KR102427017B1 - Defrosting device - Google Patents

Abstract

The present invention, a heater case through which an internal flow path and a heater receiving portion are not in communication with each other; a heat pipe having both ends inserted into the heater case through an inlet and an outlet of the inner flow path opened at both ends of the heater case and communicating with the internal flow path; and a heater inserted into the heater accommodating part to heat the working fluid in the internal flow path, wherein at least one heat transfer fin is provided in the internal flow path toward the inside so that heat transfer from the heater to the working fluid can be increased. Disclosed is a defrosting device that is formed to protrude.

Description

Defrosting device {DEFROSTING DEVICE}

The present invention relates to a defrosting device for removing frost on an evaporator provided in a refrigeration cycle.

A refrigerator is a device for storing food stored therein at a low temperature using cold air generated by a refrigeration cycle in which the process of compression-condensation-expansion-evaporation is continuously performed.

The refrigeration cycle in the refrigerating chamber consists of a compressor that compresses the refrigerant, a condenser that condenses the refrigerant in a high-temperature and high-pressure state compressed from the compressor through heat radiation, and It includes an evaporator for cooling the air. A capillary tube or an expansion valve is provided between the condenser and the evaporator to increase the flow rate of the refrigerant and lower the pressure so that the refrigerant flowing into the evaporator can easily evaporate.

As such, the evaporator provided in the refrigerating cycle lowers the surrounding temperature by using the cold air generated by the circulation of the refrigerant flowing through the cooling pipe. In this process, when a temperature difference with the surrounding air occurs, moisture in the air is condensed and frozen on the surface of the cooling tube to generate frost. The frost on the evaporator acts as a factor to lower the heat exchange efficiency of the evaporator.

As a defrosting operation to remove the frost formed on the evaporator, a defrosting method using a hot wire was conventionally used. However, in the defrosting structure using a hot wire, the proper temperature required for defrosting was not delivered to a specific part of the evaporator, causing a problem of energy loss.

Recently, a defrosting device having a new structure in which a working fluid heated by a heater flows through a heat pipe to perform defrosting has been developed.

In the defrosting apparatus, for smooth circulation of the working fluid, it is preferable that the working fluid receives as much heat as possible from the heater. However, in a structure in which the heater heats only the surface of the flow path through which the working fluid flows, there is a limitation in that the working fluid flowing inside the surface of the flow path is not sufficiently heated.

Therefore, in order to stabilize the circulation of the working fluid and improve the performance of the defrosting device, it is most important to increase heat transfer from the heater to the working fluid.

In addition, in a structure in which the heater is mounted on the heater case to transfer heat to the internal flow path through which the working fluid flows, the heater must be firmly attached to the heater case to increase heat transfer from the heater to the working fluid. However, the structure in which the heater is attached to the heater case is inferior in assembly property, and there is a possibility that moisture may penetrate into the heater.

Accordingly, research on a new heater fixing structure in which the heater can be easily and firmly fixed to the heater case and assembly defects can be reduced is being conducted.

A first object of the present invention is to provide a heater case having a novel structure in which heat transfer from a heater to a working fluid can be increased.

A second object of the present invention is to provide a heater fixing structure in which a heater is firmly fixed to a heater case and assembly defects can be reduced.

In order to achieve the first object of the present invention, the defrosting apparatus of the present invention includes a heater case through which an internal flow path and a heater accommodating part are not communicated with each other; a heat pipe having both ends inserted into the heater case through an inlet and an outlet of the inner flow path opened at both ends of the heater case and communicating with the internal flow path; and a heater inserted into the heater accommodating part to heat the working fluid in the internal flow path, wherein at least one heat transfer fin is provided in the internal flow path to increase heat transfer from the heater to the working fluid. It is formed to protrude toward the inside.

The at least one heat transfer fin is formed to protrude from an inner surface of the heater case that partitions the inner passage and the heater accommodating part.

The at least one heat transfer fin is disposed between both ends of the heat pipe inserted into the heater case through the inlet and the outlet.

The at least one heat transfer fin is formed to extend in a lengthwise direction of the heater case.

The at least one heat transfer fin may be formed by extrusion molding of the heater case.

The internal flow path may be divided into upper and lower portions based on a horizontal plane passing through the center, and the at least one heat transfer fin may be formed below the inner flow path.

The heat pipe includes a first heat pipe and a second heat pipe respectively disposed on the front and rear surfaces of the evaporator, and the internal flow path includes a first portion accommodating both ends of the first heat pipe, the second heat pipe a second portion for accommodating both ends of the , and a communication portion for mutually communicating the first portion and the second portion, wherein the at least one heat transfer fin may be formed to protrude from the first and second portions, respectively .

The at least one heat transfer fin provided in the first portion protrudes toward the center of the first portion, and the at least one heat transfer fin provided in the second portion protrudes toward the center of the second portion. can be

The at least one heat transfer fin protruding from each of the first and second parts may have a length of 1/4 or more and 3/4 or less of a distance to the center of the first and second parts.

The at least one heat transfer fin may include a first heat transfer fin and a second heat transfer fin spaced apart from each other in the first or second portion; and a third heat transfer fin disposed between the first and second heat transfer fins and having a shorter length than the first and second heat transfer fins.

The at least one heat transfer fin may also protrude from the communication portion.

A first object of the present invention, a heater case formed through the internal flow path and the heater receiving portion is not in communication with each other; a heat pipe having both ends inserted into the heater case through an inlet and an outlet of the inner flow path opened at both ends of the heater case and communicating with the internal flow path; and a heater inserted into the heater accommodating part to heat the working fluid in the internal flow path, wherein a plurality of grooves are formed in the internal flow path along the circumference to increase heat transfer from the heater to the working fluid. It can also be achieved by means of a device.

The heat transfer fin and the groove may be combined in the inner flow path.

For example, the at least one heat transfer fin may protrude long between the groove and the groove toward the inside of the inner flow path.

A hole extending parallel to the inner flow path and opened at both ends of the heater case may be formed around the inner flow path.

The hole may be positioned between the inner flow path and a corner of the heater case.

In order to achieve the second object of the present invention, the defrosting apparatus of the present invention includes: a heater case through which an internal flow path and a heater accommodating part are not communicated with each other; a heat pipe having both ends inserted into the heater case through an inlet and an outlet of the inner flow path opened at both ends of the heater case and communicating with the internal flow path; and a heater inserted into the heater accommodating part to heat the working fluid in the inner flow path, wherein bending grooves for pressing the heater accommodating part are formed on both sides of the heater case to extend along the longitudinal direction of the heater case. .

When the heater case is bent inward by the bending groove, the heater is in close contact with the inner surface of the heater accommodating part.

The bending groove has a notch shape that decreases in width toward the heater accommodating part.

A cross section of the bending groove may have a sharp shape or a rounded shape.

The bending groove may be formed at a point corresponding to 1/2 the height of the heater accommodating part.

The effects of the present invention obtained through the above-described solution are as follows.

First, since at least one heat transfer fin protrudes toward the inside of the internal flow path, the convective heat transfer coefficient of the heater case is increased compared to the structure in which the heat transfer fin is not formed, thereby improving the heat transfer efficiency from the heater to the working fluid.

In addition, when grooves are repeatedly formed along the periphery of the inner flow path of the heater case, the heating area of the working fluid increases, thereby increasing the working pressure of the working fluid, thereby stabilizing the circulation of the working fluid and improving the reliability of defrosting. can be done

Second, since the heater case is bent inward by the bending grooves formed on both sides of the heater case, the heater accommodated in the heater accommodating part may be firmly in close contact with the inner surface of the heater accommodating part. As a result, the contact area between the heater and the heater case is increased, so that heat transfer efficiency from the heater to the working fluid can be improved.

In addition, since the pressing of the heater accommodating part is performed in an intended shape by the bending groove, assembly defects may be reduced.

