CN114704994B

CN114704994B - Refrigerator with a refrigerator body

Info

Publication number: CN114704994B
Application number: CN202210356346.XA
Authority: CN
Inventors: 崔相福; 金成昱; 朴景培; 池成
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2018-03-08
Filing date: 2019-01-31
Publication date: 2023-12-29
Anticipated expiration: 2039-01-31
Also published as: EP3764033A1; AU2019232055A1; CN114704994A; AU2019232055B2; US20210055034A1; CN111801539A; EP3764033A4; KR102614564B1; WO2019172532A1; KR20190106242A; CN111801539B

Abstract

The invention provides a refrigerator. A method of controlling a refrigerator according to an embodiment of the present invention, the method comprising the steps of: the heating element of the sensor responsive to the air flow rate change is turned on for a predetermined period of time and then turned off; sensing a first sensed temperature (Ht 1) of the heating element in a state in which the heating element is turned on, and sensing a second sensed temperature (Ht 2) of the heating element in a state in which the heating element is turned off; and sensing an amount of frost on the evaporator based on a temperature difference between the first sensed temperature (Ht 1) and the second sensed temperature (Ht 2).

Description

Refrigerator with a refrigerator body

The present application is a divisional application of the invention patent application (International application No. PCT/KR2019/001340, application date: 2019, 01, 31, title of the invention: refrigerator and control method thereof) of the original application No. 201980016711.9.

Technical Field

The present disclosure relates to a refrigerator and a control method thereof.

Background

A refrigerator is a home appliance capable of storing articles such as food at a low temperature in a storage chamber provided in a cabinet. Since the storage space is surrounded by the heat insulating wall, the inside of the storage space can be maintained at a temperature less than the outside temperature.

The storage space may be classified as a refrigerated storage space or a frozen storage space according to the temperature range of the storage space.

The refrigerator may further include an evaporator for supplying cool air to the storage space. The air in the storage space is cooled while flowing to the space where the evaporator is disposed, thereby exchanging heat with the evaporator, and the cooled air is supplied to the storage space again.

Here, if the air heat-exchanged with the evaporator contains moisture, the moisture freezes on the surface of the evaporator when the air heat-exchanged with the evaporator, thereby generating frost on the surface of the evaporator.

Since the flow resistance of air acts on the frost, the more the amount of frost frozen on the evaporator surface increases, the more the flow resistance increases. As a result, the heat exchange efficiency of the evaporator may be deteriorated, and thus power consumption may be increased.

Accordingly, the refrigerator further includes a defroster for removing frost on the evaporator.

Korean patent laid-open No. 2000-0004806 (prior art document) discloses a defrosting cycle variable method.

In the prior art document, the cumulative operation time of the compressor and the external temperature are utilized to adjust the defrost cycle.

However, as in the prior art document, when the defrosting cycle is determined using only the accumulated operation time of the compressor and the external temperature, the amount of frost on the evaporator (hereinafter referred to as frost generation amount) is not reflected. Therefore, it is difficult to accurately determine the point in time when defrosting is required.

That is, the frost generation amount may be increased or decreased according to various environments such as a refrigerator usage pattern of a user and a degree to which air keeps moisture. In the case of the prior art document, there is a disadvantage in that the defrost cycle is determined without reflecting various environments.

Further, in the case of the prior art document, there is a disadvantage in that it is difficult to detect the amount of frost on the entire evaporator because the partial amount of frost of the evaporator can be detected, and thus it is difficult to identify an exact defrosting time point.

Thus, there are disadvantages in that: although a large amount of frost is generated and defrosting is not started, thereby deteriorating cooling performance; or the defrosting starts although the amount of frost generated is low, thereby increasing power consumption due to unnecessary defrosting.

Disclosure of Invention

Technical problem

An object of the present disclosure is to provide a refrigerator and a control method thereof, which determine a time point for a defrosting operation using a parameter that is changed depending on an amount of frost on an evaporator.

Further, it is an object of the present disclosure to provide a refrigerator and a control method thereof that accurately determines a time point when defrosting is required according to an amount of frost on an evaporator using a sensor having an output value that is changed depending on an air flow rate.

Further, it is another object of the present disclosure to provide a refrigerator and a control method thereof, which can accurately determine a time point of defrosting even in the case where the accuracy of a sensor for determining the time point of defrosting is low.

Further, it is still another object of the present disclosure to provide a refrigerator and a control method thereof, in which a detection logic for detecting an amount of frost on an evaporator may be performed at an appropriate point of time.

Further, it is still another object of the present disclosure to provide a refrigerator and a control method thereof, which improve reliability in consideration of a change in external environment in detecting an amount of frost on an evaporator.

Technical proposal

In order to solve the above-described problems, a control method of a refrigerator includes detecting an amount of frost on an evaporator based on a temperature difference between a first detection temperature (Ht 1) of a heating element of a sensor detected in a state in which the heating element is turned on and a second detection temperature (Ht 2) of the heating element detected in a state in which the heating element is turned off, the sensor being responsive to a change in an air flow rate.

As an example, the first detected temperature (Ht 1) may be a temperature detected by a sensing element of the sensor immediately after the heating element is turned on, and the second detected temperature (Ht 2) may be a temperature detected by a sensing element of the sensor immediately after the heating element is turned off.

As an example, the first detected temperature (Ht 1) may be a lowest temperature value within a period in which the heating element is turned on, and the second detected temperature (Ht 2) is a highest temperature value after the heating element is turned off.

