KR100407048B1 - Method of controlling defrost for refrigerator - Google Patents

Abstract

The disclosed invention relates to a defrosting control method of a refrigerator capable of performing a defrosting operation according to a refrigerator internal temperature and a compressor operating time. The defrosting control method of the refrigerator according to the present invention sets the first defrosting condition depending on the compressor operating time and the second defrosting condition depending on the internal temperature of the refrigerating chamber and the compressor operating time, and any one of the first and second defrosting conditions. If applicable, characterized in that it comprises the step of performing a defrosting operation to remove frost formed on the evaporator.

According to the present invention, the defrosting operation can be performed in the case where the inside temperature of the refrigerating chamber is more than a certain temperature and the compressor operating time is more than the predetermined time in parallel with the operation of performing the defrosting operation only in accordance with the compressor operating time. Even if the frost is excessively implanted in a situation that can maintain a good heat exchange efficiency between the circulating air and the evaporator, as a result there is an effect that can prevent excessive rise in the internal temperature of the refrigerator compartment. In addition, since the present invention is carried out in a range that suppresses unnecessary defrosting operation as much as possible, it is possible to effectively perform defrosting on the evaporator without wasting power consumption.

Description

Defrost control method of refrigerator {METHOD OF CONTROLLING DEFROST FOR REFRIGERATOR}

The present invention relates to a defrosting control method of a refrigerator, and more particularly, to a defrosting control method of a refrigerator to perform the defrosting operation according to the temperature of the refrigerating chamber and the operation time of the compressor.

In general, the refrigerator forcibly supplies cold air generated from an evaporator of a refrigeration cycle to a storage compartment by using a fan, thereby preventing corruption of the stored food and maintaining freshness for a long time.

The conventional refrigerator includes a main body in which the freezer compartment and the refrigerating compartment are partitioned by an intermediate partition, a door hinged to the main body to open and close the freezer compartment and the refrigerating compartment, respectively, and a refrigerating cycle driving element mounted to the main body.

Evaporator and fan with defrost heater are installed at the back of main body to generate cold air and supply it to freezer and refrigerating chamber. One evaporator and fan are installed to distribute and supply cold air to freezer and refrigerating chamber. Two evaporators and two fans are provided, which can be largely classified into a method of independently supplying cold air to each chamber to perform a cooling operation. Either way, the defrost heater placed on the evaporator is to remove the frost formed on the evaporator.

When power is supplied to a conventional refrigerator configured as described above and a refrigerating cycle such as a fan and a compressor is driven, air in the freezer compartment and the refrigerating compartment is sucked to the evaporator side, and heat exchange occurs as it passes through the evaporator to generate cold air. It is guided to the freezer compartment and the refrigerating chamber by the blowing force and discharged into the refrigerator, and this cold air circulation process is continuously performed.

At this time, the air circulating in the freezer compartment and the refrigerating compartment flows into the evaporator in a state containing moisture in the refrigerator, so that the moisture contained in the air forms on the surface of the evaporator to form a frost. Therefore, defrost heater is operated to remove frost by operating defrost heater.

The defrosting operation is performed by the control of the microcomputer that controls the refrigerator as a whole. The defrosting condition for determining whether the defrosting operation is set in advance and the defrosting heater is driven when the defrosting condition is satisfied.

In a conventional refrigerator, the compressor operation time is accumulated cumulatively using a timer, and when the accumulated compressor operation time reaches a preset time, it is determined that the defrost condition is satisfied, and the defrosting heater is driven to start the defrosting operation. When the defrost temperature detected by the sensor, that is, the surface temperature of the evaporator reached the preset temperature, the defrost heater was stopped and then cooled according to the normal operation, that is, the internal temperature of each room. That is, conventionally, defrosting operation was performed depending on the compressor operation time.

However, even when the compressor operation time does not reach the set time and the defrosting condition is not satisfied, the frosting of the evaporator can be made by various factors. The amount of implantation may vary.

Nevertheless, it does not satisfy the defrosting condition because it only depends on the compressor operation time corresponding to the operation rate of the refrigerator. As a result, the heat exchange efficiency of the deteriorated, and as a result, the internal temperature of each chamber rapidly increased, there was a problem that the quality of the food stored in the deterioration.