1 is a longitudinal cross-sectional view schematically showing the configuration of a refrigerator according to an embodiment of the present invention.
2 and 3 are a front view and a perspective view showing an example of a defrosting device applied to the refrigerator of FIG. 1 .
Figure 4 is a conceptual diagram showing a first embodiment of the heating unit shown in Figure 3;
5 is an exploded perspective view of the heating unit shown in FIG.
Fig. 6 is a cross-sectional view taken along line AA of the heater case shown in Fig. 4;
Fig. 7 is a cross-sectional view taken along line BB of the heater case shown in Fig. 4;
8 is a conceptual view illustrating a connection structure between the heater case and the heat pipe shown in FIG. 4 .
Fig. 9 is a sectional view taken along line CC of the heating unit shown in Fig. 8;
10 is an exploded perspective view illustrating an example of the heater shown in FIG. 5;
11 is a graph showing resistance-temperature characteristics of the PTC thermistor shown in FIG. 10;
12 is a graph showing current-voltage characteristics of the PTC thermistor shown in FIG. 10;
13 and 14 are conceptual views for explaining the circulation of the working fluid before and after the operation of the heater.
15 is a conceptual view showing a second embodiment of the heating unit shown in FIG.
16 is a conceptual view showing a third embodiment of the heating unit shown in FIG.
17 is a conceptual diagram showing a fourth embodiment of the heating unit shown in FIG.
18 is a conceptual view showing a fifth embodiment of the heating unit shown in FIG.
19 and 20 are a front view and a perspective view illustrating another example of a defrosting device applied to the refrigerator of FIG. 1 .

Hereinafter, a defrosting apparatus according to the present invention will be described in more detail with reference to the drawings.

In the present specification, the same and similar reference numerals are given to the same and similar components even in different embodiments, and a redundant description thereof will be omitted.

In addition, a structure applied to one embodiment may be equally applied to another embodiment as long as there is no structural and functional contradiction in the different embodiments.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

In describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted.

The accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed in the present specification is not limited by the accompanying drawings, and all changes and equivalents included in the spirit and scope of the present invention It should be understood to include water or substitutes.

1 is a longitudinal cross-sectional view schematically showing the configuration of a refrigerator 100 according to an embodiment of the present invention.

The refrigerator 100 is a device for storing food stored therein at a low temperature using cold air generated by a refrigeration cycle in which the process of compression-condensation-expansion-evaporation is continuously performed.

As shown, the refrigerator body 110 has a storage space for storing food therein. The storage space may be separated by a partition wall 111 , and may be divided into a refrigerating compartment 112 and a freezing compartment 113 according to a set temperature.

Although the present embodiment shows a top mount type refrigerator in which the freezing compartment 113 is disposed above the refrigerating compartment 112 , the present invention is not limited thereto. The present invention can also be applied to a side by side type refrigerator in which a refrigerating compartment and a freezing compartment are arranged left and right, a bottom freezer type refrigerator in which a refrigerating compartment is provided at an upper portion and a freezer compartment is provided at a lower portion, etc. can

A door is connected to the refrigerator body 110 to open and close the front opening of the refrigerator body 110 . In this figure, it is shown that the refrigerating compartment door 114 and the freezing compartment door 115 are configured to open and close the front portions of the refrigerating compartment 112 and the freezing compartment 113, respectively. The door may be variously configured as a rotatable door rotatably connected to the refrigerator main body 110 , a drawer-type door slidably connected to the refrigerator main body 110 , and the like.

The refrigerator main body 110 is provided with at least one storage unit (180, for example, the shelf 181, the tray 182, the basket 183, etc.) for efficient use of the internal storage space. For example, the shelf 181 and the tray 182 may be installed inside the refrigerator body 110 , and the basket 183 may be installed inside the door 114 connected to the refrigerator body 110 .

On the other hand, a cooling chamber 116 provided with an evaporator 130 and a blowing fan 140 is provided on the rear side of the freezing chamber 113 . A refrigerating compartment return duct 111a and a freezing compartment return duct 111b are formed in the partition wall 111 to allow air from the refrigerating compartment 112 and the freezing compartment 113 to be sucked into and returned to the cooling compartment 116 side. In addition, a cold air duct 150 communicating with the freezing chamber 113 and having a plurality of cold air outlets 150a on the front side is installed on the rear side of the refrigerating chamber 112 .

A machine room 117 is provided on the lower rear side of the refrigerator body 110 , and a compressor 160 and a condenser (not shown) are provided inside the machine room 117 .

On the other hand, the air in the refrigerating compartment 112 and the freezing compartment 113 is supplied to the cooling chamber ( 116), heat exchange with the evaporator 130 is performed, and the process of being discharged to the refrigerating chamber 112 and the freezing chamber 113 through the cold air outlet 150a of the cold air duct 150 is repeatedly performed. At this time, frost is formed on the surface of the evaporator 130 by a temperature difference between the recirculating air re-introduced through the refrigerating compartment return duct 111a and the freezing compartment return duct 111b.

To remove such frost, a defrosting device 170 is provided in the evaporator 130 , and the water removed by the defrosting device 170 , that is, the defrosting water, passes through the defrost water discharge pipe 118 at the lower part of the refrigerator body 110 . It is collected in the side defrost water receiver (not shown).

Hereinafter, the defrosting device 170 will be described in more detail.

2 and 3 are front and perspective views showing an example of a defrosting device 170 applied to the refrigerator 100 of FIG. 1 .

2 and 3 , the evaporator 130 includes a cooling pipe 131 (a cooling pipe), a plurality of cooling fins 132 , and a support 133 .

The cooling tube 131 is repeatedly bent in a zigzag shape to form a plurality of steps, columns, and a refrigerant is filled therein. The cooling tube 131 may be formed of an aluminum material.

The cooling pipe 131 may be composed of a combination of a horizontal pipe part and a bending pipe part. The horizontal pipe part is arranged horizontally with each other up and down to form a plurality of stages, and the horizontal pipe part of each stage is configured to pass through the cooling fins 132 . The bending pipe part is configured to connect the end of the upper horizontal pipe part and the end of the lower horizontal pipe part, respectively, to communicate the inside with each other.

The cooling pipe 131 is supported by passing through the supports 133 respectively provided on the left and right sides of the evaporator 130 . At this time, the bending pipe part of the cooling pipe 131 is configured to connect the end of the upper horizontal pipe part and the end of the lower horizontal pipe part from the outside of the support 133 .

Referring to FIG. 3 , in this embodiment, the first cooling tube 131 ′ and the second cooling tube 131 ″ are respectively disposed on the front and rear portions of the evaporator 130 to form two rows. For reference, in FIG. 2, the front first cooling tube 131' and the rear second cooling tube 131" are formed in the same shape as each other, and the second cooling tube 131" is the first cooling tube. (131') obscured.

However, the present invention is not limited thereto. The front first cooling tube 131 ′ and the rear second cooling tube 131 ″ may be formed in different shapes. On the other hand, the cooling tubes 131 may be formed in a single row.

A plurality of cooling fins 132 are disposed in the cooling pipe 131 to be spaced apart from each other at predetermined intervals along the extending direction of the cooling pipe 131 . The cooling fin 132 may be formed of a flat body made of an aluminum material, and the cooling tube 131 may be expanded while being inserted into the insertion hole of the cooling fin 132 to be firmly inserted into the insertion hole.

The plurality of supports 133 are provided on both left and right sides of the evaporator 130 , respectively, and are configured to support the cooling pipe 131 that extends vertically along the vertical direction. The support 133 is formed with an insertion groove or insertion hole into which a heat pipe 172, which will be described later, can be inserted and fixed.

The defrosting device 170 is installed in the evaporator 130 , and is configured to remove frost generated in the evaporator 130 . The defrosting device 170 includes a heating unit 171 and a heat pipe 172 (heat pipe).

The heating unit 171 is disposed under the evaporator 130 and is electrically connected to a control unit (not shown) to generate heat when receiving a driving signal from the control unit.

The control unit may be configured to apply a driving signal to the heating unit 171 at every preset time interval. As an example, the control unit stops (OFF) the operation of the compressor (160) and operates (ON) the power supply unit (not shown) when a predetermined time elapses after the compressor 160 constituting the refrigeration cycle is operated, Power may be supplied to the heater 171b (refer to FIG. 4 ).

The control of the control unit is not limited only to time control. The controller may be configured to apply a driving signal to the heating unit 171 when the detected temperature of the cooling chamber 116 is lowered to a preset temperature or less.

The heat pipe 172 is connected to the heating unit 171 to form a closed-loop flow path through which a working fluid (F) can circulate together with the heating unit 171 . The heat pipe 172 may be formed of an aluminum material.

The bottom pipe 172 is at least partially adjacent to the cooling pipe 131 so as to radiate heat to the cooling pipe 131 of the evaporator 130 by the high-temperature working fluid F that is heated and transferred by the heating unit 171 . are placed As the working fluid F, a refrigerant (eg, R-134a, R-600a, etc.) that exists in a liquid phase under the refrigeration condition of the refrigerator 100 but changes to a gas phase when heated and serves to transport heat. ) can be used.

