CN111771092B

CN111771092B - Refrigerator with a door

Info

Publication number: CN111771092B
Application number: CN201880088953.4A
Authority: CN
Inventors: 金成昱; 朴景培; 崔相福; 池成
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2018-02-23
Filing date: 2018-10-25
Publication date: 2022-04-15
Anticipated expiration: 2038-10-25
Also published as: EP3757487A4; AU2018409749A1; US20200370815A1; EP3757487A1; AU2018409749B2; CN111771092A; CN114674108A; CN114674108B; KR20190101669A; KR102627972B1; WO2019164084A1

Abstract

The refrigerator of the present invention includes: an inner case for forming a storage chamber; a cool air duct for guiding air flowing in the storage chamber and forming a heat exchange space together with the inner case; an evaporator located in a heat exchange space between the inner case and the cold air duct; a bypass flow passage provided in a concave shape from the cold air duct and allowing air to flow while bypassing the evaporator; a sensor provided in the bypass flow passage and having an output value that varies according to a flow rate of air flowing through the bypass flow passage; a defrosting device which removes frost formed on the surface of the evaporator; and a control unit for controlling the defrosting device based on a value output from the sensor.

Description

Refrigerator with a door

Technical Field

The present specification relates to a refrigerator.

Background

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

The storage space may be divided into a refrigerating storage space or a freezing storage space according to a 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, so as to be heat-exchanged 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-exchanges with the evaporator, thereby frosting on the surface of the evaporator.

Since the flow resistance of the 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, heat exchange efficiency of the evaporator may deteriorate, and thus power consumption may increase.

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

A variable defrost cycle method is disclosed in korean patent publication No. 2000-0004806 as a prior art document.

In the prior art document, the cumulative operating time of the compressor and the external temperature are used to regulate the defrost cycle.

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

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

Therefore, there are disadvantages in that defrosting cannot be started even if a large amount of frost is formed, thereby deteriorating cooling performance, or defrosting is started even if the amount of frost is low, thereby increasing power consumption due to unnecessary defrosting.

Disclosure of Invention

Technical problem

The present invention provides a refrigerator capable of determining whether to perform a defrosting operation by using a parameter that varies according to an amount of frost on an evaporator.

Further, the present invention provides a refrigerator capable of accurately determining a time point at which defrosting is required according to an amount of frost on an evaporator by using a bypass channel for sensing frost formation.

Further, the present invention provides a refrigerator capable of minimizing the length of a passage for sensing frost formation.

Further, the present invention provides a refrigerator capable of accurately determining a time point requiring defrosting even if the accuracy of a sensor for determining the time point requiring defrosting is low.

Further, the present invention provides a refrigerator capable of preventing frost from being formed around a sensor for sensing frost formation.

Further, the present invention provides a refrigerator capable of preventing liquid from being introduced into a bypass passage for sensing frost formation.

Technical scheme

A refrigerator for achieving the above objects includes a cool air duct inside an inner case, the cool air duct being configured to define a storage space, and the cool air duct defining a heat exchange space together with the inner case.

An evaporator is disposed in the heat exchange space, a bypass passage is disposed to be recessed in the cool air duct, and a sensor is disposed in the bypass passage.

In the present invention, the sensor may be a sensor having an output value that varies according to the flow rate of air flowing through the bypass passage, and the point in time at which defrosting of the evaporator is required may be determined by using the output value of the sensor.

The refrigerator according to the embodiment includes a defroster configured to remove frost accumulated on a surface of the evaporator, and a controller configured to control the defroster based on an output value of the sensor. When it is determined that defrosting is required, the controller may operate the defroster.

In this embodiment, the sensor may include: a heating element; a sensing element configured to sense a temperature of the heat generating element; and a sensor PCB on which the heating element and the sensing element are mounted.

The sensor may also include a sensor housing configured to enclose the heat-generating element, the sensing element, and the sensor PCB.

In this embodiment, when the difference between the temperature sensed by the sensing element in the state where the heating element is turned on and the temperature sensed by the sensing element in the state where the heating element is turned off is equal to or less than the reference temperature value, it may be determined that defrosting is required.

In this embodiment, the refrigerator may further include a passage cover configured to cover the bypass passage, thereby separating the bypass passage from the heat exchange space.

In this embodiment, the cool air duct may further include a vertically extending surface that is a surface defining the bypass passage, and the passage cover may include: a cover plate configured to cover the bypass passage; and a baffle plate extending from the cover plate, the baffle plate protruding downward from the vertically extending surface in a state where the cover plate covers the bypass passage, whereby a flow rate of air flowing through the bypass passage before frosting can be reduced.

In this embodiment, the bypass passage may extend vertically from the vertically extending surface in a straight line shape such that the length of the bypass passage is minimized.

The baffle protruding to the outside of the bypass passage may further include: a tailgate extending continuously from the cover plate, the tailgate disposed adjacent the evaporator; a plurality of side dams extending from the tailgate, the plurality of side dams being spaced apart from one another in a left-right direction; and a front baffle connected to the plurality of side baffles, spaced apart from the back baffle, and disposed on an opposite side of the evaporator relative to the back baffle.

