KR20080035878A - Air-conditioner and defrosting method of the same air-conditioner - Google Patents

Abstract

An air conditioner and a defrosting method thereof are provided to rotate an outdoor fan weakly for preventing the outdoor fan and a front grill from being frozen during defrosting operation, thereby keeping the heating performance of the air conditioner constantly. An air conditioner includes a first temperature sensor(10) sensing pipe temperature of an outdoor heat exchanger, and a second temperature sensor(20) for sensing atmospheric temperature. A controller(30) is input with the temperature values of the first and second temperature sensors and carries out defrosting operation if the outdoor heat exchanger satisfies defrosting conditions, wherein the controller rotates an outdoor fan(50) if the pipe temperature of the outdoor heat exchanger is equal to or higher than a third temperature.

Description

Air conditioner and defrosting method of the air conditioner {air-conditioner and defrosting method of the same air-conditioner}

1 is a block diagram of a defrosting operation control apparatus of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a graph illustrating a process of sequentially performing the defrosting method of the air conditioner illustrated in FIG. 1 according to time.

3 is a flow chart of a defrosting method of the air conditioner shown in FIG.

4 is a graph showing the pipe temperature of the indoor heat exchanger measured in a cold humid environment during the heating operation of the conventional air conditioner.

FIG. 5 is a graph illustrating a pipe temperature of an indoor heat exchanger measured in a cold and humid environment during a heating operation of the air conditioner illustrated in FIG. 1.

6 is a view showing the state of the outdoor unit fan and the front grill during the heating operation of the conventional air conditioner.

FIG. 7 is a diagram illustrating a state of an outdoor unit fan and a front panel grill during heating operation of the air conditioner illustrated in FIG. 1.

<Simple description of the code for the main part of the drawing>

10: first temperature sensor 20: second temperature sensor

30 control unit 40 compressor

50: outdoor unit fan 55: front grill

60: indoor unit fan 70: four-way valve

100: air conditioner

The present invention relates to an air conditioner and a defrosting method of the air conditioner, and more particularly, to an air conditioner capable of defrosting an outdoor unit fan during a defrosting operation and a defrosting method of the air conditioner.

In general, an air conditioner is a cooling device that discharges cold air generated by heat exchange with ambient air due to evaporation of a refrigerant to a room using an indoor unit fan by compressing, evaporating, and condensing a predetermined refrigerant. It has been used mainly.

Recently, however, by using the refrigerant compression, evaporation, and condensation cycles in reverse, hot air generated through heat exchange between refrigerant and ambient air due to refrigerant condensation is discharged to the room using an indoor unit fan, thereby providing both heating and cooling functions. Air conditioners are becoming widespread.

However, such a combined air-conditioning and air conditioner, when performing the heating operation, if the outdoor environment is below the freezing point temperature and there is a certain amount of moisture, the outdoor heat exchanger exposed to the outdoor environment is dewy, and progresses to freezing.

Therefore, when the air conditioner continues heating operation, as the heat exchange surface of the outdoor heat exchanger freezes, the temperature of the blown air through the indoor heat exchanger is lowered, thereby lowering the function of heating. Therefore, the defrosting operation needs to be performed at regular intervals in order to remove the freezing and to continue the heating operation even in the outdoor environment below the freezing point.

However, in the defrosting method of the conventional air conditioner as described above, freezing occurs in the outdoor unit fan and the front grill without considering the humidity at a temperature below zero in winter, thereby increasing the resistance of the outdoor unit fan, thereby increasing the outdoor unit. Even if the fan is operated at the same rotational speed, there is a problem that the amount of air is reduced to significantly reduce the heating performance.

It is an object of the present invention to provide an air conditioner capable of maintaining a heating performance of an air conditioner by defrosting an outdoor unit fan during a defrosting operation of an air conditioner and a defrosting method of the air conditioner.

The present invention provides an outdoor unit fan (50), an outdoor heat exchanger (not shown) disposed on an air intake side of the outdoor unit fan (50), and a pipe temperature (T1) of the outdoor heat exchanger (not shown). Input the first temperature sensor 10, the second temperature sensor 20 for sensing the outdoor temperature (T2), and the temperature values (T1, T2) detected by the first and second temperature sensors (10, 20) When the outdoor heat exchanger (not shown) satisfies the defrosting condition, the defrosting operation is performed. When the pipe temperature of the outdoor heat exchanger (not shown) is greater than or equal to the third temperature T3 during the defrosting operation, the outdoor unit fan 50 It provides an air conditioner including a control unit 30 for rotating.