The heat pipe 172 may include a first heat pipe 172 ′ and a second heat pipe 172 ″ respectively disposed on the front and rear surfaces of the evaporator 130 . In this embodiment, the first heat It is shown that the pipe 172' is disposed in front of the first cooling pipe 131', and the second heat pipe 172" is disposed in the rear of the second cooling pipe 131", forming two rows. have.

The heat pipe 172 may be configured to be accommodated between the plurality of cooling fins 132 fixed to each end of the cooling pipe 131 . According to the structure, the heat pipe 172 is disposed between each end of the cooling pipe 131 . In this case, the heat pipe 172 may be configured to contact the cooling fins 132 .

However, the present invention is not limited thereto. For example, the heat pipe 172 may be installed to pass through the plurality of cooling fins 132 . That is, the heat pipe 172 may be expanded while being inserted into the insertion hole of the cooling fin 132 to be firmly inserted into the insertion hole. According to the structure, the heat pipe 172 is disposed to correspond to the cooling pipe 131 .

4 is a conceptual diagram illustrating a first embodiment of the heating unit 171 shown in FIG. 3 , and FIG. 5 is an exploded perspective view of the heating unit 171 shown in FIG. 4 .

Looking at the heating unit 171 in detail with reference to the drawings, the heating unit 171 includes a heater case 171a and a heater 171b.

The heater case 171a is formed as a single body in which an outlet 171a1' and an inlet 171a1" are formed at both ends in the longitudinal direction. Inside the heater case 171a, an outlet 171a1' from an inlet 171a1" An internal flow path 171a1 extending toward it is formed. That is, the internal flow path 171a1 extends along the longitudinal direction of the heater case 171a and is opened at both ends of the heater case 171a to form an outlet 171a1 ′ and an inlet 171a1″, respectively.

The heater case 171a connects both ends of the heat pipe 172 to form a closed-loop circulation path through which the working fluid F can circulate together with the heat pipe 172 . That is, both ends of the heat pipe 172 are inserted into the heater case 171a through the outlet 171a1 ′ and the inlet 171a1″ to communicate with the internal flow path 171a1 .

Specifically, one end (in the drawing, the front end of the heater case 171a) of the heater case 171a is formed with an outlet 171a1' into which the one ends 172c', 172c" of the heat pipe 172 are inserted. The working fluid F in the internal flow path 171a1 heated by the heater 171b is discharged to one end 172c', 172c" of the heat pipe 172 inserted into the outlet 171a1'.

An inlet 171a1" into which the other ends 172d' and 172d" of the heat pipe 172 are inserted is formed at the other end of the heater case 171a (in the drawing, the rear end of the heater case 171a). The working fluid F condensed while passing through the heat pipe 172 is recovered to the internal flow path 171a1 through the other ends 172d' and 172d" of the heat pipe inserted into the inlet 171a1".

A heater accommodating part 171a2 into which the heater 171b is inserted is formed in the heater case 171a. The heater accommodating part 171a2 is formed to pass through the heater case 171a while not communicating with the internal flow path 171a1. The heater accommodating part 171a2 may extend in parallel to the internal flow path 171a and may have an open shape at both ends of the heater case 171a. In this figure, it is shown that the heater accommodating part 171a2 is formed under the internal flow path 171a.

As such, the structure in which the heater accommodating part 171a2 in the form of an insertion hole is formed in the heater case 171a makes it easy to mount the heater 171b, and a separate adhesive for attaching the heater 171b to the heater case 171a. It has the advantage that it is not necessary.

The heater case 171a may be formed to have an outer shape of a rectangular pole shape. Also, the heater case 171a may be formed of a metal material (eg, aluminum material).

The heater case 171a may be formed by extrusion molding. In this case, the internal flow path 171a1 and the heater accommodating part 171a2 are formed to extend along the extrusion molding direction, that is, the longitudinal direction of the heater case 171a. Also, in this case, the inlet 171a1" and the outlet 171a1' have the same size. Accordingly, the inlet 171a1" and the outlet 171a1' of the heater case 171a are disposed to face each other, and the inlet Inlet portions 172c' and 172c" and return portions 172d' and 172d" of the heat pipe 172 respectively inserted into the 171a1" and the outlet 171a1' are also disposed to face each other.

The heater case 171a may be disposed on one side of the evaporator 130 where the accumulator 134 is located, the other side opposite to that, or any position between the one side and the other side.

The heater case 171a may be disposed adjacent to the lowest end of the cooling pipe 131 . For example, the heater case 171a may be disposed at the same height as the lowest end of the cooling pipe 131 or may be disposed at a position lower than the lowest end of the cooling pipe 131 .

In this embodiment, the heater case 171a is at a position lower than the lowest end of the cooling pipe 131 on one side of the evaporator 130 where the accumulator 134 is located, and the evaporator 130 parallel to the cooling pipe 131 . ) in the horizontal direction (ie, left and right).

A heater 171b for heating the working fluid F in the internal flow path 171a1 is mounted in the heater accommodating part 171a2. The heater 171b is formed to generate heat when power is supplied, and the working fluid F in the internal flow path 171a1 is heated to a high temperature by receiving heat by the heater 171b that generates heat.

The heater 171b may have a form that is elongated along the extension direction of the heater receiving part 171a2. The heater 171b may have a flat plate shape having a predetermined thickness.

In this embodiment, it is shown that the heater accommodating part 171a2 is formed below the internal flow path 171a. As such, the structure in which the heater 171b is disposed under the heater case 171a is advantageous in allowing the heated working fluid F to have an upward driving force.

In a state in which the heater 171b is inserted into the heater accommodating part 171a2, one surface of the heater case 171a defining the heater accommodating part 171a2 (in this figure, the bottom surface 171a' of the heater case 171a) is pressed by a pressing member (not shown). The pressurization is performed in a direction from the heater accommodating part 171a2 toward the internal flow path 171a1.

By the pressure, the thickness of the heater accommodating part 171a2 is reduced, and the heater 171b is in close contact with the inner surface of the heater accommodating part 171a2. As shown, the heater 171b is in close contact with the upper inner surface and the lower inner surface of the heater accommodating portion (171a2).

During the pressurization, a bending groove 171a5 is formed in the heater case 171a so that the heater case 171a (strictly, the portion where the heater receiving part 171a2 is formed) can be crushed into a predetermined shape. The bending groove 171a5 has a shape recessed inward from the outer surface of the heater case 171a toward the heater accommodating part 171a2.

In this figure, it is shown that the bending grooves 171a5 are formed on both left and right sides of the heater case 171a defining both left and right sides of the heater accommodating part 171a2. The bending groove 171a5 is formed to extend along the longitudinal direction of the heater case 171a. The bending groove 171a5 may be formed at a point corresponding to 1/2 the height of the heater accommodating part 171a2.

The bending groove 171a5 may have a notch shape that decreases in width toward the inner side, that is, toward the heater receiving part 171a2. A cross section of the bending groove 171a5 may have a sharp shape or a rounded shape as shown.

When the bottom surface 171a' of the heater case 171a is pressed by the pressing member, the left and right side surfaces of the heater case 171a are bent inward with the bending groove 171a5 as the center. During the bending process, the heater case 171a is crushed, and the height of the heater accommodating part 171a2 is reduced.

When the height of the heater accommodating part 171a2 is reduced to a certain level, the heater 171b accommodated in the heater accommodating part 171a2 is pressed by the upper inner surface and the lower inner surface of the heater accommodating part 171a2 and is firmly fixed. . Accordingly, the heater 171b does not fall out of the heater accommodating part 171a2 without a separate fixing means.

The degree of pressurization may vary depending on the thickness of the heater 171b. That is, pressurization may be performed so that the height of the heater accommodating part 171a2 is reduced to correspond to the thickness of the heater 171b.

With the above structure, the heater 171b may be firmly fixed in the heater accommodating part 171a2. In addition, since the heater 171b is in close contact with the inner surface of the upper side of the heater accommodating part 171a2 dividing the internal flow path 171a1 and the heater accommodating part 171a2, the heat generated by the heater 171b is transferred to the internal flow path 171a1. It is delivered more to the furnace and can be used to heat the working fluid (F).

In a state in which the heater 171b is mounted (accommodated and fixed) in the heater accommodating part 171a2 , the heater accommodating part 171a2 may be filled with a sealing member 171a4 to seal the heater 171b. The sealing member 171a4 is filled in an empty space where the heater 171b is not disposed.