In this embodiment, the cool air duct may further include an inclined surface extending to be inclined from an end of the vertically extending surface and configured to guide air toward the evaporator.

In this embodiment, the cool air duct may further include a groove provided in the tailgate, the groove being configured to define a passage for allowing the air flowing along the inclined surface to flow toward the evaporator. The slot may provide an air path and be defined in the tailgate.

In this embodiment, the sensor may be disposed spaced apart from the bottom surface of the bypass channel and the channel cover to prevent frost from forming around the sensor within the bypass channel.

The sensor may be disposed to be spaced apart from the inlet and outlet of the bypass passage so as to improve sensing accuracy of the sensor, and may be disposed in the bypass passage at a point where the distance between the bottom wall and the cover plate is bisected.

In this embodiment, the bypass passage may be disposed not to vertically overlap the cool air inflow hole, thereby preventing the air discharged from the outlet of the bypass passage from being affected by the flow rate of the air introduced into the cool air inflow hole.

In addition, the outlet of the bypass passage may be disposed outside a restricted area having a diameter greater than that of a blower disposed in the cool air duct with respect to the center of the blower.

In this embodiment, a blocking rib may be provided above the bypass passage in the cool air duct to prevent liquid from being introduced into the bypass passage.

For example, the barrier rib may have a left-right minimum length greater than a left-right minimum width of the bypass passage, and the entire bypass passage in the left-right direction may be disposed to overlap the barrier rib in the vertical direction.

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 varies according to the amount of frosting on the evaporator in the bypass passage, the time point at which defrosting is required can be accurately determined.

In addition, in the present invention, since the bypass passage extends vertically from the cool air duct in a straight shape, the length of the bypass passage can be minimized.

Further, in the present invention, since the sensor according to the present embodiment is provided at a point in the bypass channel where the flow change is small, and is provided in the channel center region in the fully developed flow region.

In addition, in the present invention, in an embodiment, the sensor may be disposed to be spaced apart from the bottom surface of the bypass channel and the channel cover to prevent frost from being formed around the sensor.

In addition, in the case of the present invention, in an embodiment, since the channel cover includes the baffle protruding to the outside of the bypass channel, the flow rate in the bypass channel before frosting can be minimized to improve the accuracy of determining the point in time at which defrosting is required by the sensor.

In addition, according to the present invention, a barrier rib may be provided above the bypass passage to prevent liquid from being introduced into the bypass passage.

Drawings

Fig. 1 is a schematic longitudinal sectional view of a refrigerator according to one 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 illustrating a state in which the passage cover and the sensor are separated from each other in the cool air duct.

Fig. 4 is a view showing air flows in the heat exchange space and the bypass passage before and after frosting.

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

FIG. 6 is a diagram of a sensor according to an embodiment of the present invention.

Fig. 7 is a graph showing heat flow around the sensor according to the air flow flowing through the bypass channel.

Fig. 8 is a diagram showing the position of the sensor in the bypass passage.

Fig. 9 is a diagram showing the airflow pattern in the bypass passage.

Fig. 10 is a diagram showing an air flow in a state where the sensor is mounted in the bypass passage.

Fig. 11 is a view illustrating an arrangement of a bypass passage and a passage cover in a cool air duct according to an embodiment of the present invention.

Fig. 12 is an enlarged view illustrating a bypass passage and a rib for preventing entry of defrost water according to an embodiment of the present invention.

Fig. 13 is a diagram illustrating a baffle of a passage cover according to one embodiment of the present invention.

Fig. 14 is a graph showing a change in temperature sensed by the sensor according to the protruding length of the baffle.

Fig. 15 is a sectional view of the baffle taken along line a-a of fig. 13.

Fig. 16 is a diagram showing that the airflow changes depending on whether or not a groove is provided in the baffle.

Fig. 17 is a graph showing the variation of the temperature sensed by the sensor according to the length of the slot defined in the baffle.

Fig. 18 is a view illustrating an air flow introduced into a heat exchange space according to an embodiment of the present invention.

Fig. 19 is a control block diagram of a refrigerator according to an embodiment of the present invention.

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. It should be noted that identical or similar components in the figures are denoted by the same reference numerals as much as possible, even though they are shown in different figures. Further, in the description of the embodiments of the present disclosure, when it is determined that a detailed description of a well-known configuration or function interferes with understanding of the embodiments of the present disclosure, the detailed description will be omitted.

Also, 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 only to distinguish the corresponding component from other components and does not define the nature, order, or sequence of the corresponding components. It will be understood that when an element is "connected," "coupled," or "engaged" to another element, the former may be directly connected or engaged to the latter, or the latter may be "connected," "coupled," or "engaged" to the latter with a third element interposed therebetween.