This problem is more prominent in the refrigerating chamber with a high frequency of use and a relatively high internal temperature.

Meanwhile, in the independent cooling system having two evaporators and fans, the defrosting time of the refrigerating compartment evaporator is shorter (6-8 hours) than the defrosting time of the freezer compartment evaporator, so that the heat exchange efficiency of the refrigerating compartment evaporator is not reduced. However, even in this case, it is difficult to effectively solve the above problems. In this regard, the method of shortening the setting time applied to the defrosting condition focuses only on the above problems, so that defrosting operation is frequently performed more than necessary, such as the case where the amount of defrosting of the evaporator is not much, resulting in an increase in power consumption. It causes another problem.

Therefore, defrosting is performed according to general defrosting conditions when there is not much amount of defrosting in the evaporator, and defrosting is performed according to separate defrosting conditions when the amount of defrosting in the evaporator has a large amount of defrosting due to temporary opening and closing of the door. In parallel, there is an urgent need for a method of maintaining a good heat exchange efficiency of the evaporator at all times.

An object of the present invention is to perform a defrosting operation according to the inside temperature of the refrigerator compartment and the compressor operation time even before reaching the defrosting cycle to maintain a good heat exchange efficiency of the evaporator to prevent excessive rise of the inside temperature of the refrigerator compartment. To provide a control method.

1 is a control block diagram of a refrigerator according to the present invention.

2 is a view showing the operating characteristics of each part according to the present invention.

3 is a flowchart illustrating a control method of a refrigerator according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: key input unit 20: high temperature detection unit

30: operation time integration unit 40: control unit

50: fan motor drive unit 60: compressor drive unit

70: defrost heater driving unit 80: defrost sensor

An object of the present invention as described above, in the defrosting control method of the refrigerator, the first defrost condition depending on the compressor operation time, the internal temperature of the refrigerating chamber and the second defrost condition depending on the compressor operating time, If any one of the two defrosting conditions is achieved by performing a defrosting operation to remove frost formed on the evaporator.

The second defrosting condition is characterized in that it does not depend on the first defrosting condition but acts individually.

In addition, the second defrosting condition is characterized in that the compressor operation time when the internal temperature of the refrigerating chamber is higher than the set temperature and the internal temperature of the refrigerating chamber is higher than the set temperature.

The setting time may be shorter than a first setting time for satisfying the first defrosting condition.

The set temperature is higher than a first set temperature for setting a driving condition of a refrigerating fan motor, and the fan motor is turned on at the upper limit of the first set temperature and the fan motor is turned off at the lower limit of the first set temperature. It features.

The temperature difference between the set temperature and the first set temperature is greater than the temperature difference between the upper limit value and the lower limit value of the first set temperature.

In addition, when two evaporators are provided corresponding to the freezer compartment and the refrigerating compartment, the first and second defrosting conditions are characterized in that an evaporator for supplying cold air to the refrigerating compartment is provided.

The present invention includes a first integration step of integrating the compressor operating time in a first defrosting condition and a second integration step of integrating a compressor operating time in a second defrosting condition, wherein the first and second integration steps are dependent on each other. It is characterized in that it is carried out individually.

The method may further include adding the compressor operation time under the first defrost condition and the compressor operation time under the second defrost condition, and performing the defrosting operation when the combined compressor operation time is equal to or longer than a predetermined time. .

The defrosting operation may be performed when the sum of the compressor operating times is equal to or greater than the first predetermined time for satisfying the first defrosting condition.

The refrigerator of the present invention is provided with a refrigerating compartment and a freezing compartment for storing food in a main body, and having a door for opening and closing each chamber, and having a refrigeration cycle component for generating cold air and supplying it to each chamber. Moreover, the compressor of a refrigeration cycle, a condenser, an electrical equipment box, etc. are installed in the machine room formed in the lower part of the main body.

In addition, an evaporator is connected to the refrigeration cycle to generate cold air at the rear of the freezing chamber, and a blowing fan is installed to be positioned above the evaporator. Here, one evaporator and a blower fan may be used or two evaporators and a blower fan may be provided to independently perform the cooling operation of each chamber.

