KR20090119084A - Control device and method for defrosting of refrigerator - Google Patents

Abstract

PURPOSE: A device and a method for controlling defrosting of a refrigerator are provided to determine the amount of frost attached to an evaporator of the refrigerator using weight of the evaporator of the refrigerator which changes according to the amount of frost. CONSTITUTION: A device and a method for controlling defrosting of a refrigerator comprises a suspension unit(13b), a lever unit(13c), a piezoelectric sensor unit(13d), and a controller. The lever unit is fixed so that both ends of the lever unit move in opposite directions around a fixing point. One end of the lever unit is connected to the evaporator. Pressure is applied by the other end of the lever unit when the piezoelectric sensor unit moves. The piezoelectric sensor unit outputs an electric signal corresponding to the applied pressure. The controller determines the amount of frost attached to the evaporator using output of the piezoelectric sensor unit and controls an operation of the defrost heater according to the determination result.

Description

Control device and method for defrosting of refrigerator

The present invention relates to a defrosting control apparatus and method of the refrigerator, and more particularly, by using the weight of the refrigerator evaporator that changes according to the frost amount of the frost to determine the amount of frost formed on the refrigerator evaporator, according to the determination result The present invention relates to a defrost control apparatus and method for a refrigerator for controlling the operation of a defrost heater.

In general, a refrigerator forms a refrigeration cycle by using a compressor, a condenser, an expansion device, and an evaporator as main components, and absorbs heat inside the storage compartment by evaporation of the refrigerant flowing in the evaporator, and thus generates cold air. It is a device that keeps various foods fresh for a long time in refrigerated or frozen state by supplying it inside.

The cold air generated by the evaporation of the evaporator is circulated to the refrigerating chamber and the freezing chamber by a blower fan installed at one side of the evaporator. Will be repeated.

At this time, when the cold air circulated inside the storage compartment is in contact with the evaporator, the moisture contained in the cold air condenses or forms on the surfaces of the heat transfer tubes and the heating fins of the evaporator. In addition to inhibiting the flow rate, the flow resistance of the cold air is increased by the blower fan, which increases the power consumption of the refrigerator.

Therefore, the conventional refrigerator removes frost by periodically operating the defrost heater provided on one side of the evaporator in order to restore the original function of the evaporator when the amount of frosting is excessively increased, the defrosting method according to the prior art is described below. In detail.

On the other hand, the amount of frost that is implanted in the evaporator as described above will vary depending on various types of implantation conditions such as the type of food stored in the freezer compartment and the refrigerating compartment, the temperature and humidity of the outside air, and the frequency of opening and closing the freezer compartment and the refrigerating compartment. Since the refrigerator performs defrosting operation according to a predetermined defrosting time without considering this, it causes many problems in terms of energy efficiency.

That is, the conventional refrigerator is a method of determining the defrosting time by calculating only the cumulative operating time of the compressor in most cases, even when the evaporator is in an overset state, if the cumulative operating time is less than the reference time, the defrosting operation is not performed. As a result, the power consumption of the refrigerator is significantly increased due to the decrease in the heat transfer efficiency of the evaporator and the increase in cold flow resistance.

On the contrary, even when the amount of frosting of the evaporator is minute, when the cumulative operation time passes the reference time, the cooling operation is stopped and the defrosting operation is performed unconditionally, so that unnecessary defrost heater operation and the resulting internal temperature of the storage compartment are caused. It causes problems such as rising.

[Document 1] Republic of Korea Patent Publication No. 2007-0019153 (published Feb. 15, 2007)

The present invention is to solve the above-mentioned problems of the prior art, an object of the present invention is to determine the amount of frost actually implanted in the refrigerator evaporator by using the weight of the refrigerator evaporator that changes according to the amount of frost, and the determination result Accordingly, an object of the present invention is to provide a defrosting control apparatus and method of a refrigerator capable of accurately determining a defrosting time of the refrigerator.

