KR19990004285A - Defroster of air conditioner and control method - Google Patents

Abstract

The present invention relates to a defrosting device of an air conditioner and a control method thereof, comprising: an outdoor heat exchanger for exchanging outdoor air blown by an outdoor fan; and a compressor for circulating a refrigerant to perform heat exchange in the outdoor heat exchanger. In the air conditioner, the temperature reduction means for sensing the temperature of the outdoor heat exchanger that changes during the heating operation according to the operation of the compressor, and the defrost time if the outdoor heat exchanger temperature detected by the temperature sensing means is below a certain temperature The control means for controlling the defrosting operation by clearing the integration time when the outdoor heat exchanger temperature rises for a predetermined time or more during the integration of the defrosting time, and the refrigerant to perform the defrosting operation under the control of the control means. Four-way valve for converting the flow of the, and to perform the defrosting operation under the control of the control means Compressor driving means for driving the accumulator, and during the integration of the defrosting time, when the outdoor heat exchanger temperature rises instantaneously over a certain temperature due to the noise component flowing into the outdoor pipe temperature sensing means, the integration proceeds with a judgment holding time, and thus normal defrosting. Perform the operation.

Description

Defroster of air conditioner and control method

The present invention relates to a heat pump type air conditioner for performing a heating and cooling operation. In particular, when the temperature of the outdoor heat exchanger is lower than a predetermined temperature, the defrosting time is integrated, and during the integration of the defrosting time, the temperature of the outdoor heat exchanger is higher than the predetermined temperature. The present invention relates to a defrosting apparatus of an air conditioner for controlling the defrosting operation by clearing the integration time when maintained for a predetermined time.

In the conventional air conditioner, as shown in FIGS. 1 and 2, the suction grill member 5 having a plurality of suction ports 3 through which the indoor air is sucked is the front lower part of the indoor main body 1 (hereinafter, referred to as a main body). The discharge port 7 is provided in the upper part of the front surface of the main body 1 to discharge the air sucked through the suction port 3 and heat-exchanged by cold or warm air into the room.

In addition, the discharge port 7 is provided with a vertical wind vane 9 for adjusting the direction of the air discharged into the room through the discharge port 7 up and down and the left and right wind vane 11 for adjusting the left and right, the main body On the front surface of (1), the cover member 13 is fixed to the interior of the indoor unit and protects the interior. At the lower side of the cover member 13, the operation mode of the air conditioner (automatic, cooling) , Dehumidification, blowing, heating, etc.) and a start / stop of operation, and an operation unit 15 for adjusting the air volume and the wind direction of the air discharged through the discharge port 7.

As shown in FIG. 2, a filter member 17 is installed inside the suction grill member 5 to filter foreign substances such as dust floating in the indoor air sucked through the suction port 3. The inside of the filter member 17 is provided with a straight indoor heat exchanger 19 so as to heat-exchange the indoor air filtered by the filter member 17 to cold or warm air by evaporative miscellaneous heat of the refrigerant.

In addition, the upper part of the indoor heat exchanger 19 sucks indoor air through the suction port 3 and simultaneously discharges air heat-exchanged in the indoor heat exchanger 19 to the room through the discharge port 7. A blower fan 23 (hereinafter, referred to as an indoor fan) that rotates as the fan motor 21 is driven is installed, and the suction port is provided at the same time as the indoor fan 23 is covered with an outer side of the indoor fan 23. The duct member 25 which guides the flow of the air which is sucked in through (3) and discharged to the said discharge port 7 is provided.

When the air conditioner configured as described above is an inverter air conditioner that is also used for both heating and cooling, the four-way valve 51 is turned on during heating so that the refrigerant is shown by the dotted line (-) in FIG. The valve 51 → the indoor heat exchanger 37 → the expansion valve 53 → the heating expansion valve 54 → the outdoor heat exchanger 55 → the four-way valve 51 → the compressor 59.

On the other hand, during cooling, the four-way valve 51 is turned off so that the refrigerant is shown by the solid line (→) in FIG. 3, and the compressor 59 → the four-way valve 51 → the outdoor heat exchanger 55 → the one-way valve 56. ) → expansion valve (53) → indoor heat exchanger (37) → four-way valve (51) → compressor (59).