Further, the heating element may be in an open state when the storage compartment of the refrigerator is being cooled. As an example, the heating element may be in an open state while driving the blower for cooling the storage chamber.

The control method of the present disclosure may further include: determining whether a temperature difference between the first detected temperature (Ht 1) and the second detected temperature (Ht 2) is less than a first reference difference; and performing a defrosting operation of removing frost generated on a surface of the evaporator when it is determined that a temperature difference between the first detected temperature (Ht 1) and the second detected temperature (Ht 2) is less than a first reference difference.

The control method of the present disclosure may further include: when the heating element is turned on for the predetermined period of time and then turned off, it is determined whether a temperature difference between the first detected temperature (Ht 1) and the second detected temperature (Ht 2) is less than a second reference difference value, and the heating element may be turned on when the temperature difference between the first detected temperature (Ht 1) and the second detected temperature (Ht 2) is less than the second reference difference value.

When the temperature difference between the first detected temperature (Ht 1) and the second detected temperature (Ht 2) is smaller than the second reference difference value, the heating element is turned on based on the accumulated cooling operation time of the storage chamber.

In order to solve the above problems, a method of controlling a refrigerator includes: the amount of frost on the evaporator is detected based on a temperature difference between a first detection temperature (Ht 1) as a lowest value and a second detection temperature (Ht 2) as a highest value among the detection temperatures of the heating element.

Further, the heating element may be in an open state when the storage compartment of the refrigerator is being cooled. As an example, the heating element may be in an on state while driving the fan for cooling the storage chamber.

The control method of the refrigerator may further include: determining whether a temperature difference between the first detected temperature (Ht 1) and a second detected temperature (Ht 2) is less than a first reference difference; and performing a defrosting operation of removing frost generated on a surface of the evaporator when it is determined that a temperature difference between the first detected temperature (Ht 1) and the second detected temperature (Ht 2) is less than a first reference difference.

In order to solve the above problems, a refrigerator may include: a heating element; a sensor including a sensing element that detects a temperature of the heating element; and a controller that detects an amount of frost on the evaporator based on a temperature difference between a first detected temperature (Ht 1) of the heating element detected in a state where the heating element is turned on and a second detected temperature (Ht 2) of the heating element detected in a state where the heating element is turned off.

Advantageous effects

According to the proposed invention, since the time point at which defrosting is required is determined using the sensor having the output value that is changed according to the amount of frost generated on the evaporator in the bypass passage, the time point at which defrosting is required can be accurately determined.

Further, even in the case where the accuracy of the sensor for determining the defrosting time point is low, the time point of defrosting can be accurately determined, thereby significantly reducing the cost of the sensor.

Further, since the detection logic for detecting the amount of frost on the evaporator can be performed at an appropriate point in time, power consumption is reduced and convenience is improved.

Further, since a change in external environment (e.g., an internal refrigerator load) is taken into consideration in detecting the amount of frost on the evaporator, product reliability is improved.

Drawings

Fig. 1 is a schematic longitudinal cross-sectional view of a refrigerator according to an embodiment of the present invention.

Fig. 2 is a perspective view of a cool air duct according to an embodiment of the present invention.

Fig. 3 is an exploded perspective view showing a state in which a channel cover and a sensor are separated from each other in a cool air duct.

Fig. 4 is a view showing the flow of air in the heat exchange space and the bypass passage before and after frost is generated.

Fig. 5 is a schematic diagram showing a state in which the sensor is arranged in the bypass passage.

Fig. 6 is a view of a sensor according to one embodiment of the invention.

Fig. 7 is a view showing heat flow around the sensor depending on the air flow through the bypass passage.

Fig. 8 is a control block diagram of a refrigerator according to an embodiment of the present disclosure.

Fig. 9 is a flowchart illustrating a control method for detecting an amount of frost on an evaporator according to an embodiment of the present disclosure.

Fig. 10 is a flowchart illustrating a method of performing a defrosting operation by determining a point in time when a refrigerator needs to be defrosted according to one embodiment of the present disclosure.

Fig. 11 is a view showing a temperature change of a heating element according to the opening/closing of the heating element before and after frosting on an evaporator according to one embodiment of the present disclosure.

Fig. 12 is a flowchart illustrating a control method for determining an operating time point of a heating element according to one embodiment of the present disclosure.

Detailed Description

Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Note that even if the same or similar components in the drawings are shown in different drawings, the same reference numerals are used as far as possible to designate the components. Further, in the description of the embodiments of the present disclosure, when it is determined that detailed description of well-known configurations or functions interferes with understanding of the embodiments of the present disclosure, the detailed description will be omitted.

Further, in the description of the embodiments of the present disclosure, terms such as first, second, A, B, (a) and (b) may be used. Each term is used merely to distinguish a corresponding component from other components and does not limit the nature, order or sequence of the corresponding components. It will be understood that when an element is "connected," "coupled," or "joined" to another element, the former may be directly connected or joined to the latter, or may be "connected," "coupled," or "joined" to another element with a third element interposed therebetween.

Fig. 1 is a schematic longitudinal sectional view of a refrigerator according to an embodiment of the present invention, fig. 2 is a perspective view of a cool air duct according to an embodiment of the present invention, and fig. 3 is an exploded perspective view showing a state in which a duct cover and a sensor are separated from each other in the cool air duct.

Referring to fig. 1 to 3, a refrigerator 1 according to an embodiment of the present invention may include an inner case 12 defining a storage space 11.