Fig. 1 is a schematic longitudinal sectional view of a refrigerator according to one embodiment of the present invention, fig. 2 is a perspective view of a cool air duct according to one embodiment of the present invention, and fig. 3 is an exploded perspective view illustrating a state in which a channel 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 one embodiment of the present invention may include an inner case 12 defining a storage space 11.

The storage space may include one or both 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 disposed 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 cold air duct 20 and the rear wall 13 of the inner case 12 and then exchange heat with the evaporator 30. Thereafter, the 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 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 connected to each other, the cool air passage 212 may be disposed between the first duct 210 and the second duct 220.

In addition, a cold air inflow hole 221 may be defined in the second duct 220, and a cold air discharge hole 211 may be defined in the first duct 210.

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

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

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

According to this arrangement, when the amount of frost on the evaporator 30 increases, the amount of air passing through the evaporator 30 decreases.

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

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

The frost sensing part may include a bypass passage 230, the bypass passage 230 bypassing at least a portion of the air flowing through the heat exchange space 222, and a sensor 270 disposed in the bypass passage 230.

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

The bypass passage 230 may be provided by recessing a portion of the first duct 210 or the second duct 220 in a direction away from the evaporator 30.

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

The bypass channel 230 may be disposed to face the evaporator 30 within the left and right width of the evaporator 30 such that the air in the heat exchange space 222 bypasses to the bypass channel 230.

The frost sensing part may further include a passage cover 260 allowing the bypass passage 230 to be spaced apart from the heat exchange space 222.

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

The passage cover 260 may include a cover plate 261, an upper extension 262 extending upward from the cover plate 261, and a baffle 263 disposed below the cover plate 261. The specific shape of the passage cover 260 will be described later in detail.

Fig. 4 (a) shows the airflow before frosting, and fig. 4 (b) shows the airflow after frosting. In this embodiment, as an example, it is assumed that the state after the end of the defrosting operation is the state before frosting.

First, referring to (a) of fig. 4, in the case where there is no frost on the evaporator 30 or the amount of frost 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 the bypass passage 230 (see arrow B).

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

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

In this embodiment, the sensor 270 may have an output value that varies according to a variation in the flow rate of air flowing through the bypass passage 230. Therefore, whether defrosting is required can be determined 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 disposed in a bypass passage, fig. 6 is a view of a sensor according to an embodiment of the present invention, and fig. 7 is a view showing heat flow around the sensor according to air flow flowing through the bypass passage.

Referring to fig. 5 to 7, the sensor 270 may be disposed at a point in the bypass passage 230. Accordingly, the sensor 270 may contact the air flowing along the bypass passage 230, and an output value of the sensor 270 may be changed in response to a change in the amount of airflow.

The sensor 270 may be disposed at a position spaced apart from each of the inlet 231 and the outlet 232. The specific location of the sensor 270 in the bypass passage 230 is described later with reference to the drawings.

Since the sensor 270 is disposed on the bypass passage 230, the sensor 270 can face the evaporator 30 within the right and left width of the evaporator 30.

The sensor 270 may be, for example, a heat-generating temperature sensor. In particular, the sensor 270 may include: a sensor PCB 272; a heating element 273 mounted on the sensor PCB 272; and a sensing element 274 mounted on the sensor PCB 272 to sense the 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 heat generating 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 as the amount of cooling of the heat generating element 273 by the air flowing through the bypass passage 230 increases.

The sensor PCB 272 may determine a difference between a temperature sensed by the sensing element 274 in a state where the heating element 273 is disconnected and a temperature sensed by the sensing element 274 in a state where the heating element 273 is opened.

The sensor PCB 272 may determine whether a difference between states in which the heating element 273 is turned on/off is less than a reference difference.

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

On the other hand, when the amount of frost formed on the evaporator 30 is large, the flow rate of air flowing to the bypass passage 230 is large. Accordingly, the heat flow and the cooling amount of the heat generating element 273 become large due to the air flowing along the bypass passage 230.

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

Therefore, in this embodiment, when the difference between the temperature sensed by the sensing element 274 in the state where the heater element 273 is turned on and the temperature sensed by the sensing element 274 in the state where the heater element 273 is turned off is less than the reference temperature difference, it can be determined that defrosting is required.

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

The sensor 270 may further include a sensor housing 271 to prevent air flowing through the bypass channel 230 from directly contacting the sensor PCB 272, the heat generating element 273, and the temperature sensor 274.

In the sensor housing 271, the wire connected to the sensor PCB 271 is drawn out in a state where one side of the sensor housing 271 is opened. Thereafter, the opening portion may be covered by the cover portion.

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

Fig. 8 is a diagram showing a mountable position of a sensor in a bypass passage, fig. 9 is a diagram showing an airflow pattern in the bypass passage, and fig. 10 is a diagram showing an airflow in a state where the sensor is mounted in the bypass passage.

Referring to fig. 5 and 8 to 10, the passage cover 260 may cover a portion of the bypass passage 230 in a vertical direction.

Thus, air may flow along the area of the bypass passage 230 (spaced apart from the heat exchange space) where the passage cover 260 is substantially present.