In order to achieve the above object, the defrost control device of the refrigerator according to the present invention is formed in the cold air flow path is installed evaporator, suspension unit for supporting the evaporator can be moved in the vertical direction according to the weight change by the implantation, fixed It is fixed so that both ends can move in opposite directions with respect to a point, and one end is connected to the evaporator, an electrical signal is applied by the other end of the lever when the evaporator is moved and corresponds to the applied pressure. It characterized by including a piezoelectric sensor unit for outputting the output and the output of the piezoelectric sensor unit to determine the frost amount implanted in the evaporator and to control the operation of the defrost heater according to the determination result.

In addition, the cold air flow path is formed in a vertical direction, the suspension portion is characterized in that the evaporator to support the movement so as to be parallel to the cold air flow path.

The control unit may determine that the evaporator is in an over-established state when the output of the piezoelectric sensor unit is equal to or greater than a first set value, thereby operating the defrost heater.

In addition, when the output of the piezoelectric sensor is less than the second set value after the operation of the defrost heater, the controller determines that the frost formed on the evaporator has been removed and stops the operation of the defrost heater. It is characterized by being smaller than the set value.

The controller may be further configured to calculate an integrated value obtained by integrating the output of the piezoelectric sensor unit for a predetermined time, a plurality of times, and compare the average value of the integrated values with a first or second set value.

In addition, the defrosting control method of the refrigerator according to the present invention is a first for detecting the electrical signal output in response to the pressure applied from the piezoelectric sensor unit is applied by the evaporator moved in the vertical direction in accordance with the weight change caused by the idea And a second step of determining an amount of frost formed on the evaporator by using the output of the piezoelectric sensor unit and controlling an operation of a defrost heater according to the determination result, wherein the piezoelectric sensor units are opposite to each other. And pressure is applied by the other end of the lever of which one end is connected to the evaporator.

Defrost control apparatus and method of the refrigerator according to the present invention is a method of determining the amount of frost on the evaporator by using the weight of the evaporator is changed according to the amount of frost on the evaporator and controlling the defrosting operation according to the determination result. Therefore, unlike the prior art, the defrosting operation is performed only when the amount of frosting actually implanted in the evaporator has an advantage of improving the energy efficiency of the refrigerator.

Accordingly, the defrosting control apparatus and method of the refrigerator according to the present invention can solve the problem of the related art by applying the defrosting condition to the defrosting operation control so that unnecessary defrosting operation or actual defrosting operation is not performed during the operation of the refrigerator. have.

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

1 is a longitudinal sectional view showing a refrigerator equipped with a defrosting control apparatus according to an embodiment of the present invention. The refrigerator 1 of FIG. 1 rotates the main body 5 in which the freezer compartment 3 and the refrigerating compartment 4 are formed, and the freezer compartment 3 and the refrigerating compartment 4, respectively, with partitions 2 interposed therebetween in the vertical direction. It has a freezing chamber door 6 and the refrigerating chamber door 7 which is hinged to the main body so as to be able to.

In addition, in the rear region of the freezing chamber 3, the shroud member 9 is provided at a predetermined distance from the inner wall of the main body 5 so as to form the cold air flow path 8, and one side of the shroud member 9 is provided. The grill member 11 formed with the air discharge port 10 is installed spaced apart.

In addition, freezer compartment return passages 12a are formed in both regions of the partition wall 2 so that cold air in the freezer compartment 3 can return to the cold air passage 8, and cold air passages in the refrigerating compartment 4 are formed in the central region. The refrigerating chamber return flow path 12b is formed so that it may return to (8).

In addition, in the cold air flow passage 8 formed in the rear region of the freezing chamber 3, an evaporator unit 13 is installed to allow heat exchange of cold air introduced into the cold air flow passage 8 through the return passages 12a and 12b. The upper side of the evaporator unit 13 is provided with a blower fan 14 so that the cold air passing through the evaporator unit 13 may be provided to the freezing chamber 3 or the refrigerating chamber 4.

In addition, one side of the evaporator unit 13 is provided with a defrost heater 20 for heating and removing frost formed on the surface of the evaporator unit 13.

Meanwhile, the compressor 30 is installed in the lower rear region of the main body 5 so as to receive and compress the refrigerant from the evaporator unit 13, and one side of the compressor 30 is refrigerant compressed by the compressor 30. A condenser (not shown) for receiving and condensing through heat radiation is provided.