The storage space may include one or more of a refrigerated storage space and a frozen storage space.

The cool air duct 20 provides a passage in the rear space of the storage space 11 through which cool air supplied to the storage space 11 flows. Further, the evaporator 30 is arranged between the cool air duct 20 and the rear wall 13 of the inner case 12. That is, a heat exchange space 222 in which the evaporator 30 is disposed is defined between the cool air duct 20 and the rear wall 13.

Accordingly, the air of the storage space 11 may flow to the heat exchange space 222 between the cool air duct 20 and the rear wall 13 of the inner case 12, and then heat-exchange with the evaporator 30. Thereafter, air may flow through the inside of the cool air duct 20 and then be supplied to the storage space 11.

The cool air duct 20 may include, but is not limited to, a first duct 210 and a second duct 220, the second duct 220 being coupled to a rear surface of the first duct 210.

The front surface of the first duct 210 is a surface facing the storage space 11, and the rear surface of the first duct 210 is a surface facing the rear wall 13 of the inner case 12.

In a state where the first duct 210 and the second duct 220 are coupled to each other, a cool air passage 212 may be provided between the first duct 210 and the second duct 220.

Further, the second duct 220 may have a cool air inflow hole 221 defined therein, and the first duct 210 may have a cool air discharge hole 211 defined therein.

A blower (not shown) may be provided in the cool air passage 212. Accordingly, when the blower fan rotates, air passing through the evaporator 30 is introduced into the cold air passage 212 via the cold air inflow hole 221 and discharged to the storage space 11 via the cold air discharge hole 211.

The evaporator 30 is arranged between the cold air duct 20 and the rear wall 13. Here, the evaporator 30 may be disposed under the cool air inflow hole 221.

Accordingly, the air in the storage space 11 rises to exchange heat with the evaporator 30, and is then introduced into the cool air inflow hole 221.

According to this arrangement, when the amount of frost generated on the evaporator 30 increases, the amount of air passing through the evaporator 30 may be reduced, thereby deteriorating heat exchange efficiency.

In this embodiment, a time point at which defrosting of the evaporator 30 is required may be determined using a parameter that varies according to the amount of frost generated on the evaporator 30.

For example, the cool air duct 20 may further include a frost generation sensing portion configured to bypass at least a portion of the air flowing through the heat exchange space 222 and to determine a point of time at which defrosting is required by using a sensor having a different output according to the air flow rate.

The frost generation sensing portion may include: a bypass passage 230 that bypasses at least a portion of the air flowing through the heat exchange space 222; and a sensor 270 disposed in bypass passage 230.

Although not limited, the bypass passage 230 may be provided in the first duct 210 in a recessed shape. Alternatively, bypass passage 230 may be provided in second conduit 220.

Bypass passage 230 may be provided by recessing a portion of first conduit 210 or second conduit 220 in a direction away from evaporator 30.

The bypass passage 230 may extend in a vertical direction from the cool air duct 20.

The bypass passage 230 may be disposed to face the evaporator 30 in a left-right width range of the evaporator 30 such that air in the heat exchange space 222 is bypassed to the bypass passage 230.

The frost generation sensing portion may further include a passage cover 260, the passage cover 260 allowing the bypass passage 230 to be separated from the heat exchange space 222.

A channel cover 260 may be coupled to the cool air duct 20 to cover at least a portion of the vertically extending bypass channel 230.

The channel cover 260 may include: a cover plate 261; an upper extension 262 extending upward from the cover plate 261; and a blocking portion 263 disposed under the cover plate 261.

Fig. 4 (a) shows the flow of air before frost is generated, and fig. 4 (b) shows the flow of air after frost is generated. In the present embodiment, as an example, a state after the defrosting operation is completed is assumed as a state before frost is generated.

First, referring to fig. 4 (a), in the case where there is no frost on the evaporator 30 or the amount of frost generated is very small, most of the air passes through the evaporator 30 in the heat exchange space 222 (see arrow a). On the other hand, some air may flow through bypass passage 230 (see arrow B).

Referring to fig. 4 (b), when the amount of frost generated on the evaporator 30 is large (when defrosting is required), the amount of air flowing through the heat exchange space 222 may be reduced (see arrow C) and the amount of air flowing through the bypass passage 230 may be increased (see arrow D) because the frost of the evaporator 30 acts as a flow resistance.

As described above, the amount (or flow rate) of air flowing through the bypass passage 230 is changed according to the amount of frost generated on the evaporator 30.

In this embodiment, the sensor 270 may have an output value that varies according to a change in the flow rate of air flowing through the bypass passage 230. Therefore, it is possible to determine whether defrosting is required based on the change in the output value.

Hereinafter, the structure and principle of the sensor 270 will be described.

Fig. 5 is a schematic view showing a state in which a sensor is arranged in a bypass passage, fig. 6 is a view of the sensor according to an embodiment of the present invention, and fig. 7 is a view showing heat flow around the sensor depending on an air flow flowing through the bypass passage.

Referring to fig. 5-7, sensor 270 may be disposed at a point in bypass passage 230. Accordingly, sensor 270 may contact air flowing along bypass passage 230, and the output value of sensor 270 may vary in response to changes in air flow.

The sensor 270 may be disposed at a location spaced apart from each of the inlet 231 and the outlet 232 of the bypass passage 230. For example, sensor 270 may be located in a central portion of bypass passage 230.