At this time, the four-way valve 51 adjusts the flow path so that the refrigerant circulates in the solid line (→) when off, and adjusts the flow path so that the refrigerant circulates in the dotted line (-) when on.

In the air conditioning and air conditioner configured as described above, when the user operates the remote controller or the control unit 15 to select a desired operation mode (for example, heating), and then turns on the operation key, the set temperature (Ts) and the room temperature When the set temperature Ts is higher than the room temperature Tr by comparing (Tr), the compressor is driven by determining the operating frequency of the compressor according to the difference between the set temperature (Ts) and the room temperature (Tr).

When the compressor is driven, as the refrigerant is shown by a dotted line (-) in Fig. 3, the compressor 59 → the four-way valve 51 → the indoor heat exchanger 19 → the expansion valve 53 → the expansion valve for heating ( 54) → the outdoor heat exchanger (19) → the four-way valve (51) → the compressor (59) is circulated in order to start the heating of the indoor heat exchanger (19), depending on the temperature of the indoor heat exchanger (19) changes at this time The driving of the indoor fan 23 is controlled.

If the temperature of the indoor heat exchanger 19 is lower than a predetermined temperature (about 27 ° C.), the indoor fan 23 is stopped to prevent cold air from being discharged to the room at the beginning of heating. If the temperature is equal to or higher than a predetermined temperature (about 27 ° C.), the indoor fan 23 is driven.

When the indoor fan 23 is driven, the indoor air sucked into the main body 1 through the suction port 3 passes through the indoor heat exchanger 19 while the warm air is caused by the latent heat of evaporation of the refrigerant flowing in the indoor heat exchanger 19. Heat exchanged by the heat exchanger, and the warm air heat-exchanged in the indoor heat exchanger 19 is guided to the upper portion and discharged into the room through the discharge hole 7, and the warm air discharged through the discharge hole 7 is the up-down wind vane 9 and the left-right wind direction Air conditioning is performed up and down or left and right according to the wind direction angle of the wing 11 to perform the indoor heating.

According to the heating cycle as described above, the warm air heat exchanged in the indoor heat exchanger 19 is guided to the upper portion and discharged into the room through the discharge hole 7, and the warm air discharged through the discharge hole 7 is a vertical wind vane 9. And the air direction is adjusted up and down or left and right according to the wind direction angle of the left and right wind direction blades 11 to perform the indoor heating.

When the heating operation is performed as described above, the outdoor heat exchanger 35 is discharged to the outside by cooling the air blown from the outside by heat exchange by the latent heat of evaporation of the refrigerant in the outdoor heat exchanger 35. The frost is formed in the frost, and as the frost is formed over time, the ice becomes thick and the heat exchange capacity of the outdoor heat exchanger 35 not only decreases, but the power consumption increases due to the decrease in the heating efficiency. .

In addition, the frost formed on the outdoor heat exchanger 35 causes freezing of the outdoor heat exchanger 35, which causes a failure of the compressor 39.

Therefore, in the conventional air conditioner, the pipe temperature Top of the outdoor heat exchanger 35 is not shown after 30 minutes have elapsed since the compressor 35 was operated during the heating operation of the air conditioner to prevent this. If the outdoor piping temperature (Top) falls below a certain temperature (about, -2 ℃) by sensing the sensor input unit, the defrosting time is accumulated to start the defrosting operation.

At this time, when the defrost accumulation time has elapsed for a predetermined time (about 10 minutes), it is determined that the freezing phenomenon occurs in the outdoor heat exchanger 35, and the outdoor fan 37 and the indoor fan 23 are stopped for heating operation. While stopping, the four-way valve 31 is turned off to switch the air conditioner to the cooling operation.

Accordingly, the refrigerant is compressed by the compressor 39 → four-way valve 31 → outdoor heat exchanger 35 → one-way valve 36 → expansion valve 33 → indoor heat exchanger 19 → four-way valve 31 → compressor ( A defrosting operation for removing frost formed on the outdoor heat exchanger 35 is performed by forming a cooling cycle circulated in the order of 39).

On the other hand, if the temperature Top of the outdoor heat exchanger 35 rises above a certain temperature or the operation mode is changed to a mode other than heating while integrating the defrost time, the defrost time is cleared to zero.