In addition, according to another aspect of the present invention, the present invention includes an outdoor unit fan (50) and an outdoor heat exchanger (not shown) disposed on the air intake side of the outdoor unit fan (50), the defrosting operation within the heating operation period A defrosting method of an air conditioner performed, comprising: switching the air conditioner to a cooling operation mode to start a defrosting operation (S20); When the pipe temperature of the outdoor heat exchanger during the defrosting operation is greater than or equal to the third temperature T3 (S30), defrosting the outdoor unit fan by rotating the outdoor unit fan provides a defrosting method of the air conditioner including the step (S40). do.

In addition, the present invention provides a defrosting method of the air conditioner for rotating the outdoor unit fan for 30 seconds to 120 seconds at a rotation speed of 300 RPM to 750 RPM in the step (S40) of the outdoor unit fan 50 defrosting.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a defrosting operation control apparatus of an air conditioner according to an embodiment of the present invention.

Referring to Figure 1, the air conditioner 100 according to an embodiment of the present invention is formed of the same components as the prior art. That is, as shown in Figure 1, the first temperature sensor 10 for sensing the pipe temperature of the outdoor heat exchanger (not shown), the second temperature sensor 20 for sensing the outdoor temperature, and the first and The control unit 30 determines whether the defrost condition of the outdoor heat exchanger (not shown) is satisfied by receiving the temperature value detected at the temperature detected by the second temperature sensors 10 and 20, and controlling the control unit 30. An outdoor unit fan 50 which performs automatic defrosting by a signal, and an outdoor heat exchanger (not shown) disposed at the air suction side of the outdoor unit fan 50.

The air conditioner 100 has a four-way valve 70 for switching the cooling and heating states of the indoor unit fan 60 and the air-conditioning combined air conditioner to discharge the heat-exchanged air into the indoor heat exchanger (not shown). More).

Here, the control unit 30 includes an outdoor unit microcomputer (not shown) for controlling the operation of the outdoor unit by receiving temperature signals detected from the first and second temperature sensors 10 and 20, and the outdoor unit microcomputer (not shown). Is connected to the first and second temperature sensors 10 and 20 and receives a sensed temperature value to determine a defrosting operation condition to adjust the defrost frequency.

The controller 30 determines the circulation direction of the refrigerant by switching the four-way valve 70 when the cooling operation or the heating operation, and performs the automatic operation according to the pre-stored algorithm according to the outdoor temperature and the room temperature if the automatic operation command. When the defrosting operation command, the operation frequency of the compressor 40 is set to the defrosting frequency to perform the operation.

FIG. 2 is a graph illustrating a process of sequentially performing the defrosting method of the air conditioner illustrated in FIG. 1, and FIG. 3 is a flow chart of the defrosting method of the air conditioner illustrated in FIG. 1.

The defrosting method of the air conditioner illustrated in FIG. 1 will be described in detail with reference to FIGS. 2 and 3 as follows.

If it is determined that a predetermined time has elapsed after the heating operation of the air conditioner 100 and the operation time of the compressor 40 has elapsed for a predetermined time or more since the heating operation, the control unit 30 controls the first temperature sensor ( It is determined whether the difference T1-T2 between the first temperature T1 detected by 10) and the second temperature T2 detected by the second temperature sensor 20 is greater than or equal to a temperature value within a predetermined range.

Herein, the temperature value within the predetermined range can be set to the fourth temperature T4, and the fourth temperature T4 is any predetermined temperature of 4 ° C to 8 ° C, and preferably 6 ° C. (S10)

When the difference T1-T2 between the first temperature T1 and the second temperature T2 is greater than or equal to the fourth temperature T4, the defrosting operation is started by determining that freezing occurs in the outdoor unit fan 50. That is, when the pipe temperature T1 of the outdoor heat exchanger is lower than or equal to a predetermined temperature, a difference from the outdoor temperature T2 increases, and a difference T1 between the first temperature T1 and the second temperature T2. When -T2 is equal to or greater than the fourth temperature T4, the controller 30 determines that the defrosting operation is started, and switches the four-way valve 70 to a cooling cycle.

After switching to the cooling cycle, the temperature of the outdoor heat exchanger increases when the defrosting operation is started. In addition, when the air conditioner 100 is switched from a heating cycle to a cooling cycle, when the outdoor unit fan 50 and the indoor unit fan 60 are turned on, cold air may flow out of the indoor unit. By the control, the outdoor unit fan 50 and the indoor unit fan 60 are turned off (OFF), and only the compressor 40 is operated. At this time, as the amount of refrigerant flowing to the indoor side is reduced, the amount of refrigerant condensation in the indoor heat exchanger is reduced, and the temperature discharged into the room is lowered. Therefore, the compressor 40 is operated at a predetermined operating frequency (defrost frequency) to complete the defrost while rapidly reducing cold air discharge into the room.