Because the sensor 270 is disposed on the bypass passage 230, the sensor 270 may face the evaporator 30 within the left-right width of the evaporator 30.

The sensor 270 may be, for example, a temperature sensor that generates heat. In particular, the sensor 270 may include a sensor PCB 271, a heating element 273 mounted on the sensor PCB 271, and a sensing element 274 mounted on the sensor PCB 271 to sense a temperature of the heating element 273.

The heating element 273 may be a resistor that generates heat when a current is applied.

The sensing element 274 may sense the temperature of the heating element 273.

When the flow rate of the air flowing through the bypass passage 230 is low, the temperature sensed by the sensing element 274 is high because the cooling amount of the heating element 273 by the air is small.

On the other hand, if the flow rate of the air flowing through the bypass passage 230 is large, the temperature sensed by the sensing element 274 decreases because the cooling amount of the heating element 273 by the air flowing through the bypass passage 230 increases.

The sensor PCB 271 may determine a difference between the temperature sensed by the sensing element 274 in a state where the heating element 273 is turned off and the temperature sensed by the sensing element 274 in a state where the heating element 273 is turned on.

The sensor PCB 271 may determine whether the difference between the on/off states of the heating element 273 is smaller than the reference difference.

For example, referring to fig. 4 and 7, when the amount of frost generated on the evaporator 30 is small, the flow rate of air flowing to the bypass passage 230 is small. In this case, the heat flow of the heat generating element 273 is small, and the amount by which the heat generating element 273 is cooled by air is small.

On the other hand, when the amount of frost generated on the evaporator 30 is large, the flow rate of air flowing to the bypass passage 230 is large. Then, the heat flow and cooling amount of the heating element 273 are large by the air flowing along the bypass passage 230.

Therefore, the temperature sensed by the sensing element 274 when the amount of frost generated on the evaporator 30 is large is smaller than the temperature sensed by the sensing element 274 when the amount of frost generated on the evaporator 30 is small.

Therefore, in the present embodiment, when the difference between the temperature sensed by the sensing element 274 in the state where the heating element 273 is turned on and the temperature sensed by the sensing element 274 in the state where the heating element 273 is turned off is smaller than the reference temperature difference, it may be determined that defrosting is required.

According to this embodiment, the sensor 270 may sense a change in temperature of the heating element 273, the temperature of the heating element 273 being changed according to the flow rate of air changed according to the amount of frost generated to accurately determine the point in time when defrosting is required according to the amount of frost generated on the evaporator 30.

The sensor 270 may also be provided with a sensor housing 272 such that air flowing through the bypass channel 230 is prevented from directly contacting the sensor PCB 271, the heating element 273 and the sensing element 274. In a state where the sensor housing 272 is opened at one side, the electric wire connected to the sensor PCB 271 may be drawn out, and then the opened portion may be covered with the cover.

The sensor housing 272 may surround the sensor PCB 271, the heating element 273, and the sensing element 274.

Referring to fig. 8, a refrigerator 1 according to an embodiment of the present disclosure may include: the sensor 270; a defrosting device 50 operated to defrost the evaporator 30; a compressor 60 for compressing a refrigerant; a blower 70 for generating an air flow; and a controller 40 for controlling the sensor 270, the defroster 50, the compressor 60, and the blower 70.

The defrosting device 50 may include, for example, a heater. When the heater is turned on, heat generated by the heater is transferred to the evaporator 30 to melt frost generated on the surface of the evaporator 30. The heater may be connected to one side of the evaporator 30, or may be disposed to be spaced apart from a position adjacent to the evaporator 30.

The compressor 60 is a device for compressing a low-temperature low-pressure refrigerant into a high-temperature high-pressure supersaturated gaseous refrigerant. Specifically, the high-temperature and high-pressure supersaturated gaseous refrigerant compressed in the compressor 60 flows into a condenser (not shown). The refrigerant is condensed into a high-temperature high-pressure saturated liquid refrigerant, and the condensed high-temperature high-pressure saturated liquid refrigerant is introduced into an expander (not shown) and expanded into a low-temperature low-pressure two-phase refrigerant.

In addition, the low-temperature low-pressure two-phase refrigerant is evaporated into a low-temperature low-pressure gaseous refrigerant while passing through the evaporator 30. In this process, the refrigerant flowing through the evaporator 30 may exchange heat with the outside air (i.e., the air flowing through the heat exchange space 222), thereby achieving air cooling.

The blower 70 is disposed in the cool air passage 212 to generate an air flow. Specifically, when the blower 70 rotates, the air passing through the evaporator 30 flows into the cold air passage 212 via the cold air inflow hole 221, and is then discharged to the storage space 11 via the cold air discharge hole 211.

The controller 40 may control the heating element 273 of the sensor 270 to be turned on at regular intervals.

To determine when defrost is required, the heating element 273 may be maintained in an open state for a predetermined period of time and the temperature of the heating element 273 may be detected by the sensing element 274.

After the heating element 273 is turned on for a predetermined period of time, the heating element 273 is turned off, and the sensing element 274 may detect the temperature of the turned-off heating element 273. In addition, the sensor PCB 271 may determine whether the maximum value of the temperature difference between the on/off states of the heating element 273 is equal to or less than the reference difference value.

Further, when the maximum value of the temperature difference between the on/off states of the heating element 273 is equal to or less than the reference difference value, it is determined that defrosting is required, and the controller 40 may turn on the defrosting device 50.