However, in the conventional defrosting operation method, the temperature sensing becomes unstable due to the noise component introduced into the sensor input part of the outdoor heat exchanger 35 during the defrosting time integration, and the temperature rises by a certain temperature instantaneously. If this occurs, the defrost time is cleared, there was a problem that normal defrosting operation is impossible.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, the determination time of the outdoor heat exchanger temperature during the integration of the defrosting time is instantaneously risen by a certain temperature by a noise component flowing into the outdoor pipe temperature sensing means. It is an object of the present invention to provide a defrosting apparatus and a control method of the air conditioner to perform the normal defrosting operation since the integration proceeds.

In order to achieve the above object, a defrosting apparatus of an air conditioner according to the present invention includes an outdoor heat exchanger for exchanging outdoor air blown by an outdoor fan, and an air including a compressor for circulating a refrigerant to perform heat exchange in the outdoor heat exchanger. In the conditioner, the temperature sensing means for sensing the temperature of the outdoor heat exchanger that changes during the heating operation according to the operation of the compressor, and the defrost time if the outdoor heat exchanger temperature detected by the temperature reducing means is below a certain temperature. Control means for controlling the defrosting operation by clearing the integration time when the temperature of the outdoor heat exchanger during the integration of the defrosting time is increased for a predetermined time or more during the defrosting time, and the defrosting operation according to the control of the control means. Four-way valve to change the flow, and to perform the defrosting operation under the control of the control means It is characterized by being a compressor drive means for driving the compressor group.

In addition, the defrosting control method of the air conditioner according to the present invention comprises a heating step of performing a heating operation by discharging the warm air heat exchanged in the indoor heat exchanger in accordance with the operation of the compressor and the indoor fan, and during the heating operation in the heating step A first temperature discrimination step of determining whether the temperature of the outdoor heat exchanger is changed to be below a predetermined temperature, an integration step of integrating a defrost time if the outdoor heat exchanger temperature is less than or equal to a predetermined temperature in the first temperature discrimination step; A second temperature judging step for determining whether the outdoor heat exchanger temperature is above a predetermined temperature during integration of the defrost time in an integration step; and if the outdoor heat exchanger temperature is kept above a predetermined temperature for a predetermined time in the second temperature judging step, integration is performed. When the clear step for clearing the time and the outdoor heat exchanger temperature in the second temperature discrimination step are not higher than a predetermined temperature and the defrost accumulation time is predetermined After passing, it is characterized in that the defrosting operation step for removing the frost formed on the outdoor heat exchanger by driving the four-way valve and the compressor.

1 is a perspective view showing an indoor unit of a conventional air conditioner,

2 is a longitudinal cross-sectional view of FIG.

3 is a cooling and heating cycle of a general air conditioner,

4 is a control block diagram of a defrosting apparatus of an air conditioner according to an embodiment of the present invention;

5A and 5B are flowcharts showing a defrost control operation procedure of the air conditioner according to the present invention.

Explanation of symbols for the main parts of the drawings

3: inlet port 7: outlet port

19: indoor heat exchanger 23: indoor fan

31: Four-way valve 35: Outdoor heat exchanger

37: outdoor fan 39: compressor

100: power supply means 102: operation operation means

104: control means 106: room temperature detection means

108: indoor piping temperature sensing means 110: outdoor piping temperature sensing means

120: wind direction control means 121: wind direction motor

122: compressor driving means 124: outdoor fan motor driving means

126: indoor fan motor driving means 128: four-way valve driving means

130: display means

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

As shown in FIG. 4, the power supply means 100 converts a commercial AC voltage supplied from an AC power supply terminal (not shown) into a predetermined DC voltage required for the operation of the air conditioner, and outputs the same. ) Is the operation mode of the air conditioner (automatic, cooling, dehumidification, blowing, heating, etc.), the amount of air discharged through the discharge port 7 (strong wind, weak wind, breeze, etc.) and the desired temperature (Ts; And a plurality of function keys for selecting a temperature) and an operation key for inputting an operation start signal and an operation stop signal of the air conditioner.