As described above, the sensor 270 may be disposed to be spaced apart from the inlet 231 and the outlet 232 of the bypass passage 230.

The sensor 270 may be disposed at a position where the sensor 270 is less affected by changes in the airflow through the bypass passage 230.

For example, the sensor 270 may be disposed at a position (hereinafter, referred to as an "inlet reference position") spaced at least 6Dg (or 6 times the channel diameter) from the inlet of the bypass channel 230 (actually, the lower end of the channel cover 260).

Alternatively, the sensor 270 may be disposed at a position (hereinafter referred to as "outlet reference position") spaced at least 3Dg (or 3 times the channel diameter) from the outlet of the bypass channel 230 (actually, the upper end of the channel cover 260).

The variation in the air flow is severe when air is introduced into the bypass passage 230 or discharged from the bypass passage 230.

If the variation in the airflow is large, it may be erroneously determined that defrosting is required although the amount of frosting is small. Therefore, in this embodiment, the sensor 270 is installed at a position where the flow rate change is small, when the air flows along the bypass passage 230, to reduce the detection error.

For example, the sensor 270 may be disposed in a range between an inlet reference position and an outlet reference position. The sensor 270 may be disposed closer to the outlet reference position than the inlet reference position. Thus, the sensor 270 may be positioned closer to the outlet 232 than the inlet 231 in the bypass passage 230.

Since the flow is stable at least at the inlet reference position and the flow is stable up to the outlet reference position, air having a stable flow may contact the sensor 270 if the sensor 270 is disposed near the outlet reference position.

Accordingly, since the flow rate is not affected except for the flow rate change caused by the amount of frost, the sensing accuracy of the sensor 270 can be improved.

In addition, referring to fig. 9, the farther from the inlet 231 in the bypass passage 230, the air becomes in the form of a fully developed flow.

Since the sensor 270 is very sensitive to changes in airflow, the sensor 270 can accurately sense changes in flow when the sensor 270 is disposed in the center of the bypass passage 230 (at which point fully developed flow occurs).

Thus, as shown in FIG. 10, the sensor 270 may be mounted in a central region within the bypass channel 230.

Here, the central region of the bypass passage 230 is a region including a portion where the distance between the bottom wall 236 of the recessed portion of the bypass passage and the passage cover 260 is halved. That is, a portion of the sensor 270 may be disposed at a point where the distance between the bottom wall 236 of the recessed portion of the bypass channel 230 and the channel cover 260 is bisected.

Referring to fig. 10, the sensor 270 may be spaced from the bottom wall 230 of the bypass channel 236 and the channel cover 260. Thus, a portion of the air in the bypass channel 230 may flow through the space between the bottom wall 236 and the sensor 270, while another portion of the air may flow through the space between the sensor 270 and the channel cover 260.

In summary, the sensor 270 must be installed in the center region of the channel at the point where the air flow in the bypass channel 230 is minimally changed and at the point where the fully developed flow flows in order to improve the sensing accuracy.

With this arrangement, the sensor 270 can react sensitively to changes in the airflow depending on the amount of frost. That is, the temperature change sensed by the sensor 270 may increase.

As described above, when the temperature variation sensed by the sensor 270 increases, even if the temperature sensing accuracy of the sensor 270 itself is lowered, the time point at which defrosting is required can be determined. Since the temperature sensing accuracy of the sensor itself is related to price, even if the sensor 270 having a relatively low price due to low accuracy is used, the time point at which defrosting is required can be determined.

Since the temperature sensing accuracy of the sensor itself is related to price, even if the sensor 270 having a relatively low price due to low accuracy is used, the time point at which defrosting is required can be determined.

Referring to fig. 11, the lower end 260a of the passage cover 260 may be disposed at a height similar to that of the lower end of the evaporator 30, or at a height lower than that of the lower end of the evaporator 30.

According to this arrangement, when the amount of frost on the evaporator 30 increases, air can easily flow to the bypass passage 230.

In this embodiment, since the blower fan is disposed in the cold air duct 20, a portion of the cold air inflow hole 221 of the cold air duct 20 may be used as a low pressure area when the blower fan is rotated.

Also, since the air flows upward along the evaporator 30, the lower side of the evaporator 30 may serve as a high pressure area, and the upper side of the evaporator 30 may serve as a low pressure area.

In this embodiment, the upper end 260b of the access cover 260 may be disposed in a low pressure region.

Accordingly, since the lower end 260a of the passage cover 260 is disposed in the high pressure region and the upper end 260b is disposed in the low pressure region, the air can be flowed toward the bypass passage 230.

Further, in this embodiment, the upper end 260b of the passage cover 260 may be disposed higher than the evaporator 30. Accordingly, it is possible to reduce a phenomenon that the air discharged from the bypass passage 230 is affected by the air passing through the evaporator.

The bypass passage 230 may be disposed not to vertically overlap with the cool air inflow hole 221. This is to prevent the air discharged from the outlet 232 of the bypass passage 230 from being affected by the air introduced into the cold air inflow hole 221.