Although it has been described above that the sensor PCB 271 determines whether the temperature difference between the on/off states of the heating element 273 is equal to or less than the reference difference, the controller 40 may alternatively determine whether the temperature difference between the on/off states of the heating element 273 is equal to or less than the reference difference and control the defrosting device 50 according to the determination result. That is, the sensor PCB 271 and the controller 40 may be electrically connected to each other.

Hereinafter, a method for detecting the amount of frost on the evaporator 30 using the heating element 273 will be described in detail with reference to the accompanying drawings.

Fig. 9 is a flowchart illustrating a control method for detecting an amount of frost on an evaporator according to an embodiment of the present disclosure. In the present embodiment, a method for detecting the amount of frost on the evaporator 30 in a state where the storage space 11 (e.g., the freezing chamber) is subjected to a cooling operation.

Referring to fig. 9, in step S11, the heating element 273 is turned on.

Specifically, the heating element 273 may be turned on in a state in which a cooling operation of the storage space 11 (e.g., the freezing chamber) is performed.

Here, the state in which the cooling operation of the freezing chamber is performed may refer to a state in which the compressor 60 and the blower 70 are driven.

As described above, when the change in the flow rate of air increases with the size of the amount of frost on the evaporator 30, the detection accuracy of the sensor 270 can be improved. That is, when the variation in the flow rate of air is large with the amount of frost on the evaporator 30, the variation in the temperature detected by the sensor 270 becomes large, and thus at a point in time at which defrosting is required can be accurately determined.

Therefore, the accuracy of the sensor can be improved only when detecting frost on the evaporator 30 in a state where air flow occurs (i.e., in a case where the blower fan 70 is driven).

Next, in step S13, when the heating element 273 is turned on, the temperature of the heating element 273 is detected.

Specifically, the heating element 273 may be turned on for a predetermined period of time, and the temperature (Ht 1) of the heating element 273 may be detected by the sensing element at a specific point of time in a state where the heating element 273 is turned on.

As the period of turning on the heating element 273 increases, the temperature of the heating element 273 may gradually increase. Further, the temperature of the heating element 273 may gradually rise and converge to the highest temperature point.

On the other hand, when the amount of frost on the evaporator 30 is large, the flow rate of air flowing into the bypass passage 230 increases, and thus the cooling amount of the heating element 273 by the air flowing through the bypass passage 230 increases. Then, the highest temperature point of the heat generating element 273 can be set to be low by the air flowing through the bypass passage 230.

On the other hand, when the amount of frost on the evaporator 30 is small, the flow rate of air flowing into the bypass passage 230 decreases, and therefore, the cooling amount of the heating element 273 by the air flowing through the bypass passage 230 decreases. Then, the highest temperature point of the heat generating element 273 can be set higher by the air flowing through the bypass passage 230.

In the present embodiment, the temperature of the heating element 273 can be detected at the point of time when the heating element 273 is turned on. That is, in the present disclosure, it is understood that the lowest temperature value of the heat generating element 273 is detected after the heat generating element 273 is turned on.

Next, in step S15, after a predetermined period of time has elapsed, the heating element 273 is turned off.

As an example, the heating element 273 may be maintained in an open state for three minutes and then turned off.

When the heating element 273 is turned off, the temperature of the heating element 273 may be rapidly lowered due to the air flowing through the bypass passage 230.

As the period in which the heating element 273 is turned off increases, the temperature of the heating element 273 may rapidly decrease. In addition, the temperature of the heating element 273 may be rapidly decreased and then gradually decreased from a specific point in time.

Next, in step S17, the temperature of the heating element 273 is detected in a state where the heating element 273 is turned off.

Specifically, the temperature of the heating element 273 may be detected at a specific point in time in a state where the heating element 273 is turned off.

In the present embodiment, the temperature of the heating element 273 can be detected at the point of time when the heating element 273 is turned off. That is, in the present disclosure, it is understood that the highest temperature value of the heat generating element 273 is detected after the heat generating element 273 is turned off.

Next, in step S19, the amount of frost on the evaporator 30 may be determined based on a temperature difference between the temperature detected in the state where the heating element 273 is turned on and the temperature detected in the state where the heating element 273 is turned off.

As described above, when the amount of frost on the evaporator 30 is large, the flow rate of air flowing into the bypass passage 230 increases, and thus, the cooling amount of the heating element 273 by the air flowing through the bypass passage 230 increases. Then, the detected highest temperature value of the heating element 273 becomes small, and as a result, the temperature difference between the lowest temperature value and the highest temperature value of the heating element 273 may become large.

In contrast, when the amount of frost on the evaporator 30 is small, the flow rate of air flowing into the bypass passage 230 decreases, and thus, the cooling amount of the heating element 273 by the air flowing through the bypass passage 230 decreases. Then, the detected highest temperature value of the heating element 273 becomes large, and as a result, the temperature difference between the lowest temperature value and the highest temperature value of the heating element 273 may become small.

As described above, by detecting the minimum temperature value and the maximum temperature value when the heating element 273 is turned on/off, the cooling amount of the heating element 273 can be accurately determined by the air flowing through the bypass passage 230.

In summary, when the temperature difference between the lowest temperature value and the highest temperature value of the heating element 273 is equal to or smaller than the reference value, it can be determined that the amount of frost on the evaporator 30 is large. In addition, when it is determined that the amount of frost on the evaporator 30 is large, a defrosting operation may be performed.