The present invention is directed to an evaporator for supplying cold air to a refrigerating chamber. If the defrosting condition of any one of the first defrosting condition depending on the compressor operation time and the second defrosting condition depending on the compressor operation time is determined, Perform defrosting operation using. Here, the first defrosting condition is to perform defrosting operation according to the compressor operation time as before, and the second defrosting condition is defrosting operation in case the heat exchange efficiency is low due to excessive amount of frost on the evaporator even if the first defrosting condition is not satisfied. To do this. In fact, the first defrosting condition is to perform defrosting operation periodically every set time (6-8 hours) of the compressor operation time corresponding to the operation rate of the refrigerator, while the second defrosting condition is that the refrigerator internal temperature is kept above the set temperature. Under the condition that the compressor operation time is maintained for a certain time to perform the defrost operation unspecifically.

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

1 is a control block diagram of a refrigerator according to the present invention, Figure 2 is a view showing the operation characteristics of each part according to the present invention.

Referring to FIG. 1, a key input unit 10, an internal temperature detecting unit 20, and a defrost sensor 80 are connected to an input terminal of the controller 40, and an operation time integration unit 30 is connected to an output terminal of the controller 40. The fan motor driver 50, the compressor driver 60, and the defrost heater driver 70 are connected.

The key input unit 10 includes a plurality of keys for input of a user, including setting of a driving mode, and applies a corresponding key signal according to a key input to the controller 40. The internal temperature detecting unit 20 is provided with a temperature sensor (not shown) for detecting the temperature of the freezer compartment and the refrigerating compartment to apply the detected internal temperature of the chamber to the controller 40.

The fan motor driving unit 50 drives the blower fan according to the control of the controller 40. When two evaporators and a blower fan are provided, operating conditions of the freezer compartment fan motor and the refrigerating compartment fan motor depend on the internal temperature of each chamber. different.

The compressor driving unit 60 operates the compressor under the control of the control unit 40, and the operation time integrating unit 30 accumulates the compressor operating time under the control of the control unit 40 and controls the integrated compressor operation time. 40). In particular, the operation time integrating unit 30 performs an operation of integrating the compressor operating time in the second defrosting condition separately from the operation of integrating the compressor operating time in the first defrosting condition.

The defrost heater driving unit 70 drives the defrost heater to defrost the evaporator under the control of the control unit 40 during the defrosting operation, and when the defrost heater is provided with two evaporators, the drive control of the defrost heater separately provided for each evaporator is independently controlled. Done. In addition, the defrost sensor 80 is also installed adjacent to each evaporator detects the defrost temperature, that is, the surface temperature of the evaporator and provides it to the control unit 40.

When the compressor operation time under the first defrosting condition reaches the set time (6 hours), the controller 40 performs a defrosting operation to remove frost formed on the evaporator by operating the defrost heater and independently of the first defrosting operation. Even if the defrosting condition is not satisfied, if the operating temperature of the refrigerating chamber in the second defrosting condition is above a certain temperature and the inside temperature of the refrigerating compartment is above a certain temperature, the frost is excessively formed on the evaporator. The defrosting operation is performed by operating the defrost heater by judging that it is in an intact condition. The setting time (2 hours) under the second defrosting condition is preferably set shorter than the setting time (6 hours) under the first defrosting condition.

Referring to FIG. 2, when the refrigerator compartment temperature Tr is set to be maintained between the upper limit value Ts1 and the lower limit value Ts2 of the set temperature Ts, when the refrigerator compartment temperature Tr reaches the upper limit value Ts1, the fan motor The fan motor is turned off when it is turned on and the refrigerator compartment temperature Tr reaches the lower limit value Ts2. Moreover, when the refrigerator compartment temperature Tr reaches the set temperature Tv higher than the upper limit value Ts1, the compressor is turned on, and when the refrigerator compartment temperature Tr reaches the lower limit value Ts2, the compressor is turned off. Here, the temperature difference ΔT2 between the set temperature Tv for driving the compressor and the set temperature Ts of the refrigerating chamber is higher than the temperature difference ΔT1 between the upper limit value Ts1 and the lower limit value Ts2 of the set temperature Ts. It is preferable to set larger, and in the embodiment, the set temperature Tv is set to about 3 ° C. higher than the set temperature Ts.