Also, the outlet 232 of the bypass passage 230 may be disposed lower than the center C of the blower fan. Also, the outlet 230 of the bypass passage 232 may be disposed lower than the lowest point of the cool air inflow hole 221.

In this embodiment, the cool air inflow hole 221 has a diameter D1, and the blower fan has a diameter D2. The diameter D2 of the blowing fan may be larger than the diameter D1 of the cooling air inflow hole 221.

A restriction region having a diameter D3 larger than the diameter D2 of the blower fan may be set based on the center C of the blower fan, and the outlet 232 of the bypass passage 230 may be disposed in a region outside the restriction region having a diameter D3.

Also, in order to minimize the length of the bypass passage 230, the bypass passage 230 may vertically extend in a straight line shape in an area outside the restriction area.

Here, although not limited, the diameter D3 may be set to 1.5 times or more the blower fan diameter.

Since air is introduced into the cold air duct 20 through the air inflow hole 221, the flow rate of the cold air flowing into the hole 221 is fast.

Also, since the flow rate of the cool air flowing into the hole 221 is fast, the flow rate of the air in the region of the diameter D3 is fast.

If the outlet 232 of the bypass passage 230 is disposed in the restricted area, the airflow in the bypass passage 230 varies due to the influence of the rapid flow velocity, and the sensing accuracy of the sensor 270 is degraded.

Therefore, in this embodiment, the bypass passage 230 may extend in a straight shape so as not to be affected by the air having a rapid flow velocity around the cooling air inflow hole 221 while reducing the length of the bypass passage 230, and the outlet 232 may be disposed outside the restricted area.

Referring to fig. 10 and 12, since air flowing through the bypass passage 230 contains moisture, frost may be formed in the bypass passage 230 due to a capillary phenomenon in a space between the sensor 270 and a wall defined by the bypass passage 230.

Thus, in this embodiment, the sensor 270 may be spaced from the bottom wall 236 of the bypass channel 230 and the channel cover 260 to prevent frost from forming in the channel.

Although not limited, the sensor 270 may be designed to be spaced at least 1.5mm from each of the bottom wall 236 and the access cover 260 (which may be referred to as a "minimum separation distance").

Accordingly, the depth D of the bypass channel 230 may be equal to or greater than (2 times the minimum separation distance) and the thickness of the sensor 270.

The left-right width W of the bypass channel 230 may be greater than the depth D.

If the left-right width W of the bypass passage 230 is greater than the depth D, the contact area between the air and the sensor 270 increases when the air flows toward the bypass passage 230, and thus, the temperature change sensed by the sensor 270 may increase.

The cold air duct 20 may be provided with a blocking rib 240 for preventing liquid or moisture such as defrost water, which is generated by melting during defrosting, from being introduced into the bypass passage 230.

The blocking rib 240 may be disposed above the outlet 232 of the bypass passage 230. The blocking rib 240 may have a protruding shape protruding from the cool air duct 20.

The barrier ribs 240 may allow the dropped liquid to be horizontally spread, thereby preventing the liquid from being introduced into the bypass channel 230.

The barrier ribs 240 may be horizontally disposed in a straight line shape, or may be disposed to be upwardly convex in a rounded shape.

The blocking ribs 240 may be disposed to overlap the entire left and right sides of the bypass channel 230 in the vertical direction, and may have minimum left and right lengths greater than the right and left widths of the bypass channel 230.

When the blocking rib 240 is provided in the cool air duct 20, the minimum left-right length of the blocking rib 240 may be set to be twice or less of the left-right width W since the blocking rib 240 serves as a flow resistance of air.

Since the blocking rib 240 is disposed closer to the bypass passage 230, the length of the blocking rib 240 may be shortened. On the other hand, the defrost water may flow through the barrier ribs 240 and then be introduced into the bypass passage 230.

Accordingly, the blocking rib 240 may be spaced apart from the bypass passage 230 in the vertical direction, and the maximum spaced distance may be set within the range of the left-right width W of the bypass passage 230.

The cool air duct 20 may include a sensor mounting groove 235 recessed to mount the sensor 270.

The cool air duct 20 may include a bottom wall 236 and two

side walls

233 and 234 for providing the bypass passage 230, and the sensor mounting groove 235 may be recessed into one or both of the

side walls

233 and 234.

In a state where the sensor 270 is mounted in the sensor mounting groove 235, the sensor 270 may be spaced apart from the bottom wall 236 and the passage cover 260 by the minimum spacing distance as described above.

Fig. 13 is a diagram illustrating a baffle of a passage cover according to an embodiment of the present invention, fig. 14 is a diagram illustrating a temperature sensed by a sensor varying according to a protruding length of the baffle, and fig. 15 is a cross-sectional view of the baffle taken along line a-a of fig. 13.

Fig. 16 is a graph showing a change in the gas flow depending on whether or not a groove is provided in the baffle, and fig. 17 is a graph showing a change in the temperature sensed by the sensor depending on the length of the groove defined in the baffle.