As shown, the sealing member 171a4 may be filled in a gap between the left and right inner surfaces of the heater accommodating part 171a2 and the left and right both sides of the heater 171b. In addition, the sealing member 171a4 may be disposed to cover the front and rear surfaces of the heater 171b.

Silicone, urethane, epoxy, etc. may be used as the sealing member 171a4. For example, the sealing structure of the heater 171b may be completed through a curing process after liquid epoxy is filled in the empty space.

Operation and stopping of the heater 171b may be controlled by time, temperature conditions, and the like. For example, the operation of the heater 171b may be controlled by a time condition, and the stopping of the heater 171b may be controlled by a temperature condition.

Specifically, when a predetermined time elapses after the evaporator 130 and the compressor 160 constituting the refrigeration cycle are operated, the controller may stop (OFF) the operation of the compressor 160 and supply power to the heater 171b. . Accordingly, the heater 171b receives power to generate heat.

When the temperature sensed by the defrost sensor 135, which will be described later, reaches a preset defrost end temperature, the controller may cut off the power supplied to the heater 171b. Since power is not supplied to the heater 171b, active heating of the heater 171b is stopped, and the temperature is gradually decreased.

In the previously invented defrosting apparatus, a fuse was used to prevent overheating of the heater. However, in the defrosting apparatus 170 of the present invention, a heater 171b having a characteristic that the current is suppressed and no longer heats up due to the rapid increase in resistance above a preset temperature is used. That is, the heater 171b itself has a function of preventing overheating. This will be described in detail later.

A defrost sensor 135 for detecting a temperature for defrosting is provided in the evaporator 130 or the cooling chamber 116 in which the evaporator 130 is disposed. The defrost sensor 135 is installed at a position suitable to represent the temperature of the evaporator 130 , and for this purpose, the defrost sensor 135 is preferably located in a portion that is less affected by the temperature rise by the defrost device 170 . do.

In this embodiment, the defrost sensor 135 is exemplified mounted on the upper end of the support (133). When the heating unit 171 is disposed adjacent to one side support 133 , the defrost sensor 135 may be mounted on the other side support 133 farther away from the heating unit 171 .

Alternatively, the defrost sensor 135 may be mounted on the inlet side of the cooling pipe 131 . The inlet side of the cooling pipe 131 is a portion having the lowest temperature in the evaporator 130 , and is a portion less affected by a temperature increase by the defrosting device 170 , and is another position representing the temperature of the evaporator 130 . is suitable as

When the temperature sensed by the defrost sensor 135 reaches a preset defrost end temperature, the controller may cut off the power supplied to the heater 171b. Since power is not supplied to the heater 171b, active heating of the heater 171b is stopped, and the temperature is gradually decreased.

Meanwhile, as the working fluid F filled in the internal flow path 171a1 is heated to a high temperature by the heater 171b, the working fluid F flows with a directionality due to the pressure difference.

Specifically, the high-temperature working fluid F heated by the heater 171b and discharged to the outlet 171a1 ′ flows into the heat pipe 172 and moves along the heat pipe 172 to cool the evaporator 130 . Heat is transferred to the tube 131 . The working fluid F is gradually cooled through this heat exchange process and introduced into the inlet 171a1". The cooled working fluid F is reheated by the heater 171b and then discharged back to the outlet 171a1'. The above process is repeated, and the cooling tube 131 is defrosted by this circulation method.

Referring back to FIGS. 2 and 3 , at least a portion of the heat pipe 172 is disposed adjacent to the cooling pipe 131 of the evaporator 130 , and is heated and transported by the heating unit 171 . It is configured to remove the frost by transferring heat to the cooling pipe 131 of the evaporator 130 by (F).

The heat pipe 172 may have a repeatedly bent shape (zigzag shape) like the cooling pipe 131 . To this end, the heat pipe 172 includes an extension portion 172a and a heat dissipation portion 172b.

The extension 172a forms a flow path for transferring the working fluid F heated by the heating unit 171 to the upper side of the evaporator 130 . The extension portion 172a is connected to the outlet 171a1 ′ of the heater case 171a provided at the lower portion of the evaporator 130 and the heat dissipation portion 172b provided at the upper portion of the evaporator 130 .

The extension portion 172a includes a vertical extension portion extending upwardly of the evaporator 130 . The vertical extension portion extends to the upper portion of the evaporator 130 while being spaced apart from the support 133 on the outside of the support 133 provided on one side of the evaporator 130 .

On the other hand, depending on the installation position of the heating unit 171, the extension (172a) may further include a horizontal extension. For example, when the heating unit 171 is provided at a position spaced apart from the vertical extension, a horizontal extension for connecting the heating unit 171 and the vertical extension may be additionally provided.

When the horizontal extension is connected to the heating unit 171 to extend long, the high-temperature working fluid F passes through the lower part of the evaporator 130, so that the evaporator 130 lower cooling pipe 131 is defrosted. It has the advantage of being able to do it smoothly.

The heat dissipation part 172b is connected to the extension part 172a extending to the upper part of the evaporator 130 and extends along the cooling pipe 131 of the evaporator 130 in a zigzag shape. The heat dissipation unit 172b is composed of a combination of a plurality of horizontal pipes 172b ′ forming a step in the upper and lower directions and a connection pipe 172b″ formed in a bent U-tube shape to connect them in a zigzag shape.

The extension part 172a or the heat dissipation part 172b may extend to a position adjacent to the accumulator 134 in order to remove the frost accumulated on the accumulator 134 .

As shown, when the vertical extension portion is disposed on one side of the evaporator 130 where the accumulator 134 is located, the vertical extension portion extends upward to a position adjacent to the accumulator 134, and then the cooling tube 131 is installed. It may be configured to be bent and extended downward toward the heat dissipation unit 172b.

On the other hand, when the vertical extension part is disposed on the other side opposite to the one side, the heat dissipation part 172b is connected to the vertical extension part and extends horizontally, and then extends upward toward the accumulator 134 and then again the cooling pipe ( 131) may be extended downward.

In the heat pipe 172, one end inserted into the inside of the heater case 171a through the outlet 171a1' constitutes the inlets 172c', 172c" through which the high-temperature working fluid F flows, and the inlet The other end inserted into the inside of the heater case 171a through (171a1") constitutes the return parts 172d' and 172d" from which the cooled working fluid F is recovered.

In the present embodiment, the working fluid F heated by the heater 171b flows into the inlets 172c' and 172c" and is transferred to the upper part of the evaporator 130 through the extension part 172a, and then heat dissipation. After performing defrosting by transferring heat to the cooling tube 131 while flowing along the portion 172b, it is returned to the heater case 171a through the return portions 172d' and 172d", and again by the heater 171b. It is reheated to form a circulation passage through which the heat pipe 172 flows.

In a structure in which the heat pipe 172 is composed of first and second heat pipes 172' and 172" forming two rows, the first and second heat pipes 172' and 172" are connected to the internal flow path 171a1. of the outlet (171a1') and the inlet (171a1") are respectively connected.

The internal flow path 171a1 may be formed to accommodate the first and second heat pipes 172' and 172" at the same time. To this end, the internal flow path 171a1 includes the first and second heat pipes 172' and 172". ") has one outlet 171a1' and one inlet 171a1" into which it is inserted.

As shown, the outlet (171a1') and the inlet (171a1") may have a long hole shape. The outlet (171a1') and the inlet (171a1") are first and second heat pipes 172' and 172". It may have a shape corresponding to a part of the outer shape of

As such, when the first and second heat pipes 172' and 172" are inserted into one outlet 171a1' and one inlet 171a1" at the same time, the heater case 171a and the first and There is an advantage that the welding point between the second heat pipes 172' and 172" can be reduced. This will be described in detail later.

Meanwhile, by the connection structure, the gaseous working fluid F heated by the heating unit 171 is discharged to the first and second heat pipes 172' and 172" through the outlets 171a1', respectively. One end of the first and second heat pipes 172' and 172" inserted into the inside of the heater case 171a through the outlet 171a1' is functional (high temperature operation heated by the heater 171b). The portion through which the liquid (F) flows] can be understood as the first and second inflow portions 172c' and 172c". The first and second inflow portions 172c', 172c" are arranged in parallel, Each is inserted into a single outlet (171a1') having a shape.