Compressor operation time is integrated in the operation time integrating unit 30, the time (Ta) and the refrigerating room temperature (Ta) accumulated cumulatively the operating time of the refrigerator compartment temperature (Tr) below the set temperature (Tv), that is, in the first defrosting condition ( The time Tb in which Tr) is accumulated over the set temperature Tv, i.e., under the second defrosting condition, is cumulatively accumulated.

In the present invention, three types of defrosting operations are performed, which will be described in turn.

[Type 1] The control unit 40, when the cumulatively accumulated time (Ta = Ta1 + Ta2 + T3) reaches the set time (6 hours) under the first defrosting condition, that is, the time that satisfies the first defrosting condition. The defrost heater is turned on at (Td1), and the defrost heater is turned on, and the defrost heater is melted on the surface of the evaporator due to the heating heat. Accordingly, the defrost heater is turned off when the temperature detected by the defrost sensor reaches the defrost return temperature Te. .

[Type 2] When the time Tb accumulated cumulatively under the second defrosting condition reaches the set time (2 hours), that is, the control unit 40 defrosts the heater at the time Td3 that satisfies the second defrosting condition. Turn on the defrost heater and turn off the defrost heater when the temperature detected by the defrost sensor reaches the defrost return temperature (Te).

[Type 3] The controller 40 adds the compressor operating time Ta in the first defrosting condition and the compressor operating time Tb in the second defrosting condition, and the summed time Ta + Tb is a fixed time. When the defrost heater is turned on, in the embodiment, the defrost heater is turned on at a time Td2 at which the summed time satisfies the set time (6 hours) satisfying the first defrost condition. The defrost heater is turned on and the frost formed on the surface of the evaporator is melted due to the heating heat. Accordingly, the defrost heater is turned off when the temperature detected by the defrost sensor reaches the defrost return temperature Te.

After performing any one of the three types of defrosting operation, the compressor operation time is reset to an initial state, that is, to prevent the defrosting operation more than necessary, and after the defrosting condition is satisfied, the process of performing the defrosting operation is continued again.

Hereinafter, a control method of the refrigerator according to the present invention will be described in detail with reference to the flowchart of FIG. 3.

First, when power is applied, the controller 40 controls the compressor driver 60 to turn on the compressor (S101), and outputs a control signal to the operation time integrating unit 30 to reset the compressor first operation time Ta. (S102).

Subsequently, the controller 40 receives the refrigerating compartment temperature Tr detected through the high temperature detecting unit 20 (S103), and determines whether the refrigerating compartment temperature Tr is equal to or greater than a preset set temperature Tv (S104). ). As a result of the determination, when the refrigerating chamber temperature Tr is not higher than or equal to the preset temperature Tv, the compressor first operation time Ta is accumulated cumulatively (S105), and the accumulated first operation time Ta is a preset time. (A) For example, it is determined whether 6 hours has been reached (S106). As a result of the determination, when the accumulated first operating time Ta does not reach the set time A, the flow returns to step S103 to continuously accumulate the compressor operating time, and the integrated first operating time Ta is set. When the time A is reached, the control unit 40 controls the defrost heater driving unit 70 to turn on the defrost heater to perform a defrosting operation for removing frost formed on an evaporator for supplying cold air to the refrigerating chamber (S107). )

During the defrosting operation according to step S107, the defrost sensor 80 detects the evaporator surface temperature, that is, applies the defrost sensor temperature to the control unit 40, and the control unit 40 reaches the preset defrost return temperature. Determine whether or not (S108). As a result of the determination, when the defrosting sensor temperature does not reach the defrosting return temperature, the flow returns to step S107 to continue defrosting operation, and when the defrosting sensor temperature reaches the preset defrosting return temperature, the flow returns to the start step.