Referring to fig. 3, 8, and 12-18, the passage cover 260 may include a cover plate 261, an upper extension 262, and a baffle 263.

The cover plate 261 may cover the bypass passage 230 and may be provided in a thin plate shape. For example, the cover plate 261 may cover the bypass passage 230 in a spaced state from the bottom wall 236.

A seating groove 235a for seating the cover plate 261 may be vertically defined in the cool air duct 20. When the cover plate 261 is seated in the seating groove 235a, the outer surface of the cover plate 261 may provide a substantially continuous surface with respect to the cool air duct 20.

The upper extension 262 may also cover a portion of the bypass passage 230 and extend from the cover plate 261 to be inclined at a predetermined angle.

The upper extension 262 is configured to obliquely extend from the cover plate 261 corresponding to a portion (226: hereinafter, referred to as "upper inclined portion") of the cool air duct 20.

If the cool air duct 20 does not include the upper inclined portion, the upper extension portion 262 may be omitted, and the cover plate 261 may be provided in a linear shape.

The upper extension 262 covers only a portion of the bypass passage 230. Therefore, a portion of the bypass passage 230 is exposed to the outside as the outlet 232.

A portion of the baffle 263 is disposed outside the bypass passage 230, and the cover plate 261 covers the bypass passage 230. For example, the baffles 263 may protrude downward from the upper and lower extension surfaces 227 of the cool air duct 20.

Therefore, a portion of the baffle 263 is disposed in the bypass passage 230, and another portion protrudes downward from the bypass passage 230.

Specifically, the baffle 263 includes a rear baffle 267 disposed adjacent to the evaporator 30, a front baffle 264 spaced forward from the rear baffle 267, and a plurality of side baffles 265 and 266 connecting the front baffle 264 to the rear baffle 267. The plurality of

side dams

265 and 266 may be spaced apart from each other in the left-right direction. Although not limited, a plurality of

side dams

265 and 266 can be disposed parallel to each other.

The rear baffle 267 is a wall provided continuously with the cover plate 261. The plurality of

side guards

265 and 266 are walls extending forward from the back guard 267. The front barrier 264 is a wall that connects front ends of the plurality of

side barriers

265 and 266 to each other.

Front baffle 264 is disposed on the opposite side of evaporator 30 relative to rear baffle 267.

Thus, the bottom surface of the blocking plate 263 is opened. Accordingly, a guide passage 268 for guiding air to the bypass passage 230 is provided by the front barrier 264, the plurality of

side barriers

265 and 266, and the rear barrier 267.

The guide passage 268 is a passage communicating with the bypass passage 230 outside the bypass passage 230. The guide passage 268 also serves as a bypass passage.

In the cool air duct 20, the vertically extending surface 227 may be a substantially vertical surface in which the bypass passage 230 is provided.

The bypass passage 230 may extend vertically in a straight line shape from the vertically extending surface 227.

The cool air duct 20 may further include an inclined surface 228 extending from a lower end of the vertically extending surface 227. The inclined surface 228 may extend downward with increasing distance from the evaporator 30.

The inclined surface 228 is a surface that guides air in the storage space 11 to the heat exchange space 222.

Therefore, the air in the storage space 11 flows upward by the inclined surface 228 when viewed from the side surface of the heat exchange space 222.

In this embodiment, when the amount of frost accumulated on the evaporator 30 is small, the baffles 263 may be used to restrict the introduction of the air flowing toward the heat exchange space 222 into the bypass passage 230.

On the other hand, when the amount of frost accumulated on the evaporator 30 is large, the baffle 263 may be used to effectively guide the air introduced into the heat exchange space 222 to the bypass passage 230.

As described above, when the variation in the air flow amount is increased due to the large and small amounts of frost accumulated on the evaporator 30, the sensing accuracy of the sensor 270 can be improved by the shutter 263.

That is, if the variation in the air flow rate is large due to the generation of a large amount and a small amount of frost on the evaporator 30, the temperature sensed by the sensor 270 is large, and thus the time point at which defrosting is required can be accurately determined.

In addition, as described above, when the temperature variation sensed by the sensor 270 increases due to the large and small amounts of frost accumulated on the evaporator 30, even if the sensor 270 having low sensor accuracy is used, the point in time at which defrosting is required can be determined.

In this embodiment, the flow rate of the air introduced into the bypass passage 230 may vary according to the length of the baffle 263 protruding from the lower end of the vertically extending surface 227 (i.e., the boundary between the vertically extending surface 227 and the inclined surface 228).

Referring to fig. 14, the horizontal axis represents the protruding length of the baffle, and the vertical axis represents the temperature change before and after frosting.

When the protruding length of the baffle 263 is short, the flow rate of air flowing through the bypass passage 230 increases even before frost is formed.