And, the control means 104 is applied to the DC voltage output from the power supply means 100 to initialize the air conditioner, as well as the air conditioning in accordance with the operation selection signal input by the operation operation means (102) As a microcomputer for controlling the overall operation of the machine, the control means 104 determines whether the defrosting operation is performed according to the piping temperature and the defrost integration time of the outdoor heat exchanger 35, and the outdoor heat exchanger 35 during integration of the defrost time. When the temperature rises above a certain temperature, the counter is counted and cleared so that the integration proceeds with the judgment retention time.

The indoor temperature detecting means 106 is sucked through the inlet port 3 to control the indoor temperature to the temperature Ts set by the user by the driving operation means 102 to perform the heating operation of the air conditioner. The temperature Tr of the indoor air is sensed, and the indoor pipe temperature detecting means 108 controls the pipe temperature of the indoor heat exchanger 19 that changes during the heating operation of the air conditioner, that is, the indoor heat exchanger 19. Sensing the refrigerant temperature passing through, the outdoor pipe temperature detecting means 110 is the refrigerant temperature passing through the pipe temperature of the outdoor heat exchanger 35 that changes during the heating operation of the air conditioner, that is, the outdoor heat exchanger 35. The temperature is sensed and output to the control means 104.

In addition, the wind direction control unit 120 controls the drive of the wind direction motor 121 to vertically and horizontally adjust the direction of the discharged air so that the air discharged through the discharge port 7 is evenly spread throughout the room, and the compressor driving means ( 122 is output from the control means 104 in accordance with the difference between the temperature Ts set by the user by the driving operation means 102 and the room temperature Tr sensed by the room temperature sensing means 106. The compressor 39 is driven and controlled by receiving the control signal.

The outdoor fan motor driving means 124 is controlled according to the difference between the temperature Ts set by the user by the driving operation means 102 and the room temperature Tr sensed by the indoor temperature sensing means 106. Receiving a control signal output from the means 104 to drive the outdoor fan 37 by controlling the rotation speed of the outdoor fan motor 125 to blow the air heat-exchanged in the outdoor heat exchanger 35 to the outside, and drive the indoor fan 37, The fan motor driving means 126 receives the control signal output from the control means 104 according to the air volume set by the user by the driving operation means 20 (air cooled by the indoor heat exchanger 37). Or controlling the rotation speed of the indoor fan motor 21 to blow the warm air into the room.

In addition, in the figure, the four-way valve driving means 128 is a control output from the control means 104 to convert the flow of the refrigerant in accordance with the operating conditions (cooling or heating) input by the driving operation means (102) In response to the signal, the four-way valve 31 is controlled to be turned on and off, and the display means 130 controls the operation selection mode (automatic or cooling) input by the driving operation means 102 under the control of the control means 104. (Dehumidification, blowing, heating, etc.) and the defrosting display lamp indicating the defrosting operation / completion of defrosting, as well as displaying the operating state of the air conditioner.

Hereinafter, the effect of the defrosting device of the air conditioner and the control method configured as described above will be described.

5A and 5B are flowcharts showing the defrost control operation procedure of the air conditioner according to the present invention, in which S denotes a step (STEP) in FIGS. 5A and 5B.

First, when power is applied to the air conditioner, the power supply means 100 converts a commercial AC voltage supplied from an AC power stage (not shown) into a predetermined DC voltage required for driving the air conditioner, thereby driving each circuit and control means ( Output to 104).

Therefore, in step S1, the DC voltage output from the power supply means 100 is input from the control means 104 to initialize the air conditioner.

At this time, the user inputs the operation mode (for example, heating) and the set temperature (Ts), the set air volume of the desired air conditioner by operating the operation operation means 102, and then press the operation key, the operation operation means ( From the 102, an operation selection signal and an operation start signal (hereinafter referred to as operation signal) are input to the control means 104.

Accordingly, in step S2, the control means 104 determines whether the driving signal is input from the driving operation means 102, and maintains the air conditioner in the operation standby state when the driving signal is not input (NO). The operation of step S2 and below is repeated.

As a result of the discrimination in step S2, when an operation signal is input (YES), the control means 104 determines whether the operation condition input by the operation operation means 102 is a heating operation, in step S3. If it is not the heating operation (NO), the process proceeds to step S31, returns to the step S3 while performing the cooling or dehumidifying operation of the air conditioner, and repeats the operation of step S3 or less.