In addition, the working fluid F in a liquid state cooled while moving the first and second heat pipes 172' and 172" flows into the inside of the heater case 171a through the inlet 171a1". The other ends of the first and second heat pipes 172' and 172" inserted into the inside of the heater case 171a through the inlet 171a1" are functionally (cooling while moving each heat pipe 172). The portion in which the working fluid F in the liquid state is recovered] may be understood as first and second return parts 172d' and 172d". The first and second return parts 172d' and 172d" are parallel to each other. It is arranged to be inserted into each of the single inlet (171a1") having a long hole shape.

For reference, in this embodiment, the heat pipe 172 is shown to be composed of first and second heat pipes 172' and 172" forming two rows, but the present invention is not limited thereto. 172) may be formed in a single row.

The heater case 171a is provided with a working fluid injection port 171a3 for injecting the working fluid F into the internal flow path 171a1. The working fluid F injected through the working fluid injection hole 171a3 is filled in the internal flow path 171a1 of the heater case 171a, and then a predetermined amount is filled in the heat pipe 172 .

The operating fluid injection hole 171a3 penetrates one surface of the heater case 171a and is formed to communicate with the internal flow path 171a1. In this figure, it is shown that the operating fluid injection hole 171a3 is formed through one side of the heater case 171a toward the inside, and is configured to communicate with the internal flow path 171a1.

In order to inject the working fluid F, the working fluid injection pipe 173 is connected to the working fluid inlet 171a3. After the working fluid injection pipe 173 is inserted into the working fluid inlet 171a3, it may be fixed to the heater case 171a by welding to fill the gap between the working fluid inlet 171a3 and the working fluid injection pipe 173. . After the working fluid F is filled through the working fluid injection pipe 173 , the working fluid injection pipe 173 is sealed.

6 is a cross-sectional view of the heater case 171a shown in FIG. 4 taken along line A-A, FIG. 7 is a cross-sectional view of the heater case 171a shown in FIG. 4 taken along line B-B, and FIG. 8 is shown in FIG. It is a conceptual diagram showing a connection structure between the heated heater case 171a and the heat pipe 172 .

6 to 8, the inlet (172c', 172c") of the heat pipe 172 is inserted into the internal flow path 171a1 formed in the inside of the heater case 171a through the outlet 171a1', The return parts 172d' and 172d" of the heat pipe 172 are inserted into the internal flow path 171a1 through the inlet 171a1". The inlets 172c' and 172c" of the heat pipe 172 and the return The portions 172d′ and 172d″ may be disposed to face each other with the internal flow path 171a1 interposed therebetween.

A gap between the heat pipe 172 and the heater case 171a may be filled by welding. Specifically, the first welded portion 171m is formed to fill a gap between the inlet portions 172c' and 172c" and the outlet 171a1', and the second welded portion 171n is formed with the return portions 172d' and 172d"). It is formed to fill the gap between the inlets (171a1").

As shown, when the first and second inlet portions 172c' and 172c" are inserted into the outlet 171a1' in a state in which they are arranged in parallel, the first welded portion 171m is the first inlet portion 172c' ) and the outlet (171a1') and the gap between the second inlet (172c") and the outlet (171a1') is formed to fill together. Accordingly, the first and second inlets 172c' and 172c" can be fixed to the heater case 171a through one welding.

Similarly, when the first and second return portions 172d' and 172d" are inserted into the inlet 171a1" in a state in which they are arranged in parallel, the second welded portion 171n is connected to the first return portion 172d' and the inlet. It is formed to fill the gap between (171a1") and the gap between the second return part 172d" and the inlet 171a1". Therefore, the first and second return parts 172d' and 172d" through one welding. ) can be fixed to the heater case (171a).

In this way, a gap between the first and second inlet portions 172c' and 172c" and the outlet 171a1' formed in parallel is welded at once, and the first and second return portions 172d' and 172d" formed in parallel are welded together. ) and the inlet (171a1") by welding the gap at once, it is possible to further reduce the number of welding points, thereby reducing the production cost.

On the other hand, the operating fluid inlet (171a3) is formed to communicate with the internal flow path (171a1) between the first and second inlet (172c', 172c") and the first and second return parts (172d', 172d"). . In addition, in a state in which the working fluid injection pipe 173 is inserted into the working fluid injection port 171a3 , the third welding part 171p is formed to fill a gap between the operating fluid injection port 171a3 and the working fluid injection pipe 173 . .

At least one heat transfer fin 171a1d, 171a1e, and heat transfer fin is formed to protrude toward the inner passage 171a1. The heat transfer fins 171a1d and 171a1e guide heat into the inner flow path 171a1 so that heat transfer from the heater 171b to the working fluid F can be increased.

According to the above structure, not only the working fluid F in contact with the surface of the inner flow path 171a1 is heated, but also the working fluid F flowing inside the surface by the heat transfer fins 171a1d and 171a1e is heated. do. That is, more heat may be transferred to the working fluid F flowing through the internal flow path 171a1. Accordingly, the working fluid F is quickly heated, so that the defrosting device 170 can perform defrosting more quickly.

The heat transfer fins 171a1d and 171a1e are disposed between both ends of the heat pipe 172 inserted into the heater case 171a, that is, the inlets 172c' and 172c" and the return parts 172d' and 172d". . That is, the heat transfer fins 171a1d and 171a1e are not formed at both ends of the internal flow path 171a1 in which the inflow parts 172c' and 172c" and the return parts 172d' and 172d" are accommodated.

When the heater case 171a is formed by extrusion molding, the heat transfer fins 171a1d and 171a1e are formed to extend along the extrusion molding direction, that is, the longitudinal direction of the heater case 171a. After extrusion, the heat transfer fins 171a1d and 171a1e formed at both ends of the internal flow path 171a1 for insertion of the inlet parts 172c' and 172c" and the return parts 172d' and 172d" are removed, the final heater A case 171a is manufactured.

Referring to FIG. 6 , the internal flow path 171a1 may be divided into an upper portion and a lower portion based on a horizontal plane P passing through the center. As shown, in the structure in which the heater receiving part 171a2 is positioned under the internal flow path 171a1, the heat transfer fins 171a1d and 171a1e are preferably formed below the internal flow path 171a1. According to the above structure, an efficient heat transfer structure in which the heat generated by the heater 171b is guided to the inside of the internal flow path 171a1 may be implemented.

The internal flow path 171a1 includes a first portion 171a1a accommodating both ends of the first heat pipe 172 ′, a second portion 171a1b accommodating both ends of the second heat pipe 172 ″, and a first portion (171a1a) and the second portion (171a1b) may include a communication portion (171a1c) to communicate with each other.The first portion (171a1a) and the second portion (171a1b) are first and second heat pipes 172', 172") has a shape corresponding to a portion of the outer shape. The operating fluid inlet (171a3) may be formed to communicate with the first or second portions (171a1a, 171a1b).

As illustrated, the heat transfer fins 171a1d and 171a1e may be formed to protrude inward from the first and second portions 171a1a and 171a1b, respectively. The heat transfer fins 171a1d formed on the first portion 171a1a and the heat transfer fins 171a1e formed on the second portion 171a1b may have a symmetrical shape with respect to the communication portion 171a1c.

The heat transfer fins 171a1d provided in the first portion 171a1a protrude toward the center of the first portion 171a1a, and the heat transfer fins 171a1e provided in the second portion 171a1b are formed in the second portion 171a1b. It may be formed to protrude toward the center of the.

The heat transfer fins 171a1d and 171a1e protruding from each of the portions 171a1a and 171a1b, respectively, preferably have a length of 1/4 or more and 3/4 or less of the distance to the center of each of the portions 171a1a and 171a1b. When the length of the heat transfer fins 171a1d and 171a1e is less than 1/4 of the distance to the center of each part 171a1a, 171a1b, heat transfer to the working fluid F flowing inside the surface of each part 171a1a, 171a1b This cannot be done enough. In addition, if the length of the heat transfer fins 171a1d and 171a1e exceeds 3/4 of the distance to the center of the respective parts 171a1a and 171a1b, the flow of the working fluid F is disturbed and defects in extrusion molding increase. do.

A plurality of heat transfer fins 171a1d1 , 171a1d2 , 171a1d3 , 171a1e1 , 171a1e2 , and 171a1e3 may be formed in each of the portions 171a1a and 171a1b . In this embodiment, the first heat transfer fins 171a1d1 and 171a1e1 and the second heat transfer fins 171a1d2 and 171a1e2 are spaced apart from each other, and the first and second heat transfer fins 171a1d1, 171a1e1, 171a1d2, and 171a1e2 are spaced apart from each other. It is shown that the third heat transfer fins 171a1d3 and 171a1e3 having a short length are provided. The first to third heat transfer fins 171a1d1 , 171a1d2 , 171a1d3 , 171a1e1 , 171a1e2 , and 171a1e3 may be formed under the internal flow path 171a1 .