When the blower fan 14 is operated in the refrigerator 1 having the above configuration, the cool air in the freezer compartment 3 and the refrigerating compartment 4 flows into the lower side of the evaporator unit 13 through the return passages 12a and 12b. And heat exchanged with the relatively low temperature refrigerant while passing through the evaporator unit 13 to the freezing chamber 3 or the refrigerating chamber 4.

2A and 2B are schematic diagrams showing the structure and operation principle of the defrosting control device according to an embodiment of the present invention before and after implantation into the evaporator unit 13, respectively, according to the present embodiment. Suspension is coupled to the evaporator (13a) installed in the middle of the cold air flow path (8) formed vertically, the cold air flow path (8) and the suspension to support the evaporator (13a) to move in the vertical direction in accordance with the weight change caused by the implantation (13b) is applied by a lever 13c fixed at both ends about a fixed point so as to be moved in opposite directions to each other, and one end connected to the evaporator, and the other end of the lever when the evaporator 13a is moved. It comprises a piezoelectric sensor 13d for outputting an electrical signal corresponding to the losing pressure.

The suspension 13b is an elastic support for supporting the evaporator 13a to be moved up and down in the cold air flow path 8 according to the weight change, and may be preferably implemented by a spring or the like.

At this time, in order to accurately detect the weight change of the evaporator (13a), the suspension (13b) is coupled to the plane center or left and right symmetry point of one side of the evaporator (13a) so that the evaporator (13a) parallel to the cold air flow path (8). It is desirable to be able to move.

As shown in Fig. 2A, if frost is not implanted in the evaporator 13a, the evaporator 13a is positioned at a point where gravity and suspension tension are in equilibrium, in which case it is not connected to the evaporator 13a. Since the other end of the lever 13c does not compress the piezoelectric sensor 13d, the piezoelectric sensor 13d outputs an electrical signal (for example, a voltage signal) V1 having a predetermined size.

However, as time passes, the evaporator 13a starts to be implanted, and as shown in FIG. 2B, the weight of the evaporator 13a is increased by the weight of the frost 13f formed on the surface of the evaporator 13a. As a result, the evaporator 13a moves downward until gravity acting on the evaporator 13a is again in equilibrium with the tension of the suspension.

At this time, the other end of the lever 13c not connected to the evaporator 13a moves in the opposite direction to the moving direction of the evaporator 13a to compress the piezoelectric sensor 13d, and the piezoelectric sensor 13d is proportional to the compressive force. As a result, the electric signal V2 having a magnitude higher than that described above is output.

Therefore, the defrost control device of the refrigerator 1 according to the present invention can detect the output of the piezoelectric sensor 13d to determine the weight change of the evaporator 13a, that is, the amount of frost formed on the evaporator 13a.

Figure 3 is a block diagram showing the configuration of a defrost control device according to an embodiment of the present invention.

When the refrigerator 1 according to the present embodiment starts cooling operation and frost begins to form on the evaporator 13a, the controller 100 integrates and averages the output value received from the piezoelectric sensor 13d as described below. By comparing the preset value stored in the memory 130, and determines the state of the evaporator (13a) in accordance with the comparison result to control the operation of the defrost heater (20).

At this time, since the configuration and operation principle of the piezoelectric element is a known technique, a detailed description thereof will be omitted.

4 is a flowchart illustrating a control method of a defrost control apparatus according to an embodiment of the present invention.

When power is supplied to the refrigerator 1 and the refrigerator 1 performs a cooling operation (S110), the controller 100 performs a process of integrating the output value of the piezoelectric sensor 13d for a predetermined time a plurality of times (S120). .

When the step S120 is completed, the control unit 100 determines whether the average value of the integrated output values is greater than or equal to a first preset value stored in the memory 110 (S130). do.

On the other hand, when the determination result of step S130 is greater than the first set value, the control unit 100 determines that the evaporator 13a is in an over-melting state and performs a defrosting operation to operate the defrost heater 20 (S140).

When the step S140 is completed, the control unit 100 performs a process of integrating the output value of the piezoelectric sensor 13d for a predetermined time a plurality of times (S150).