Hereinafter, a detailed method for detecting the amount of frost on the evaporator 30 described above will be described in detail with reference to the accompanying drawings.

Fig. 10 is a flowchart illustrating a method of performing a defrosting operation by determining a point in time when a refrigerator needs to be defrosted according to one embodiment of the present disclosure, and fig. 11 is a view illustrating a temperature change of a heating element according to opening/closing of the heating element before and after frosting on an evaporator according to one embodiment of the present disclosure.

Fig. 11 (a) shows a temperature change of the freezing chamber and a temperature change of the heating element before frost appears on the evaporator 30, and fig. 11 (b) shows a temperature change of the freezing chamber and a temperature change of the heating element after frost appears on the evaporator 30. In the present embodiment, it is assumed that the state before the occurrence of frost is the state after the defrosting operation is completed.

Referring to fig. 10 and 11, in step S21, the heat generating element 273 is turned on.

Specifically, the heating element 273 may be turned on in a state where a cooling operation is performed on the storage space 11 (e.g., the freezing chamber).

As an example, as shown in fig. 11, in the case where the blower 70 is driven, the heating element 273 may be turned on at a specific point of time S1.

The blower 70 may be driven for a predetermined period of time to cool the freezing chamber. In this case, the compressors 60 may be driven simultaneously. Therefore, when the blower 70 is driven, the temperature Ft of the freezing chamber may be lowered.

On the other hand, when the heating element 273 is turned on, the temperature detected by the sensing element 274 (i.e., the temperature Ht of the heating element 273) may be rapidly increased.

Next, in step S22, it may be determined whether the blower 70 is turned on.

As described above, the sensor 270 can detect the temperature change of the heating element 273 due to the air whose flow rate is changed according to the amount of frost on the evaporator 30. Therefore, in the case where no air flow occurs, it is difficult for the sensor 270 to accurately detect the amount of frost on the evaporator 30.

When the blower 70 is driven, in step S23, the temperature Htl of the heat generating element may be detected.

In the present embodiment, the temperature Ht1 of the heating element 273 may be detected at the point in time when the heating element 273 is turned on. That is, in the present disclosure, it is understood that the temperature of the heating element 273 may be detected immediately after the heating element 273 is turned on. Therefore, the detection temperature Ht1 of the heating element can be defined as the lowest temperature in the state where the heating element 273 is turned on.

Here, the temperature of the heating element 273 detected for the first time may be referred to as "first detected temperature (Ht 1)".

Next, in step S24, it is determined whether the first reference time T1 has elapsed while the heat generating element 273 is turned on.

When the heating element 273 is maintained in the opened state, the temperature detected by the sensing element 274 (i.e., the temperature Ht1 of the heating element 273) may continuously rise. However, when the heating element 273 is maintained in the opened state, the temperature of the heating element 273 may gradually rise and converge to the highest temperature point.

Here, the first reference time T1 to maintain the heating element 273 in the on state may be 3 minutes, but is not limited thereto.

When a predetermined period of time has elapsed while the heating element 273 is turned on, the heating element 273 is turned off in step S25.

As shown in fig. 11, the heating element 273 may be turned on and then turned off at the first reference time T1. When the heat generating element 273 is closed, the air flowing through the bypass passage 230 can rapidly cool the heat generating element 273. Therefore, the temperature Ht of the heating element 273 can be rapidly reduced.

However, when the off state of the heating element 273 is maintained, the temperature Ht of the heating element may gradually decrease, and the rate of decrease thereof significantly decreases.

Next, in step S26, the temperature Ht2 of the heating element may be detected.

That is, the temperature Ht2 of the heating element is detected by the sensing element 274 at a specific point in time S2 in a state where the heating element 273 is turned off.

In the present embodiment, the temperature Ht2 of the heating element can be detected at the point in time when the heating element 273 is turned off. That is, in the present disclosure, the temperature may be detected immediately after the heating element 273 is turned off. Therefore, the detection temperature Ht2 of the heating element can be defined as the highest temperature in the off state of the heating element 273.

Here, the temperature of the heating element 273 detected for the second time may be referred to as "second detected temperature (Ht 2)".

In summary, the temperature Ht of the heating element may be detected first at the point in time S1 when the heating element 273 is turned on, and may be detected additionally at the point in time S2 when the heating element 273 is turned off. In this case, the first detected temperature Ht1 detected for the first time may be the lowest temperature in the state where the heating element 273 is turned on, and the second detected temperature Ht2 detected in addition may be the highest temperature in the state where the heating element 273 is turned off.

Next, in step S27, it is determined whether the temperature steady state has been reached.

Here, the temperature steady state may refer to a state in which no internal refrigerator load occurs, i.e., a state in which cooling of the storage chamber is normally performed. In other words, being in a temperature stable state may mean that the opening/closing operation of the refrigerator door is not performed, or that there is no defect in the sensor 270 or components for cooling the storage compartment (e.g., the compressor and the evaporator).

That is, the sensor 270 can accurately detect the amount of frost on the evaporator 30 by determining whether temperature stabilization has been achieved.

In the present embodiment, in order to determine that the temperature steady state is reached, the amount of temperature change of the freezing chamber for a predetermined period of time may be determined. Alternatively, in order to determine that the temperature steady state is reached, the amount of temperature change of the evaporator 30 may be determined within a predetermined period of time.