Meanwhile, when the defrosting operation is performed, the temperature of the outdoor heat exchanger rises to melt frost formed on the outdoor heat exchanger. This may be set as the main defrosting operation period Δt1. Referring to FIG. 2, after the main defrosting operation Δt1 is completed, the outdoor unit fan 50 may be removed to remove water formed in the outdoor heat exchanger. Rotate for a predetermined time by setting to strong wind.

As shown in FIG. 2, the section for rotating for a predetermined time in a strong wind state, which is the outdoor unit fan 50, has a predetermined time Δt2 and a defrost section of the defrosting operation period Δt1 + Δt2. It continues for a predetermined time (Δt3) until it is finished. In the embodiment of the present invention shown in Figure 2 can be set to Δt2 and Δt3 to 40 seconds, 60 seconds, respectively, the time that the outdoor unit fan 50 is rotated in a strong wind state is about 100 seconds (Δ t2 + Δt3).

After the outdoor unit fan 50 is rotated for a predetermined time DELTA t2 + DELTA t3 in a strong wind state, the outdoor unit fan 50 returns to the conventional set wind state.

However, in an environment where humidity is high at a temperature of minus zero in winter, a large amount of moisture in the air attaches to the outdoor unit fan 50 during the heating operation of the air conditioner 100, thereby deteriorating the heating performance of the air conditioner 100. Let's do it.

4 is a graph showing the pipe temperature of the indoor heat exchanger measured in a cold humid environment during the heating operation of the conventional air conditioner.

In the low-humidity environment, even in winter, the piping temperature of the indoor unit, which affects the temperature of the air blown out to the indoor side, is continuously taken out at a high temperature of 45 ° C for a long time, When tested in a high environment, for example, outdoor temperature is -5 ℃, relative humidity (RH, 70% to 95%), as shown in A, B of Figure 4, the piping temperature of the indoor unit during the heating operation is The abruptly lowered heating performance of the air conditioner 100 is reduced.

In this case, when the operation of the air conditioner 100 is stopped and the outdoor unit fan 50 is examined, freezing is generated in the outdoor unit fan 50 and the front grill 55.

Therefore, new logic may be added so that defrosting of the air conditioner, in particular, the outdoor unit fan 50 and the front grill 55 may be performed properly even in a high humidity environment at a temperature below freezing in winter.

As shown in FIG. 3, after entering the defrosting operation mode (S20), it is determined whether the pipe temperature T1 of the outdoor unit detected by the first temperature sensor 10 is greater than or equal to the third temperature T3. (S30)

When the pipe temperature T1 of the outdoor unit is greater than or equal to the third temperature T3, adding the step of rotating the outdoor unit fan 50 in a mild wind (S40).

Here, the outdoor unit fan 50 may be rotated for 30 seconds to 120 seconds at a rotational speed of 300 RPM or more and 750 RPM or less in order to rotate the outdoor unit fan 50 in a weak wind.

Further, the third temperature is 6 ° C to 10 ° C, preferably 8 ° C.

After the outdoor unit fan 50 rotates for a predetermined time in the weak wind, defrosting operation is continuously performed, and when the main defrost time ends, the outdoor unit fan 50 is rotated in the strong wind (S50).

However, if the pipe temperature T1 of the outdoor unit is not equal to or greater than the third temperature T3, it is determined whether the main defrost section has been completed after the main defrost time Δt1 has passed (S35).

After the main defrosting section is completed, the outdoor unit fan 50 is rotated by strong wind (S50), and when the main defrosting section is not completed, the pipe temperature T1 of the outdoor unit again exceeds the third temperature (T3). Return to step (S30) to determine the recognition.

On the other hand, during the defrosting operation mode and the strong wind rotation step (S50) of the outdoor unit fan, if the piping temperature of the outdoor heat exchanger is a predetermined temperature or more, or the defrosting operation time elapses a predetermined time, the control unit ends the defrosting operation (S60) The control unit turns on the four-way valve to terminate the defrosting operation and simultaneously drive the load to return to the original heating operation state (S70).

If the outdoor unit fan 50 is blown during the defrosting operation, cold air may flow out to the room. Therefore, the outdoor unit fan 50 may be set to a low wind to rotate for a short time. At the same time, the air blows out from the outdoor heat exchanger through the outdoor unit fan 50 and serves to melt the frost formed.