When the flow rate of the air flowing through the bypass passage 230 is large before the frost is formed, the temperature change (e.g., the difference between the highest temperature and the lowest temperature) sensed by the sensor 270 is large. Therefore, the flow rate of the air flowing through the passage 230 of the air of the bypass passage 230 is also large, and the temperature change sensed by the sensor 270 is large.

As a result, a variation between the temperature sensed by the sensor 270 before frosting and the temperature sensed by the sensor 270 after frosting (e.g., a difference between the lowest temperature before frosting and the lowest temperature after frosting) is reduced.

On the other hand, when the protruding length of the baffle 263 is increased, the flow rate of air flowing through the bypass passage 230 before frosting is decreased. The temperature change sensed by sensor 270 before frosting is reduced.

On the other hand, since the temperature sensed by the sensor 270 after frosting varies greatly, the variation between the temperature sensed by the sensor 270 before frosting and the temperature sensed by the sensor 270 after frosting increases.

However, when the protruding length of the baffle 263 is too long, the flow rate of air flowing into the bypass passage 230 is reduced before and after frost formation. As a result, the variation between the temperature sensed by the sensor 270 before the frost formation and the temperature sensed by the sensor 270 after the frost formation is reduced.

Accordingly, the protruding length of the blocking plate 263 may be set to a value in the range of about 10mm to about 17mm such that the temperature change sensed by the sensor 270 before and after frosting is greater than the reference change.

The lower end of the blocking plate 263 may be horizontally disposed. For example, the front baffle 264 and the plurality of side baffles 265 and 266 may be disposed on substantially the same horizontal plane.

In this case, as shown in (a) of fig. 16, since the air in the storage space 11 flows upward along the inclined surface 228, when the air passing through the front baffle 264 among the obliquely flowing air collides with the rear baffle 267, the air flows toward the bypass passage 230 without flowing toward the evaporator 30.

In this case, the flow rate of the air flowing into the bypass passage 230 is increased regardless of the frosting amount.

In the case of the present embodiment, the accuracy of determining the point in time at which defrosting is required can be improved only when the flow rate of air flowing through the bypass passage 230 is minimized before frosting.

Accordingly, a groove 269 providing an air flow path may be defined in the rear baffle 267 such that air passing through the lower end of the front baffle 264 flows directly to the evaporator 30.

As shown in (b) of fig. 16, when the groove 269 is defined in the rear barrier 267, air flowing through the lower end of the front barrier 264 does not collide with the rear barrier 267 and thus does not directly flow to the evaporator 30.

In this embodiment, the air colliding with the front barrier 264 flows along the plurality of

side barriers

265 and 266 and then flows toward the rear barrier 267.

When the groove 269 is not defined in the back plate 267, the air flowing along the

side plates

265 and 266 does not flow to the bypass passage 230, but flows to the evaporator 30.

On the other hand, when the groove 269 is defined in the back plate 267, the air flowing along the

side plates

265 and 266 flows toward the bypass passage 230 through the groove 269.

Therefore, in this embodiment, the flow rate of the air flowing toward the bypass passage 230 may be actually determined by at least the flow rate of the air introduced directly into the guide passage 268 of the baffle 263 and the flow rate of the air introduced into the baffle 263 along the groove 269 after flowing along the periphery of the baffle 263.

In this embodiment, if the length of the groove 269 (height from the lower end of the baffle 262) is small, the flow rate of the air flowing into the bypass passage 230 is large, and when the length of the groove 269 increases, the flow rate of the air flowing into the bypass passage 230 decreases.

However, if the length of the slots 269 is too long, the flow rate of air flowing through the slots 269 increases after flowing along the side baffles 265 and 266, and the flow rate of air flowing into the bypass passage 230 increases even before frosting.

Therefore, in this embodiment, the length of the groove may be set to a value in the range of about 4mm to about 9mm, so that the flow rate of air flowing into the bypass passage 230 is minimized before frosting. Although not limited, the length of the groove 269 may be designed to be in the range of about 1/5 to about 1/2 of the protruding length of the baffle 263.

Fig. 19 is a control block diagram of a refrigerator according to a first embodiment of the present invention.

Referring to fig. 19, the refrigerator 1 according to one embodiment of the present invention may further include a defroster 50 operating to defrost the evaporator 30 and a controller 40 controlling the defroster 50.

The defroster 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 formed on the surface of the evaporator 30.

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

To determine the point in time when defrosting is required, the heating element 273 may be maintained in the on state for a certain time, and the temperature of the heating element 273 may be sensed by the sensing element 274.

After the heating element 273 is turned on for a certain time, the heating element 273 may be turned off, and the sensing element 274 may sense the temperature of the turned-off heating element 273. Also, the sensor PCB 272 may determine whether the maximum value of the temperature difference in the on/off state of the heating element 273 is equal to or less than a reference difference value.

Then, when the maximum value of the temperature difference value in the on/off state of the heating element 273 is equal to or less than the reference difference value, it is determined that defrosting is necessary. Accordingly, the defroster 50 may be turned on by the controller 40.