On the other hand, if the refrigerating chamber temperature Tr is equal to or greater than the preset set temperature Tv, the compressor second operation time Tb is reset (S109), and the compressor second operation time Tb is accumulated cumulatively. Integral (S110).

Subsequently, the controller 40 receives the refrigerating compartment temperature Tr detected through the high temperature detecting unit 20 (S111), and determines whether the refrigerating compartment temperature Tr is less than or equal to the set temperature Ts (S112). As a result, when the refrigerating compartment temperature Tr is less than or equal to the set temperature Ts, the flow returns to step S104. The operation time Tb is added and it is determined whether the summed operation time Ta + Tb has reached the set time A, for example, 6 hours (S113). If the determined operation time Ta + Tb reaches the set time A as a result of the determination, the process proceeds to step S107 to perform the defrosting operation, and the combined operation time Ta + Tb is set time A. If it is not reached, it is determined whether the second operation time Tb has reached a preset time B, for example, two hours (S114).

If it is determined in step S114 that the second operation time Tb does not reach the set time B, the flow returns to step S110, and when the second operation time Tb reaches the set time B, the evaporator is defrosted. The process proceeds to step S107 so as to perform defrosting operation after judging that the state of excessive conception.

As described above, according to the present invention, the defrosting operation is performed when the compressor operating time is a certain time or more in the case where the inside temperature of the refrigerating compartment is higher than a certain temperature and the inside temperature of the refrigerating compartment is higher than or equal to a predetermined time in parallel with the operation of performing the defrosting operation depending only on the compressor operating time. Even if the frost is excessively frosted on the evaporator due to frequent door opening and closing, the heat exchange efficiency between the circulating air and the evaporator can be maintained satisfactorily, and as a result, an excessive increase in the internal temperature of the refrigerator compartment is prevented. It can work. In addition, since the present invention is carried out in a range that suppresses unnecessary defrosting operation as much as possible, it is possible to effectively perform defrosting on the evaporator without wasting power consumption.

Claims (10)

In the defrost control method of the refrigerator, Set the first defrosting condition depending on the compressor operating time and the second defrosting condition depending on the internal temperature of the refrigerating chamber and the compressor operating time, and if any one of the first and second defrosting conditions is satisfied, remove the frost formed on the evaporator. Defrosting control method of a refrigerator comprising the step of performing a defrosting operation for. The method of claim 1, The defrost control method of the refrigerator, characterized in that the second defrost condition is independent of the first defrost condition. The method according to claim 1 or 2, The second defrosting condition is a defrosting control method of a refrigerator, characterized in that the compressor operation time is a predetermined time or more when the internal temperature of the refrigerating chamber is higher than the set temperature and the internal temperature of the refrigerating compartment is higher than the set temperature. The method of claim 3, And the set time is shorter than a first set time for satisfying the first defrost condition. The method of claim 3, The set temperature is higher than a first set temperature for setting a driving condition of a refrigerating fan motor, and the fan motor is turned on at the upper limit of the first set temperature and the fan motor is turned off at the lower limit of the first set temperature. Defrost control method of the refrigerator characterized in that. The method of claim 5, And a temperature difference between the set temperature and the first set temperature is greater than the temperature difference between the upper limit value and the lower limit value of the first set temperature. The method of claim 1, When the two evaporator is provided corresponding to the freezer compartment and the refrigerating compartment, the first and second defrosting conditions are defrosting control method of the refrigerator, characterized in that for the evaporator for supplying cold air to the refrigerating compartment. The method of claim 1, A first integration step of integrating the compressor operating time in the first defrosting condition and a second integration step of integrating the compressor operating time in the second defrosting condition, wherein the first and second integration steps are not dependent on each other and are separately Defrost control method of a refrigerator, characterized in that performed by. The method of claim 1, And summing the compressor operation time in the first defrosting condition and the compressor operation time in the second defrosting condition and performing defrosting operation if the combined compressor operation time is equal to or greater than a predetermined time. Defrost Control Method. The method of claim 9, The defrosting control method of the refrigerator, characterized in that the defrosting operation is performed if the summed compressor operating time is equal to or greater than a first predetermined time for satisfying the first defrosting condition.