9 is a cross-sectional view taken along the line C-C of the heating unit 171 shown in FIG. 8 .

As shown in FIG. 9 , the internal flow path 171a1 has an active heating part (AHP) corresponding to the portion where the heater 171b is disposed and passive heating corresponding to the portion where the heater 171b is not disposed. It is divided into parts (PHP: Passive Heating Part).

A heater 171b is disposed in a portion corresponding to the active heating unit AHP in the heater accommodating portion 171a2 (the lower side of the active heating unit AHP in the drawing), and a portion corresponding to the passive heating unit PHP [Fig. A sealing member 171a4 is disposed on the lower side of the upper passive heating unit PHP.

The active heating unit (AHP) is a portion directly heated by the heater (171b), the liquid working fluid (F) is heated in the active heating unit (AHP) is phase-changed into a high-temperature gaseous state.

The inlets 172c' and 172c" of the heat pipe 172 may be located in the active heating unit AHP, or located in front of the active heating unit AHP (based on the flow direction of the working fluid F). 9, the heater 171b exemplifies that the heater 171b is formed to extend forward past under the inlets 172c' and 172c". That is, in the present embodiment, the inlets 172c' and 172c" of the heat pipe 172 are located in the active heat generating unit AHP.

A passive heating part PHP is formed in the rear (direction opposite to the flow of the working fluid F) of the active heating part AHP. The passive heating unit (PHP) is not directly heated by the heater (171b) like the active heating unit (AHP), but is heated to a predetermined temperature level by receiving heat indirectly. Here, the passive heating unit (PHP) may only cause a predetermined temperature increase in the working fluid F in a liquid state, but does not have a high enough temperature to change the phase of the working fluid F to a gaseous state. That is, in terms of temperature, the active heating unit (AHP) forms a relatively high temperature part, and the passive heating part (PHP) forms a relatively low temperature part.

If the working fluid F is configured to be returned directly to the high-temperature active heating unit AHP, the recovered working fluid F is heated again, so that it does not return smoothly into the heater case 171a and flows backward. can occur This may interfere with the circulating flow of the working fluid F in the heat pipe 172 and cause a problem in which the heater 171b is overheated.

In order to improve this problem, the return parts 172d' and 172d" of the heat pipe 172 inserted into the inlet 171a1" communicate with the passive heating part PHP, and after moving the heat pipe 172 It is configured so that the returned working fluid F does not directly flow into the active heating unit AHP.

At least a portion of the heat transfer fins 171a1d and 171a1e are disposed in the active heat generating unit AHP to guide heat generated by the heater 171b to the inside of the surface of the internal flow path 171a1. All of the heat transfer fins 171a1d and 171a1e may be disposed within the active heat generating unit AHP, or may be disposed across the active heat generating unit AHP and the passive heat generating unit PHP as illustrated.

10 is an exploded perspective view illustrating an example of the heater 171b shown in FIG. 5 .

As described above, the heater 171b is configured such that the current is suppressed due to the rapid increase in resistance above the preset temperature so that no more heat is generated. For example, in order to ensure the safety of the defrosting device 170, the heater 171b may be configured to no longer generate heat when it reaches 280°C.

As such, the heating temperature of the heater 171b is limited by its own characteristics. Accordingly, there is an advantage in that the safety of the heater 171b can be secured without using a fuse as a safety device provided in the conventional heating unit.

Referring to FIG. 10 , the heater 171b may include first and second electrode plates 171b1 and 171b2 and a PTC thermistor (Positive Temperature Coefficient Thermistor, 171b3).

The first and second electrode plates 171b1 and 171b2 are disposed to face each other at a predetermined interval. The first and second electrode plates 171b1 and 171b2 are formed of a metal material (eg, aluminum material).

Each of the first and second electrode plates 171b1 and 171b2 is electrically connected to a power supply unit (not shown) through a lead wire 171b5. In order to connect the lead wire 171b5 to the first and second electrode plates 171b1 and 171b2, each of the first and second electrode plates 171b1 and 171b2 has a clamping part 171b1 for wrapping and fixing the lead wire 171b5. ', 171b2') may be formed.

A PTC thermistor 171b3 is interposed between the first electrode plate 171b1 and the second electrode plate 171b2. The PTC thermistor 171b3 has a characteristic that resistance increases as the temperature rises. The PTC thermistor 171b3 is formed of barium titanate-based ceramics obtained by mixing and firing barium titanate with trace amounts (0.1 to 1.5%) of oxides such as lanthanum, yttrium, bismuth, and thorium.

The PTC thermistor 171b3 has a relatively small resistance value at a low temperature, but has a characteristic that the resistance suddenly increases when a specific temperature is reached. Therefore, the current is suppressed above the specified temperature.

As such, the temperature at which the temperature-resistance characteristic of the PTC thermistor 171b3 rapidly changes is called a Curie point or a Curie temperature. The Curie point may be moved to a high temperature side or a low temperature side by adjusting the components of the PTC thermistor 171b3. Therefore, by controlling the components of the PTC thermistor 171b3, it is possible to manufacture a heater 171b that generates sufficient heat for defrosting but is limited in heat generation above a specific temperature.

The method to adjust the cue point is as follows. When some of the barium is replaced with lead, the Curie point shifts toward higher temperatures. When barium is replaced with strontium or a part of titanium is replaced with tin or zirconium, the Curie point shifts toward lower temperatures. In this way, the PTC thermistor 171b3 having appropriate heating characteristics to be used as the defrosting heater 171b can be made.

A plurality of PTC thermistors 171b3 may be provided. For example, as illustrated, two PTC thermistors 171b3 of xW (watts) may be disposed along one direction to constitute a heater 171b of 2xW (watts).

The PTC thermistor 171b3 is in close contact with the first and second electrode plates 171b1 and 171b2, respectively. A resistance paste (eg, Ag paste) may be applied to both surfaces of the PTC thermistor 171b3 contacting the first and second electrode plates 171b1 and 171b2, respectively.

Meanwhile, the heater 171b may further include an insulating film 171b4 formed to surround the first and second electrode plates 171b1 and 171b2. As shown, the insulating film 171b4 may be configured to accommodate the first and second electrode plates 171b1 and 171b2 having the PTC thermistor 171b3 interposed therebetween.

Hereinafter, the characteristics of the PTC thermistor 171b3 will be described in more detail.

11 is a graph showing resistance-temperature characteristics of the PTC thermistor 171b3 shown in FIG. 10 .

When the resistance of the PTC thermistor 171b3 according to the temperature change is measured, the resistance-temperature characteristic as shown in FIG. 11 is obtained. When the PTC thermistor 171b3 reaches the Curie point, the resistance suddenly increases rapidly.

The Curie point at which the temperature-resistance characteristic of the PTC thermistor 171b3 changes rapidly is generally at a temperature corresponding to twice the minimum resistance value (Rmin) or the resistance value (Rn) at a reference temperature (Tn, room temperature, 25°C). It is defined as the temperature corresponding to double.

In the graph, Tmin is the temperature for the minimum resistance value (Rmin), Ts is the Curie point (switching temperature) at which the resistance value rapidly increases, and Rs is the resistance value at the Curie point.

12 is a graph showing current-voltage characteristics of the PTC thermistor 171b3 shown in FIG. 10 .

When the voltage is gradually increased by applying the voltage to the PTC thermistor 171b3, the temperature rises due to self-heating as shown in FIG. When the temperature rises to exceed the Curie point, the resistance increases due to the above-described resistance-temperature characteristic, and the current decreases. Using this characteristic, the PTC thermistor 171b3 can be used as a heater 171b having a constant temperature heating function and an overcurrent protection function.

If you look at the voltage and current on a log scale, it can be seen that the electrostatic power characteristic appears in the part where the current decreases. Due to this characteristic, there is an advantage that a separate control circuit is not required for the PTC thermistor 171b3.

Due to the characteristics of the PTC thermistor 171b3 described above, the PTC thermistor 171b3 stays in the low resistance region during normal operation and plays the role of a general fixed resistance, but after exceeding the Curie point due to self-heating, the current is suppressed and further Overheating is prevented. Accordingly, problems such as shortening the life of the heater due to overheating and lowering the efficiency of the evaporator can be solved. In addition, unlike a fuse that cannot perform a function again because the internal configuration melts when the temperature exceeds a preset temperature, the heater 171b using the PTC thermistor 171b has a characteristic of preventing overheating itself, so the defrost device 170 ) has an advantage in terms of maintenance.