For example, a state in which the temperature of the freezing chamber or the temperature of the evaporator 30 does not change by more than 1.5 degrees within a predetermined period of time may be defined as a temperature steady state.

As described above, after the heating element 273 is turned off, the temperature Ht of the heating element may be rapidly decreased immediately, and then, the temperature Ht of the heating element may be gradually decreased. Here, whether or not the temperature stabilization has been achieved may be determined by determining whether or not the temperature Ht of the heating element is normally lowered after the rapid lowering.

When the temperature steady state is reached, in step S28, a temperature difference Δht between the temperature Ht1 detected when the heating element 273 is on and the temperature Ht2 detected when the heating element 273 is off may be calculated.

In step S29, it is determined whether the temperature difference Δht is smaller than a first reference temperature value.

Specifically, when the amount of frost on the evaporator 30 is large, the flow rate of air flowing into the bypass passage 230 increases, and thus the cooling amount of the heating element 273 by the air flowing through the bypass passage 230 increases. When the cooling amount increases, the temperature Ht2 of the heating element detected immediately after the heating element 273 is turned off may be relatively low, as compared with the case where the amount of frost on the evaporator 30 is small.

As a result, when the amount of frost on the evaporator 30 is large, the temperature difference Δht may be small. Therefore, the amount of frost on the evaporator 30 can be determined by the temperature difference Δht. The first reference temperature value may be, for example, 32 degrees.

Next, when the temperature difference Δht is smaller than the first reference temperature value, in step S30, a defrosting operation is performed.

When the defrosting operation is performed, the defrosting device 50 is driven, and heat generated by the heater is transferred to the evaporator 30, so that frost generated on the surface of the evaporator 30 is melted.

On the other hand, when the temperature steady state is not reached in step S27, or when the temperature difference Δht is greater than or equal to the first reference temperature value in step S29, the algorithm ends without performing the defrosting operation.

In the present embodiment, the temperature difference Δht may be defined as a "logic temperature" for detecting frosting. The logic temperature may be used as a temperature to determine a time point of a defrosting operation of the refrigerator, and may be used as a temperature to determine a time point of the heating element 273 being turned on, which will be described later.

Fig. 12 is a flowchart illustrating a control method for determining an operating time point of a heating element according to one embodiment of the present disclosure. The present embodiment can be understood as a control method for determining the point of time at which the heating element 273 is turned on in fig. 10 (step S21).

Referring to fig. 11 and 12 together, in step S31, the heating element 273 may be turned off. Here, step S31 may refer to step S25 of fig. 10 described above. That is, the present embodiment can be understood as the control method after step S25.

When the heat generating element 273 is turned off, in step S32, it is determined whether the logic temperature Δht is smaller than the second reference temperature value.

It is possible to determine whether the logic temperature deltaht is smaller than the second reference temperature value in order to detect the amount of frost on the evaporator 30.

For example, the second reference temperature value may be 35 degrees.

Specifically, in fig. 10, the first reference temperature value for performing the defrosting operation has been described as 32 degrees. In this case, the second reference temperature value may be set to be greater than the first reference temperature value. That is, even when the defrosting operation is completed, the amount of frost on the evaporator 30 may be large, and thus the amount of frost on the evaporator 30 may be detected again.

When the logic temperature Δht is less than the second reference temperature value, it is determined whether the accumulated operating time of the freezing chamber has reached the second reference time in step S33. The second reference time may be, for example, 1 hour.

Next, when the logic temperature Δht is less than the second reference temperature value, it may be determined whether the blower 70 is being driven in step S34.

When the blower 70 is driven, it is determined in step S35 whether a temperature steady state is reached, and when the temperature steady state is reached, the heat generating element 273 is turned on in step S36.

Here, the temperature steady state may refer to a state in which no internal refrigerator load occurs or a state in which cooling of the storage chamber is normally performed. In other words, being in a temperature stable state may mean that the opening/closing operation of the refrigerator door is not performed, or that there is no defect in the sensor 270 or components for cooling the storage compartment (e.g., the compressor and the evaporator).

In the present embodiment, in order to determine the temperature steady state, the heating element 273 may be turned on/off at predetermined time intervals. For example, in determining the temperature steady state, the heating element 273 may be turned on/off at predetermined time intervals. In this case, the time point at which the heating element 273 is turned on/off to determine the temperature steady state may be the time point at which the blower 70 is turned on (S0).

That is, the heating element 273 may be turned on/off at predetermined time intervals immediately after the blower 70 is turned on. For example, when the blower 70 is driven, the heating element 273 may be repeatedly turned on/off every 10 seconds.

Further, by detecting the temperature variation of the temperature (Ft) of the freezing chamber or the temperature (Ht) of the heating element within the predetermined period of time, it is determined whether the detected temperature variation of the freezing chamber temperature (Ft) and the temperature variation of the heating element temperature (Ht) are less than a third reference temperature value. For example, the third reference temperature value may be 0.5 degrees, but is not limited thereto.

As shown in fig. 11, since the blower fan 70 is driven, the temperature Ft of the freezing chamber may gradually decrease. In addition, by turning on/off the heating element 273, the temperature Ht of the heating element can be increased by a certain amount.

In the present embodiment, the case where the detected change amount of the temperature (Ft) of the freezing chamber and the detected change amount of the temperature (Ht) of the heating element are smaller than the third reference temperature value may be determined as the temperature steady state.

On the other hand, in step S32, when the logic temperature is equal to or higher than the second reference temperature value, or in step S33, when the accumulated operation time does not reach the second reference time, the process returns to step S31.