As a result of the discrimination in step S3, in the case of heating operation (YES), in order to perform heating operation of the air conditioner, in step S4, the control means 104 controls the control signal for controlling the four-way valve 31 in all directions. Output to the valve drive means (128).

Accordingly, in the four-way valve driving means 128, the refrigerant is turned on by the four-way valve 31 under the control of the control means 104, and the refrigerant flows from the compressor 39 to the four-way valve 31 to the indoor heat exchanger 19 to the expansion valve. (33) → heating expansion valve (34) → outdoor heat exchanger (35) → four-way valve (31) → compressor (39).

At this time, when the temperature (Tip) of the indoor heat exchanger (19) is detected by the indoor pipe temperature detecting means (108), the control means (104) detects the indoor pipe temperature by the indoor pipe temperature detecting means (108). (Tip) is inputted and converted into digital to determine whether the indoor piping temperature (Tip) is less than the predetermined temperature (Tl; preheating piping temperature to prevent cold air discharge during the initial heating, about 27t).

As a result of the determination in step S5, when the indoor piping temperature Tip is less than the predetermined temperature Tl (YES), it is determined that it is a temperature condition in which cold air can be discharged into the room, and the indoor fan 23 is not driven. Proceeding to step S6 to drive the outdoor unit first to heat the indoor heat exchanger 19, the control means 104 determines whether the outdoor unit is in an on condition.

The condition that the outdoor unit is turned on is when the indoor temperature Tr sensed by the indoor temperature detecting means 106 is smaller than the temperature Ts set by the user.

As a result of the determination in step S6, when the outdoor unit is not in the on condition (NO), the operation returns to step S5 while waiting for the operation operation, and repeats the operation under step S5, and when the outdoor unit is in the on condition (YES In this case), the control means 104 determines the operating frequency of the compressor 39 and the rotation speed of the outdoor fan motor 125 according to the difference between the room temperature Tr and the set temperature Ts. A control signal for driving the 39 and the outdoor fan 37 is output to the compressor driving means 122 and the outdoor fan motor driving means 124.

Accordingly, the compressor driving means 122 drives the compressor 39 according to the driving frequency determined by the control means 104, and the outdoor fan motor driving means 124 uses the outdoor speed according to the rotation speed determined by the control means 104. The fan 37 is driven.

At this time, in step S8, when the temperature (Tip) of the indoor heat exchanger (19) heated during the circulation of the refrigerant by the drive of the compressor (39) is sensed by the indoor pipe temperature detecting means (108), the control means (104) When the indoor pipe temperature detected by the indoor pipe temperature detecting means 108 is determined to be equal to or higher than the predetermined temperature Tl, and the indoor pipe temperature Tip is not equal to or higher than the predetermined temperature Tl (NO). ), It is determined that it is a temperature condition in which cold air can be discharged into the room, and the flow returns to step S7 to repeat the operation of step S7 or less.

As a result of the determination in step S8, when the indoor piping temperature Tip is equal to or higher than the predetermined temperature Tl (YES), it is determined that it is a temperature condition in which cold air is not discharged to the room, and the control means 104 proceeds to step S9. The control signal for driving the indoor fan 23 is output to the indoor fan motor driving means 126.

Accordingly, the indoor fan motor driving means 126 drives the indoor fan 23 by controlling the rotation speed of the indoor fan motor 21 according to the set air volume.

When the indoor fan 23 is driven, the refrigerant compressed by the compressor 39 into the gas of high temperature and high pressure flows into the indoor heat exchanger 19 through the four-way valve 31, and the indoor heat exchanger 19 ) Heat exchanges the gas refrigerant compressed to high temperature and high pressure with air blown by the indoor fan 23 and cools the refrigerant to room temperature and high pressure refrigerant. Heats through the warm air while passing.

The air heat-exchanged with the warm air in the indoor heat exchanger 19 is moved upward and downward or left and right depending on the wind direction angles of the upper and lower wind vanes 9 and the left and right wind vanes 11 rotatably installed at the discharge port 7. Heat the room while adjusting.

