor temperature sensor 73 is low (for example, -3°C or less), and the low pressure side If the temperature measured by the temperature sensor is lower than that (for example, -6℃ or less), the defrost operation can be performed.

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

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

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

1: air conditioner 10: compressor
11: discharge flow path 12: suction flow path
20: outdoor heat exchanger 21: outdoor fan
30: expansion mechanism 40: indoor heat exchanger
41: indoor fan 50: flow selector valve
60: gas-liquid separator 71: high-pressure side temperature sensor
72: low pressure side temperature sensor 73: outdoor temperature sensor
80: storage unit 90: control unit

Claims (13)

a reference value sensing step of detecting a first compression ratio and a first high pressure of the refrigerating cycle and a first operating frequency of the compressor when the heating operation is started and a first preset time has elapsed;
a storage step of storing the first compression ratio, the first high pressure, and the first operating frequency in a storage unit;
a variation value sensing step of detecting a second compression ratio and a second high pressure of the refrigerating cycle and a second operating frequency of the compressor when the heating operation is started and a second set time longer than the first set time elapses;
Comparing whether the second compression ratio is lower than the first compression ratio, comparing whether the second high pressure is lower than the first high pressure, and comparing whether the second operating frequency is higher than the first operating frequency, whether partial conception occurs Defrost entry determination step to determine; and
A control method of an air conditioner comprising: when it is determined that partial frost has occurred, a defrosting operation is performed by controlling a flow switching valve. The method of claim 1,
The reference value detection step is,
a measuring process of measuring the compression ratio and high pressure of the refrigeration cycle and the operating frequency of the compressor for a set measuring time from the time when the heating operation is started and the first set time has elapsed; and
and calculating an average value of each of the average values of the compression ratio, high pressure, and operating frequency measured during the set measurement time as the first compression ratio, the first high pressure, and the first operating frequency. The method of claim 1,
The defrost entry determination step is,
a first determination process of determining whether the second compression ratio satisfies a first condition of being equal to or less than a first set ratio with respect to the first compression ratio;
a second determination process of determining whether the second high pressure satisfies a second condition of equal to or less than a second set ratio with respect to the first high pressure; and
and a third determination process of determining whether the second operating frequency is equal to or greater than a third set ratio with respect to the first operating frequency or satisfies a third condition equal to the maximum operating frequency of the compressor. 4. The method of claim 3,
The defrost entry determination step is,
A control method of an air conditioner in which it is determined that partial implantation has occurred when the first, second, and third conditions are all satisfied. 4. The method of claim 3,
The first set ratio is less than the second set ratio control method of the air conditioner. 4. The method of claim 3,
The change value detection step and the defrost entry determination step are,
It is carried out during the set judgment time from the time when the second set time has elapsed,
The defrost entry determination step is,
A control method of an air conditioner for determining that partial conception has occurred when all of the first, second, and third conditions are continuously satisfied during the set determination time. The method of claim 1,
The reference value detection step is,
Calculating the first compression ratio and the first high pressure based on the temperatures respectively measured by the high-pressure side temperature sensor and the low-pressure side temperature sensor,
The change value detection step is,
and calculating the second compression ratio and the second high pressure based on the temperatures respectively measured by the high pressure side temperature sensor and the low pressure side temperature sensor. Compressor whose operating frequency is controlled;
a flow switching valve connected to the compressor through a discharge passage;
an indoor heat exchanger connected to the flow switching valve and condensing the refrigerant compressed in the compressor during a heating operation;
an expansion mechanism for decompressing the refrigerant condensed in the indoor heat exchanger;
an outdoor heat exchanger evaporating the refrigerant depressurized in the expansion mechanism;
a high-pressure side temperature sensor for sensing the temperature of the refrigerant discharged from the compressor;
a low-pressure side temperature sensor for measuring the temperature of the outdoor heat exchanger; and
Detects the compression ratio and high pressure of the refrigeration cycle based on the temperatures respectively measured by the high-pressure side temperature sensor and the low-pressure side temperature sensor, detects the operating frequency of the compressor, and partially based on the sensed compression ratio, high pressure, and operating frequency An air conditioner including a control unit to determine whether an implantation has occurred, and to control to start a defrosting operation when it is determined that a partial implantation has occurred. 9. The method of claim 8,
The high-pressure side temperature sensor is disposed in the indoor heat exchanger,
The low-pressure side temperature sensor is disposed in the outdoor heat exchanger, and is disposed closer to an outlet portion than an inlet portion of the outdoor heat exchanger. 9. The method of claim 8,
The air conditioner further comprising a storage unit for storing the compression ratio, high pressure, and operating frequency sensed by the control unit. 11. The method of claim 10,
The control unit is
When the heating operation is started and a first set time elapses, the first compression ratio and the first high pressure of the refrigeration cycle, and the first operation frequency of the compressor are sensed,
Storing the first compression ratio, the first high pressure, and the first operating frequency in the storage unit,
When the heating operation is started and a second set time longer than the first set time elapses, a second compression ratio and a second high pressure of the refrigerating cycle, and a second operating frequency of the compressor are sensed,
Comparing whether the second compression ratio is lower than the first compression ratio, comparing whether the second high pressure is lower than the first high pressure, and comparing whether the second operating frequency is higher than the first operating frequency, whether partial conception occurs The air conditioner to judge. 12. The method of claim 11,
The control unit is
Measuring the compression ratio and high pressure of the refrigerating cycle and the operating frequency of the compressor for a set measurement time from the time when the heating operation is started and the first set time has elapsed,
The air conditioner for calculating each average value of the compression ratio, high pressure, and operating frequency measured during the set measurement time as the first compression ratio, the first high pressure and the first operating frequency, respectively. 12. The method of claim 11,
The control unit is
The second compression ratio is less than or equal to a first set ratio with respect to the first compression ratio,
The second high pressure is less than or equal to a second set ratio with respect to the first high pressure,
When the second operating frequency is equal to or greater than a third set ratio with respect to the first operating frequency or is equal to the maximum operating frequency of the compressor, the air conditioner determines that partial implantation has occurred.

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