Further, in step S34, when the blower is not driven, or in step S35, when the temperature steady state is not reached, the process returns to step S31.

Meanwhile, in the present embodiment, it is described that the amount of frost on the evaporator 30 is detected based on the temperature difference between the first detection temperature Ht1 detected in the state where the heating element 273 is turned on and the second detection temperature Ht2 detected in the state where the heating element 273 is turned off.

Alternatively, however, the temperature of the heating element 273 may be detected in a state where the heating element is turned on. The amount of frost on the evaporator 30 may be detected based on a temperature difference between a first detection temperature (Ht 1) which is the lowest value of the detection temperatures of the heating elements and a second detection temperature (Ht 2) which is the highest temperature of the detection temperatures of the heating elements.

That is, the amount of frost on the evaporator 30 can be detected by means of the detection temperatures Ht1 and Ht2 in the state where the heating element 273 is turned on, without detecting the temperature of the heating element in the state where the heating element 273 is turned off.

According to the method of controlling the refrigerator, the point of time when defrosting is required can be accurately determined using a sensor having an output value that is changed according to the amount of frost on the evaporator in the bypass passage. Therefore, when the amount of frost is large, a rapid defrosting operation can be performed, and when the amount of frost is small, a phenomenon of starting defrosting can be prevented.

Claims

1. A refrigerator, the refrigerator comprising:

an inner housing configured to define a storage space;

a cooling duct configured to guide air flowing in the storage space and define a heat exchange space together with the inner case;

an evaporator disposed in the heat exchange space;

a bypass passage provided on the cooling duct and configured to allow air to flow to bypass the evaporator;

a sensor disposed in the bypass passage and including a heating element and a sensing element configured to detect a temperature of the heating element; and

A controller configured to detect an amount of frost on the evaporator,

wherein a first detection temperature of the heating element is detected in a state where the heating element is turned on,

detecting a second detected temperature of the heating element in a state where the heating element is turned off,

wherein the controller is configured to perform a defrosting operation of the evaporator when a temperature difference between the first detected temperature and the second detected temperature is less than a first reference value,

wherein the sensing element detects the first detected temperature at a first point in time and the sensing element detects the second detected temperature at a second point in time, wherein the second point in time is later than the first point in time, and

wherein the temperature difference is a positive value and the temperature difference decreases as the amount of frost on the evaporator becomes greater.

2. The refrigerator of claim 1, wherein the second detected temperature is higher than the first detected temperature.

3. The refrigerator of claim 1, further comprising a blower for cooling the storage space, and

wherein the heating element is turned on while the blower is driven.

4. The refrigerator of claim 1, wherein the heating element is turned off when the heating element is turned on for a predetermined period of time.

5. The refrigerator of claim 1, wherein the controller is configured to determine whether a temperature steady state has been reached based on a temperature variation of the storage space for a predetermined period of time or a temperature variation of the evaporator for a predetermined period of time.

6. The refrigerator of claim 1, wherein the sensing element that detects the first detected temperature and the sensing element that detects the second detected temperature are the same.

7. A refrigerator, the refrigerator comprising:

an inner housing configured to define a storage space;

a cooling duct configured to guide a flow of air in the storage space and define a heat exchange space together with the inner case;

an evaporator disposed in the heat exchange space;

A controller configured to detect an amount of frost on the evaporator,

detecting a second detected temperature of the heating element after detecting a first detected temperature of the heating element in a state where the heating element is turned on,

wherein the temperature difference is a positive value and decreases as the amount of frost on the evaporator becomes larger, and

wherein the sensing element detects the first detected temperature at a first point in time and the sensing element detects the second detected temperature at a second point in time, wherein the second point in time is later than the first point in time.

8. The refrigerator of claim 7, wherein the second detected temperature is higher than the first detected temperature.

9. The refrigerator of claim 7, wherein the bypass passage is provided to face the evaporator in a left-right width range of the evaporator.

10. A refrigerator, the refrigerator comprising:

an inner housing configured to define a storage space;

an evaporator disposed in the heat exchange space;

a controller configured to detect an amount of frost on the evaporator,

wherein the controller is configured to determine whether a temperature steady state has been reached based on a temperature variation of the storage space or a temperature variation of the evaporator for a predetermined period of time, and

Wherein the controller is configured to perform the defrosting operation when the temperature steady state is reached.

11. A refrigerator, the refrigerator comprising:

an inner housing configured to define a storage space;

an evaporator disposed in the heat exchange space;

a controller configured to detect an amount of frost on the evaporator,

Wherein the controller is configured to determine whether a temperature difference between the first detected temperature and the second detected temperature is smaller than a second reference difference after the heating element is turned off, and

wherein the heating element is turned on when a temperature difference between the first detected temperature and the second detected temperature is smaller than the second reference difference.

12. The refrigerator of claim 11, wherein the heating element is turned on based on an accumulated cooling operation time of the storage space when a temperature difference between the first detected temperature and the second detected temperature is less than the second reference difference.

13. A refrigerator, the refrigerator comprising:

an inner housing configured to define a storage space;

an evaporator disposed in the heat exchange space;

A controller configured to detect an amount of frost on the evaporator,

wherein the controller is configured to perform a defrosting operation of the evaporator when a temperature difference between the first detected temperature and the second detected temperature is less than a first reference value, and

wherein the heating element is turned on while the storage space of the refrigerator is being cooled.