At this time, the low temperature and high pressure liquid refrigerant liquefied in the indoor heat exchanger (19) passes through the expansion valve (33) and the heating expansion valve (34) to expand to the evaporation pressure while being decompressed to a low-temperature low-pressure free refrigerant to the outdoor heat exchanger ( 35).

Accordingly, the outdoor heat exchanger 35 receives the low-temperature low-temperature free refrigerant depressurized by the expansion valve 33 and the heating expansion valve 34 to heat exchange the air blown by the outdoor fan 37 by the latent heat of evaporation of the refrigerant. By cooling, the low-temperature low-pressure gas refrigerant cooled in the outdoor heat exchanger (35) is sucked back into the compressor (39) through the four-way valve 31, as shown by the dotted line (-) of Figure 3, repeated Perform indoor heating while forming a circulating heating cycle.

As described above, when the heating operation is performed for a predetermined time, when the air blown by the outdoor fan 37 is cooled by heat exchange by cooling by the latent heat of evaporation of the refrigerant in the outdoor heat exchanger 35, the outdoor by cold air discharged to the outside The frost is formed on the surface of the heat exchanger 35, and the frost formed on the surface becomes thicker with time, causing freezing of the outdoor unit.

Accordingly, in order to prevent freezing of the outdoor unit, the defrosting operation condition according to the temperature Top of the outdoor heat exchanger 35 should be checked. In step S11, it is determined whether the compressor 39 is on, and the compressor 39 If not (ON), the flow returns to step S10 to repeat the operation of step S10 or less.

As a result of the discrimination in step S11, when the compressor 39 is on (YES), the flow advances to step S12, whereby the control means operates a predetermined time (t3; 30 minutes), and if the predetermined time t3 has not elapsed (NO), the process returns to the step S10 and repeats the steps S10 and below.

As a result of the discrimination in step S12, when the predetermined time t3 has elapsed (YES), the compressor 39 operates and 30 minutes have elapsed. When the temperature Top of 35 is sensed by the outdoor pipe temperature detecting means 110, the control means 104 receives analog data of the outdoor pipe temperature Top and converts it into digital to convert the outdoor pipe temperature T to It is determined whether it is below a certain temperature (T2; pipe temperature at which frost forms on the outdoor heat exchanger during heating operation).

As a result of the determination in step S13, when the outdoor piping temperature Top is not equal to or lower than the predetermined temperature T2 (NO), no frost is formed in the outdoor heat exchanger 35, and the process returns to step S10. The operation of step S10 or less is repeated while continuing heating operation.

On the other hand, when the determination result in step S13 is that the outdoor piping temperature Top is below the predetermined temperature T2 (YES), frost is formed in the outdoor heat exchanger 35, and therefore, the defrosting operation is performed in step S14. To start the defrost time begins to accumulate.

At this time, if the outdoor heat exchanger 35 temperature Top rises above a predetermined temperature T2 or the operation mode is changed to a mode other than heating during integration of the defrosting time, the defrosting integration time must be cleared, so that the outdoor piping at step S15 is performed. It is determined whether the temperature Top is above the predetermined temperature T2.

As a result of the determination in step S15, when the outdoor piping temperature Top is not equal to or higher than the predetermined temperature T2 (NO), the flow advances to step S16 to determine whether the outdoor piping temperature Top is equal to or less than the predetermined temperature T2 for a predetermined time. (t4; it is determined whether frost is formed in the outdoor heat exchanger and freezing occurs, about 10 minutes). If the predetermined time t4 has not elapsed (NO), the process returns to step S15 and the outdoor piping The operation of step Sl5 or less is repeated while continuously detecting the temperature Top.

As a result of the discrimination in step S16, when a predetermined time t4 has elapsed (YES), frost is formed on the outdoor heat exchanger 35 and freezing occurs, so that defrosting operation of the air conditioner is performed. In step S17, the control means 104 outputs a control signal for stopping the outdoor fan motor 125 and the indoor fan motor 21 to the outdoor fan motor driving means 124 and the indoor fan motor driving means 126. At the same time, a control signal for controlling the four-way valve 31 is output to the four-way valve driving means 128, and the defrost display lamp is turned on through the display means 130 to display the defrosting operation state.