13 and 14 are conceptual views for explaining the circulation of the working fluid F before and after the operation of the heater 171b.

First, referring to FIG. 13 , before the heater 171b is operated, the working fluid F is in a liquid state, and is filled up to a predetermined upper end based on the lower lowest end of the heat pipe 172 . For example, in this state, the working fluid F may be filled up to the lower two stages of the heat pipe 172 .

When the heater 171b operates, the working fluid F in the heater case 171a is heated by the heater 171b. Referring to FIG. 14 , the working fluid F heated to the high temperature gaseous state F1 flows into the inlets 172c ′ and 172c″ of the heat pipe 172 and flows through the heat pipe 172 , the cooling pipe The heat is radiated to 131. The working fluid F loses heat in the heat dissipation process and flows in a state F2 in which liquid and gas coexist, and finally in a liquid state F3 of the heat pipe 172. It is introduced into the heating unit 171 through the return parts (172d', 172d"). The working fluid F flowing into the heating unit 171 is reheated by the heater 171b, and the flow as described above is repeated (circulated), and in this process, heat is transferred to the evaporator 130 and the evaporator ( 130) will be removed.

As such, the working fluid F flows by the pressure difference generated by the heating unit 171 and rapidly circulates through the heat pipe 172 , so that the entire section of the heat pipe 172 reaches a stable operating temperature within a short time. can be, and thus defrosting can be made quickly.

On the other hand, the working fluid F flowing into the inlets 172c' and 172c" is a high-temperature gaseous state F1 and has the highest temperature during the circulation process of the heat pipe 172. Therefore, such a high-temperature gaseous state By using the convection of heat by the working fluid F placed in (F1), it is possible to more efficiently remove the frost accumulated on the evaporator 130 .

For example, the inlets 172c' and 172c" may be disposed at a position relatively lower than the lowest end of the cooling pipe 131 provided in the evaporator 130 or at the same position as the lowest end. The high-temperature working fluid F flowing in through 172c', 172c") not only transfers heat near the lowest end of the cooling pipe 131, but also increases this heat to the cooling pipe 131 adjacent to the lowest end. ) can be transferred.

Meanwhile, in order for the working fluid F to circulate through the heat pipe 172 with such a phase change, the working fluid F needs to be filled in the heat pipe 172 in an appropriate amount.

As a result of the experiment, when the working fluid F is filled to less than 30% of the total internal volume of the heat pipe 172 and the heater case 171a, the temperature of the heating unit 171 rapidly increases over time. could confirm that This means that the working fluid F is insufficient relative to the total internal volume of the heat pipe 172 and the heater case 171a.

In addition, when the operating fluid F is filled in excess of 40% of the total internal volume of the heat pipe 172 and the heater case 171a, the temperature of some stages of the heat pipe 172 is stabilized at the operating temperature [40 ° C.] ~50°C (-21°C freezing condition)] was confirmed. This temperature drop is more pronounced as the heat pipe 172 approaches the return parts 172d' and 172d". This is because the operating fluid F is excessive compared to the total volume of the heat pipe 172 and the heater case 171a. It can be seen that the section in which the working fluid F flows in a liquid state increases.

When the working fluid F is filled to 30% or more and 40% or less of the total internal volume of the heat pipe 172 and the heater case 171a, the temperature of the heating unit 171 and the temperature of each stage of the heat pipe 172 It was confirmed that the temperature reached a stable operating temperature over time.

At this time, the temperature of each end of the heat pipe 172 shows a higher temperature as it approaches the inlets 172c' and 172c", and shows a lower temperature as it gets closer to the return parts 172d' and 172d". appear. As the amount of the filled working fluid F decreases, the difference between the temperature (maximum temperature) at the inlet parts 172c' and 172c" and the temperature (minimum temperature) at the return parts 172d' and 172d" also decreases. It was.

Therefore, the working fluid F is filled to 30% or more and 40% or less of the total internal volume of the heat pipe 172 and the heater case 171a, and each defrost according to the heat transfer structure, stability, etc. of the defrosting device 170 . A filling amount of the working fluid F optimized for each device 170 may be selected.

Hereinafter, other embodiments of the heating unit 171 shown in FIG. 3 will be described. For reference, in order to reduce duplication or repetition of description, only parts structurally different from those of the first embodiment will be described in the description of other embodiments. Accordingly, the description of the heater 171b of the first embodiment may be equally applied to the heaters 271b, 371b, 471b, and 571b of other embodiments to be described later.

15 is a conceptual diagram showing a second embodiment of the heating unit 171 shown in FIG.

Referring to FIG. 15 , the heat transfer fins 271a1d, 271a1e, and 271a1f may also protrude from the communication portion. That is, the heat transfer fins 271a1d, 271a1e, and 271a1f may be formed to protrude inward from the first portion 271a1a, the second portion 271a1b, and the communication portion 271a1c, respectively.

The heat transfer fins 271a1d provided in the first portion 271a1a protrude toward the center of the first portion 271a1a, and the heat transfer fins 271a1e provided in the second portion 271a1b are formed in the second portion 271a1b. The heat transfer fins 271a1f provided in the communication part 271a1c may protrude toward the center of the communication part 271a1c.

In the structure in which the heater 171b is disposed under the inner passage 171a1 as in the present embodiment, the heat transfer fins 271a1d provided in the first portion 271a1a, the second portion 271a1b, and the communication portion 271a1c. , 271a1e, 271a1f) are preferably disposed below the internal flow path 171a1 based on a horizontal plane passing through the center.

16 is a conceptual diagram showing a third embodiment of the heating unit 171 shown in FIG.

As in the previous structure, when the heater case 171a is disposed in the horizontal direction (ie, the left and right direction) of the evaporator 130 , frost may be accumulated on the upper surface of the heater case 171a. When the internal flow path 171a1 is formed just below the top surface of the heater case 171a, frost accumulated on the top surface of the heater case 171a drops the temperature of the working fluid F in the internal flow path 171a1. Therefore, it may be a factor to reduce the thermal efficiency of the heater (171b).

In order to improve this, the heating unit 371 in which the positions of the internal flow path 371a1 and the heater accommodating part 371a2 are reversed may be considered. That is, in the structure in which the heater case 371a is arranged in the horizontal direction (ie, the left-right direction) of the evaporator 330 , the heater accommodating part 371a2 is formed on the inner flow path 371a. By this arrangement, the heater accommodating part 371a2 is formed just below the upper surface of the heater case 371a. That is, the upper surface of the heater case 371a defines the heater accommodating part 371a2.

With this arrangement, the heat generated by the heater 371b is used not only to heat the working fluid F, but also to remove the frost accumulated on the heater case 371a. Accordingly, the thermal efficiency of the heater 371b may be improved.

In the above structure, it is preferable that the heat transfer fins are formed on the upper part of the internal flow path. That is, since the heat transfer fins are formed to protrude from the upper surface of the inner passage, an efficient heat transfer structure in which the heat generated by the heater 371b is guided to the inside of the inner passage 171a1 may be implemented.

17 is a conceptual diagram showing a fourth embodiment of the heating unit 171 shown in FIG.

Referring to FIG. 17 , grooves 471a1a are repeatedly formed along the circumference of the inner flow path 471a1 formed in the heater case 471a. Since the heater case 471a is formed by extrusion molding, the groove 471a1a extends along the extrusion molding direction, that is, along the longitudinal direction of the heater case 471a, like the internal flow path 471a1 and the heater accommodating part 471a2. .

As the grooves 471a1a are repeatedly formed along the circumference of the inner passage 471a1 , the heating area of the inner passage 471a1 may be increased. Accordingly, the amount of heat transferred to the working fluid F may be increased, and the circulation stabilization of the working fluid F and reliability of defrosting may be improved due to the increase in operating pressure.

In order to maximize the heat generation area of the inner passage 471a1, the radius of the groove 471a1a is preferably set as small as possible at a level that can be formed by extrusion molding. For example, the radius of the groove 471a1a may be set to 0.45 mm.

In this figure, it is shown that the groove 471a1a is continuously formed along the circumference of the inner flow path 471a1. Here, continuous means that the other groove 471a1a starts immediately when one groove 471a1a ends.

Alternatively, the grooves 471a1a may be repeatedly formed at regular intervals along the circumference of the inner flow path 471a1.