When the step S150 is completed, the control unit 100 determines whether the average value of the integrated output values is less than the second preset value previously stored in the memory 110 (S160). do.

On the other hand, when the determination result of step S160 is less than the second set value, the control unit 100 determines that the frost (13f) implanted in the evaporator (13a) is removed to stop the operation of the defrost heater (20).

When the step S170 is completed, the control unit 100 determines whether a control signal for terminating the operation of the refrigerator 1 has been input (S180), and if so, terminates the control and if not, performs the step S110. The cooling operation is performed again.

The first set value and the second set value are experimentally obtained in advance and stored in the memory 110, and the first set value corresponds to the case where the evaporator 13a is in an overset state. It is preferable to set to the value which integrated the output value.

In addition, it is preferable that the second set value is set to a value obtained by integrating the output value of the piezoelectric sensor 13d with respect to the case where the evaporator 13a is not in an over-phase state, in order to prevent the defrosting operation from being performed unnecessarily frequently. It is preferable to set smaller than a 1st set value.

1 is a longitudinal sectional view showing a refrigerator equipped with a defrost control device according to an embodiment of the present invention;

2A and 2B are schematic diagrams showing the configuration and operation principle of a defrosting control device according to an embodiment of the present invention before and after implantation into an evaporator, respectively;

3 is a block diagram showing a configuration of a defrosting control apparatus according to an embodiment of the present invention; and

4 is a flowchart illustrating a control method of a defrost control apparatus according to an embodiment of the present invention.

Claims (9)

A suspension part formed in a cold air flow path provided with an evaporator and supporting the evaporator in a vertical direction according to a weight change due to implantation; A lever unit which is fixed so that both ends are moved in opposite directions with respect to a fixed point, and one end is connected to the evaporator; A piezoelectric sensor unit which is pressurized by the other end of the lever portion when the evaporator moves and outputs an electrical signal corresponding to the applied pressure; And And a controller configured to determine an amount of frost formed on the evaporator by using the output of the piezoelectric sensor and to control an operation of the defrost heater according to the determination result. The method of claim 1, The cold air flow path is formed in the vertical direction, The suspension control unit of the refrigerator, characterized in that for supporting the evaporator to be moved in parallel to the cold air flow path. The method of claim 2, And the control unit determines that the evaporator is in an overset state when the output of the piezoelectric sensor unit is equal to or greater than a first set value, and operates the defrost heater. The method of claim 3, When the output of the piezoelectric sensor unit is less than the second set value after the operation of the defrost heater determines that the frost formed on the evaporator is removed, the operation of the defrost heater is stopped, And the second set value is smaller than the first set value. The method of claim 4, wherein And the control unit calculates an integrated value obtained by integrating the output of the piezoelectric sensor unit for a predetermined time, a plurality of times, and compares an average value of the integrated values with a first set value or a second set value. A first step of detecting an electrical signal output in response to the applied pressure from a piezoelectric sensor unit to which pressure is applied by an evaporator which is moved up and down in accordance with weight change due to an implantation; and A second step of determining the frost amount implanted in the evaporator by using the output of the piezoelectric sensor unit, and controlling the operation of the defrost heater according to the determination result, The piezoelectric sensor unit, the defrost control method of the refrigerator, characterized in that the pressure is applied by the other end of the lever of the both ends are moved in the opposite direction and the one end is connected to the evaporator. The method of claim 6, And the second step includes a third step of operating the defrost heater by determining that the evaporator is in an overset state when the output of the piezoelectric sensor is equal to or greater than a first set value. The method of claim 7, wherein The second step is a fourth step of detecting the output of the piezoelectric sensor unit after the operation of the defrost heater; And If the output of the piezoelectric sensor unit detected in the fourth step is less than the second set value further comprises a fifth step of stopping the operation of the defrost heater by determining that the frost formed on the evaporator has been removed, And the second set value is smaller than the first set value. The method of claim 8, In the third and fifth steps, an integrated value obtained by integrating the outputs of the piezoelectric sensor units sensed in the first and fourth steps, respectively, for a set time is calculated a plurality of times, and the average value of the integrated values is calculated as a first set value. Or the defrost control method of the refrigerator, characterized in that compared with the second set value.

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