Therefore, the outdoor fan motor driving means 124 stops the driving of the outdoor fan 37 by stopping the outdoor fan motor 125 under the control of the control means 104, and the indoor fan motor driving means 126. Under the control of the control means 104, the indoor fan motor 21 is stopped to stop the driving of the indoor fan 23. In the four-way valve driving means 128, the four-way valve 31 is controlled by the control means 104. Off).

When the four-way valve 51 is off, the refrigerant is compressed from the compressor 39 to the four-way valve 31 to the outdoor heat exchanger 35 to the one-way valve 36 to the expansion valve 33 to the indoor heat exchanger 19. Defrost operation is performed to remove frost on the outdoor heat exchanger 35 by stopping the outdoor fan 37 and the indoor fan 23 while forming a cooling cycle circulated in the order of the valve 31 → the compressor 39. End the operation.

As a result of the determination in step S15, when the outdoor pipe temperature Top is above a predetermined temperature T2 (YES), the outdoor pipe temperature Top is influenced by the noise component flowing into the outdoor pipe temperature sensing means 110. In order to determine whether the temperature sensing is unstable and the temperature has risen more than the predetermined temperature T2, the control unit 104 proceeds to step S20. The control means 104 determines that the outdoor piping temperature T is greater than or equal to the predetermined temperature T2 for a predetermined time t5; 1 minute).

As a result of the determination in step S20, when the predetermined time t5 has not elapsed (NO), it is determined that the outdoor piping temperature Top has risen momentarily by the noise component and ignores the outdoor piping temperature Top. Proceeding to step S16, the operation of step S16 or less is repeated.

On the other hand, as a result of the determination in step S20, when the predetermined time t5 has elapsed (YES), the outdoor piping temperature Top has risen above the predetermined temperature T2 rather than being instantaneously changed by the noise component. Judgment is made, the process proceeds to step S21, and the control means 104 returns to the step S13 while clearing the defrost accumulation time, and repeatedly performs the operation of step S13 or less.

According to the defrosting apparatus and control method of the air conditioner according to the present invention as described above, the temperature of the outdoor heat exchanger during the integration of the defrosting time is instantaneously above a certain temperature by a noise component introduced into the outdoor pipe temperature sensing means. When the ascension proceeds without accumulating the defrost time, the integration proceeds with the deferred retention time, and thus the normal defrosting operation is performed.

Claims (2)

An air conditioner including an outdoor heat exchanger for exchanging outdoor air blown by an outdoor fan, and a compressor for circulating a refrigerant to perform heat exchange in the outdoor heat exchanger, wherein the air conditioner changes during heating operation according to the operation of the compressor. Defrosting time is integrated when the temperature sensing means for sensing the temperature of the outdoor heat exchanger and the outdoor heat exchanger temperature detected by the temperature reducing means is below a predetermined temperature, and the outdoor heat exchanger temperature during the integration of the defrosting time is above a certain temperature. Control means for controlling the defrosting operation by clearing the integration time when rising for a predetermined time, Four-way valve for converting the flow of the refrigerant to perform the defrosting operation under the control of the control means, Defrosting operation under the control of the control means Compressor driving means for driving the compressor to perform Defroster of air conditioner. The heating step of discharging the warm air exchanged by the indoor heat exchanger in accordance with the operation of the compressor and the indoor fan to perform the heating operation, and the temperature of the outdoor heat exchanger which changes during the heating operation in the heating step is sensed to be below a predetermined temperature. A first temperature discrimination step for determining a step; an integration step for integrating a defrost time if the outdoor heat exchanger temperature is less than a predetermined temperature in the first temperature discrimination step; and the outdoor heat exchanger temperature during integration of a defrost time in the integration step A second temperature discrimination step for determining whether the temperature is above a predetermined temperature, a clear step for clearing integration time if the temperature of the outdoor heat exchanger is greater than or equal to the predetermined temperature for a predetermined time in the second temperature discrimination step, and an outdoor at the second temperature discrimination step If the heat exchanger temperature is not above a certain temperature and the defrost accumulation time passes a predetermined time, the four-way valve and the compressor are operated to exchange the outdoor heat. Defrosting control method of an air conditioner which is characterized by being a defrosting operation step of removing the frost on the implantation.