In the above, it has been described that it is determined whether the temperature difference of the on/off state of the heating element 273 in the sensor PCB 272 is equal to or less than the reference difference. On the other hand, the controller 40 may determine whether the temperature difference value in the on/off state of the heating element 273 is equal to or less than the reference difference value, and then control the defroster 50 according to the determination result.

Claims

1. A refrigerator, comprising:

an inner shell configured to define a storage space;

a cold air duct configured to guide an air flow within the storage space, the cold air duct configured to define a heat exchange space together with the inner casing;

an evaporator disposed in the heat exchange space between the inner case and the cool air duct;

a bypass passage provided to be recessed in the cool air duct, the bypass passage being configured to flow air to bypass the evaporator;

a passage cover configured to cover the bypass passage to separate the bypass passage from the heat exchange space;

a sensor provided in the bypass passage, the sensor having an output value that varies according to a flow rate of air flowing through the bypass passage;

a defroster configured to remove frost formed on a surface of the evaporator; and

a controller configured to control the defroster based on an output value of the sensor.

2. The refrigerator of claim 1, wherein the sensor comprises:

a heating element;

a sensing element configured to sense a temperature of the heat generating element; and

a sensor PCB, the heating element and the sensing element being mounted on the sensor PCB.

3. The refrigerator of claim 2, wherein the controller operates the defroster when a difference between a temperature sensed by the sensing element in a state where the heat generating element is turned on and a temperature sensed by the sensing element in a state where the heat generating element is turned off is equal to or less than a reference temperature value.

4. The refrigerator of claim 2, wherein the sensor further comprises a sensor housing configured to surround the heat generating element, the sensing element, and the sensor PCB.

5. The refrigerator of claim 1, wherein the channel cover is coupled to the cool air duct to cover the bypass channel extending vertically.

6. The refrigerator of claim 5, wherein the cool air duct includes a vertically extending surface, the vertically extending surface being a surface defining the bypass channel therein; and is

The passage cover includes:

a cover plate configured to cover the bypass passage; and

a baffle plate extending from the cover plate, the baffle plate protruding downward from the vertically extending surface in a state where the cover plate covers the bypass passage.

7. The refrigerator of claim 6, wherein the bypass channel extends vertically from the vertically extending surface in a straight line shape.

8. The refrigerator of claim 6, wherein the baffle further comprises:

a tailgate extending continuously from the cover plate, the tailgate disposed adjacent the evaporator;

a plurality of side dams extending from the tailgate, the plurality of side dams being spaced apart from one another in a left-right direction; and

a front baffle connected to the plurality of side baffles, spaced apart from the back baffle, and disposed on an opposite side of the evaporator relative to the back baffle.

9. The refrigerator of claim 8, wherein the baffle has an open bottom surface, and

the front baffle, the plurality of side baffles, and the rear baffle define a guide channel configured to guide air to the bypass channel.

10. The refrigerator of claim 8, wherein the cool air duct further comprises an inclined surface extending obliquely from an end of the vertically extending surface and configured to guide air toward the evaporator; and is

A groove is provided in the tailgate, the groove being configured to define a passage that allows air flowing along the inclined surface to flow toward the evaporator.

11. The refrigerator of claim 5, wherein the cool air duct includes a bottom wall and two side walls defining the bypass channel;

the passage cover includes a cover plate configured to cover the bypass passage in a state of being spaced apart from the bottom wall; and is

The sensor is disposed in the bypass channel spaced apart from the bottom wall and the cover plate.

12. The refrigerator of claim 11, wherein the sensor is disposed spaced apart from an inlet and an outlet of the bypass channel; and is

A portion of the sensor is disposed in the bypass channel at a point where the distance between the bottom wall and the cover plate is bisected.

13. The refrigerator of claim 12, wherein the sensor is disposed closer to the outlet than the inlet of the bypass channel.

14. The refrigerator of claim 5, wherein at least a portion of the bypass channel and the channel cover are disposed to face the evaporator within a range of a left-right width of the evaporator.

15. The refrigerator according to claim 5, wherein a blowing fan is provided in the cool air duct,

a cool air inflow hole for introducing cool air is defined in the cool air duct; and is

The bypass passage does not overlap the cold air inflow hole in a vertical direction.

16. The refrigerator of claim 15, wherein the outlet of the bypass passage is disposed in an area outside a restricted area having a diameter with respect to a center of the blowing fan greater than a diameter of the blowing fan.

17. The refrigerator of claim 16, wherein the outlet of the bypass passage is disposed higher than an upper end of the evaporator.

18. The refrigerator of claim 16, wherein a diameter of the restriction area is greater than 1.5 times or more a diameter of the blowing fan.

19. The refrigerator of claim 1, wherein a blocking rib is provided above the bypass channel in the cool air duct, the blocking rib being configured to block introduction of liquid into the bypass channel.

20. The refrigerator of claim 19, wherein a left-right minimum length of the blocking rib is greater than a left-right minimum width of the bypass channel; and is

The entire bypass passage in the left-right direction is disposed to overlap the barrier rib in the vertical direction.