The heat transfer fins 471a1d and 471a1e are formed to protrude toward the inside of the inner flow path 471a1 between the grooves 471a1a and 471a1a. The heat transfer fins 471a1d and 471a1e are formed to protrude more than a relatively protruding portion between the groove 471a1a and the groove 471a1a (actually, the groove 471a1a is a relatively recessed portion), so that the relatively distinguished from the protruding part.

18 is a conceptual diagram showing a fifth embodiment of the heating unit 171 shown in FIG.

Referring to FIG. 18 , a hole 571a1b extending parallel to the inner passage 571a1 and opened at both ends of the heater case 571a may be formed around the inner passage 571a1 . The hole 571a1b may be positioned between the inner flow path 571a1 and the edge of the heater case 571a.

The hole 571a1b is formed to extend along the extending direction of the internal flow path 571a1 and the heater accommodating part 571a2, that is, the longitudinal direction of the heater case 571a. The hole 571a1b may be formed during extrusion molding of the heater case 571a or may be formed by drilling the extruded heater case 571a.

The hole 571a1b is formed on a path through which heat is emitted around the inner flow path 571a1 so that the emitted heat can be concentrated again in the hole 571a1b, thereby limiting the external emission of heat. The hole 571a1b may be formed in a circular shape as shown, and may be formed in a pointed shape toward the internal flow path 571a1 so that heat concentrated in the hole 571a1b can be discharged again toward the internal flow path 571a1. may be

As such, since the hole 571a1b is formed, the heat transferred to the internal flow path 571a1 is not used to heat the working fluid, but is emitted to the outside of the heater case 571a and leads to heat loss can be reduced. As a result, since the hole 571a1b is formed, more heat may be concentrated into the internal flow path 571a1.

In this figure, as in the fourth embodiment, a groove 571a1a is repeatedly formed along the circumference of the inner flow path 571a1, and the heat transfer fins 571a1d and 571a1e are formed inside the groove 571a1a and between the groove 571a1a. A structure in which a hole 571a1b is additionally formed in the heater case 571a protruding toward the inside of the flow path 571a1 is shown. However, the present invention is not necessarily limited thereto. Holes 571a1b may be additionally formed in the heater cases 171a, 271a, and 371a of the first to third embodiments.

19 and 20 are front and perspective views showing another example of the defrosting device 170 applied to the refrigerator 100 of FIG. 1 .

19 and 20 , the heating unit 671 may be disposed outside one side of the defrosting device 670 . Specifically, the heater case 671a may be located outside the support 633 provided on one side of the evaporator 630 , and may be formed to extend from the lower side of the evaporator 630 to the upper side in a vertical direction. In this case, at least a portion of the heater case 671a may be disposed between the first cooling pipe 631 ′ and the second cooling pipe 631 ″.

The heater case 671a is respectively connected to the heat pipe 672 to form a circulation flow path through which the working fluid F can circulate. To this end, an outlet and an inlet are respectively formed on the upper and lower sides of the heater case 671a. The outlet is connected to the extension portion 672a of the heat pipe 672 , and the inlet is connected to the lowest end of the heat dissipation portion 672b of the heat pipe 672 .

The heater 671b is mounted on the heater case 671a and vertically disposed in the vertical direction of the evaporator 630 . As described in the previous embodiments, the heater 671b is accommodated in the heater accommodating part 671a2 formed to penetrate the heater case 671a, and may be firmly fixed in the heater accommodating part 671a2 by pressing.

Although the figure shows that the heater accommodating part 671a2 is disposed outside the internal flow path 671a1, the present invention is not necessarily limited thereto. The heater accommodating part 671a2 may be disposed inside the inner passage 671a1 , that is, between the inner passage 671a1 and the support 633 .

The heater 671b is disposed between the inlet and the outlet so as to extend toward the outlet, so as to reheat the working fluid F recovered through the inlet. As such, the structure in which the inner flow path 671a1 extends in the vertical direction from the lower side of the evaporator 630 to the upper side is advantageous in that the working fluid F in the inner flow path 671a1 is heated to form an upward flow. , there is an advantage that the backflow of the working fluid F can be prevented.

On the other hand, the working fluid (F) is preferably filled higher than the uppermost end of the heater (671b) extending in the vertical direction inside the heater case (671a). According to such a configuration, a defrosting operation can be safely performed in a state in which the heating unit 671 is not overheated, and the continuous supply of the gaseous working fluid F to the heat pipe 672 can be made stably.

A heat transfer fin 671a1d is formed to protrude from the inner surface of the heater case 671a that divides the inner passage 671a1 and the heater accommodating part 671a2. The heat transfer fins 671a1d are formed to protrude toward the inside of the internal flow path 671a1, so that heat transfer from the heater 671b to the working fluid F can be increased.

The heat transfer fins 671a1d are disposed between both ends of the heat pipe 672 inserted into the heater case 671a, that is, between the extension part 672a and the heat radiation part 672b. That is, the heat transfer fins 671a1d are not formed at both ends of the internal flow path 671a1 in which the extension part 672a and the heat dissipation part 672b are accommodated.

At least a portion of the heat transfer fins 671a1d are disposed in the active heat generating unit AHP to guide heat generated by the heater 671b to the inside of the surface of the internal flow path 671a1. All of the heat transfer fins 671a1d may be disposed within the active heat generating unit AHP, or may be disposed across the active heat generating unit AHP and the passive heat generating unit PHP as illustrated.

Claims (15)

a heater case formed through the internal flow path and the heater accommodating part to not communicate with each other;
a heat pipe having both ends inserted into the heater case through an inlet and an outlet of the inner flow path opened at both ends of the heater case and communicating with the internal flow path; and
and a heater inserted into the heater accommodating part to heat the working fluid in the internal flow path,
At least one heat transfer fin is formed to protrude toward the inside of the inner flow path so that heat transfer from the heater to the working fluid can be increased,
The heat pipe includes a first heat pipe and a second heat pipe respectively disposed on the front part and the rear part of the evaporator,
The internal flow path includes a first part for accommodating both ends of the first heat pipe, a second part for accommodating both ends of the second heat pipe, and a communication part for communicating the first part and the second part with each other. and
The at least one heat transfer fin is a defrosting device, characterized in that each protruding from the first and second portions. According to claim 1,
The at least one heat transfer fin is disposed between both ends of the heat pipe inserted into the heater case through the inlet and the outlet. 3. The method of claim 2,
The at least one heat transfer fin is a defrosting device, characterized in that extending in a longitudinal direction of the heater case. 4. The method of claim 3,
The at least one heat transfer fin is a defrosting device, characterized in that formed by extrusion molding of the heater case. According to claim 1,
The internal flow path is divided into upper and lower parts based on a horizontal plane passing through the center,
The at least one heat transfer fin is a defrosting device, characterized in that formed under the inner flow path. delete According to claim 1,
The at least one heat transfer fin provided in the first part is formed to protrude toward the center of the first part,
The at least one heat transfer fin provided in the second portion is a defrosting device, characterized in that protruding toward the center of the second portion. 8. The method of claim 7,
The at least one heat transfer fin protruding from the first and second portions, respectively, has a length of 1/4 or more and 3/4 or less of the distance to the center of the first and second portions. . 8. The method of claim 7,
the at least one heat transfer fin,
a first heat transfer fin and a second heat transfer fin spaced apart from each other in the first or second portion; and
and a third heat transfer fin disposed between the first and second heat transfer fins, the third heat transfer fin having a shorter length than the first and second heat transfer fins. According to claim 1,
The at least one heat transfer fin is a defrosting device, characterized in that protruding from the communication portion. The method of claim 1,
A plurality of grooves are formed along the circumference of the inner flow path,
The at least one heat transfer fin is a defrosting device, characterized in that between the groove and the groove to protrude toward the inside of the inner flow path. According to claim 1,
The defrosting apparatus, characterized in that the hole extending parallel to the inner flow path is opened at both ends of the heater case is formed around the inner flow path. 13. The method of claim 12,
The hole is a defrost device, characterized in that located between the inner flow path and the edge of the heater case. According to claim 1,
Bending grooves for pressing the heater accommodating part are formed on both sides of the heater case to extend along the longitudinal direction of the heater case,
When the heater case is bent inward by the bending groove, the heater is in close contact with the inner surface of the heater accommodating part. According to claim 1,
The heater case is disposed in the left and right direction of the evaporator,
The heater accommodating part is a defrosting apparatus, characterized in that located below the inner flow path.

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