FIG. 5 is a graph illustrating a pipe temperature of an indoor heat exchanger measured in a cold and humid environment during a heating operation of the air conditioner illustrated in FIG. 1.

As shown in FIG. 5, when tested in a high humidity environment, such as the outdoor temperature at -5 ° C. and the relative humidity (RH) of 70% to 95% at a temperature below zero in winter, the temperature of the air blown out to the indoor side is shown. It can be seen that the piping temperature of the indoor unit affecting the temperature is continuously taken out at a high temperature of 45 ° C for a long time.

That is, unlike A and B shown in FIG. 4, the pipe temperature of the indoor unit is continuously taken out at a high temperature of 45 ° C., which means that the pipe temperature of the indoor unit is not lowered during the heating operation.

6 is a view illustrating a state of an outdoor unit fan and a front grill during a heating operation of a conventional air conditioner, and FIG. 7 is a view illustrating a state of the outdoor unit fan and a front grill during a heating operation of an air conditioner shown in FIG. 1. It is a figure which shows a state.

6 and 7, during the heating operation of the conventional air conditioner 100, frost is generated by freezing of the outdoor unit fan 50 and the front grill 55, but the frost is generated as shown in FIG. 1. During the heating operation of the air conditioner 100, it can be seen that freezing does not occur in the outdoor unit fan 50 and the front grill 55.

Therefore, the pipe temperature of the indoor unit is not lowered during the heating operation, so that no icing occurs in the outdoor unit fan 50 and the front grill 55, so that the outdoor unit fan 50 does not generate resistance. Even when the fan 50 is operated at the same rotation speed, the air volume does not decrease and thus does not occur, and thus the heating operation performance of the air conditioner 100 may be maintained constantly.

The air conditioner and the defrosting method of the air conditioner according to the present invention configured as described above can defrost the outdoor unit fan during the defrosting operation of the air conditioner in a cold and humid environment to maintain the heating performance of the air conditioner. There is.

In addition, by adding a logic to rotate the outdoor unit fan in a mild wind to the control unit, it is possible to prevent the freezing of the outdoor unit fan and the front grill, and the heating performance of the air conditioner is maintained because no resistance occurs in the outdoor unit fan It works.

In addition, since the logic for controlling the outdoor unit fan is added to the control unit without using additional mechanical elements, the freezing of the outdoor unit fan and the front grill can be prevented, resulting in the cost of adding new parts. There is an advantage that does not.

Claims (7)

An outdoor unit fan; An outdoor heat exchanger disposed at an air suction side of the outdoor unit fan; A first temperature sensor detecting a pipe temperature T1 of the outdoor heat exchanger; A second temperature sensor for sensing the outdoor temperature T2; When the outdoor heat exchanger satisfies the defrost condition by receiving the temperature values T1 and T2 detected by the first and second temperature sensors, the defrosting operation is performed, and the pipe temperature of the outdoor heat exchanger is the third during the defrosting operation. And a control unit that rotates the outdoor unit fan when the temperature is above T3. The method according to claim 1, The defrost condition of the outdoor heat exchanger is an air conditioner in which a difference (T1-T2) between a pipe temperature (T1) and the outdoor temperature (T2) of the outdoor heat exchanger is greater than or equal to a fourth temperature (T4). The method according to claim 1 or 2, The controller is configured to rotate the outdoor unit fan at a rotation speed of 300 RPM to 750 RPM when the third temperature T3 is 6 ° C to 10 ° C and the pipe temperature of the outdoor heat exchanger is greater than or equal to the third temperature T3. An air conditioner rotating for 30 seconds to 120 seconds. The method according to claim 2 or 3, The fourth temperature (T4) is an air conditioner of 4 ℃ to 8 ℃ In the defrosting method of an air conditioner comprising an outdoor unit fan and an outdoor heat exchanger disposed on an air intake side of the outdoor unit fan, and performing a defrost operation within a heating operation period. Starting the defrosting operation by switching the air conditioner to a cooling operation mode; And defrosting the outdoor unit fan by rotating the outdoor unit fan when the pipe temperature of the outdoor heat exchanger is greater than or equal to a third temperature (T3) during the defrosting operation. The method according to claim 5, The third temperature is 6 to 10 ℃ defrosting method of the air conditioner. The method according to claim 5 or 6, The defrosting method of the air conditioner in the step of defrosting the outdoor unit fan is rotated for 30 seconds to 120 seconds at a rotation speed of 300 RPM to 750 RPM.

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