KR100547327B1 - Defrost apparatus of refrigerator - Google Patents

Abstract

The present invention has been made to solve the above problems, and relates to a defrosting apparatus of the refrigerator to be able to defrost uniformly by coupling a flexible surface heater to the outer peripheral surface of the evaporator.

Defroster of the refrigerator according to the present invention comprises an evaporator having a fin and a tube; In order to remove the surface frost layer of the evaporator, it is arranged in a predetermined form and consists of a heater wire that generates heat in accordance with the power supply, and an insulating film that is fixed to the inside of the heater wire for the insulation and protection of the heater wire and attached to both sides of the evaporator It characterized in that it comprises a surface heater.

Refrigerator, Defrost, Surface heater

Description

Defrost apparatus of refrigerator

1 is a schematic cross-sectional view of a refrigerator.

Figure 2a, 2b is a view showing a defrosting device of a conventional refrigerator.

3 is a view showing another defrosting device of a conventional refrigerator.

Figure 4 is an exploded perspective view showing a defrosting device of a refrigerator according to an embodiment of the present invention.

Figure 5 is a perspective view showing a partially coupled state of the defrosting device of the refrigerator according to the embodiment of the present invention.

6 is a cross-sectional view taken along line AA ′ of the present invention.

Figure 7 is a combined state of the defrosting device of the refrigerator according to the embodiment of the present invention.

8 is a view showing a planar heater according to another embodiment of the present invention.

9 is a view showing a planar heater according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

110 ... Evaporator 111 ... Tube

112 ... pin 113 ... tube bracket

210,310 ... Plane heater 211,311

212,312 Insulation film 220,320,420 First surface heater

230,330,430 ... 2nd floor heater 240,340,440 ... 3rd floor heater

241.Cold air inlet

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a surface heater having a defrost water drop passage and an air circulation passage in the center of the refrigerator, in particular facing the front and rear surfaces of the evaporator to defrost the evaporator of the refrigerator.

1 is a block diagram illustrating a structure of a general refrigerator. Referring to the refrigerator, when the refrigerant passing through the compressor, the condenser, and the capillary is sucked into the evaporator 1, the refrigerant is completely vaporized while passing through the evaporator 1. It takes away the heat from the surroundings and cools the surroundings.

Thereafter, the air cooled by the evaporator 1 is provided to the freezer compartment (U) and the refrigerating chamber (L), and thus the cold air having a temperature rise after cooling the inside of the refrigerator is provided in the freezer compartment (U) and the refrigerating chamber (L). Are combined in the cooling passage (3a) of the barrier (3) forming a boundary of the () and flows into the evaporator (1) side.

However, since the air introduced into the evaporator 1 is changed into hot and humid air while passing through the freezing chamber U and the refrigerating chamber L, the air is maintained at a temperature of minus 30 degrees or less. When the surface of 1) exchanges with a refrigerant of 32 degrees Celsius flowing inside the evaporator 1, the moisture in the air is instantaneously solidified to form a frost layer on the surface of the evaporator 1.

As described above, the frost layer formed on the surface of the evaporator 1 changes into hard ice as time passes and acts as a resistance element of heat transfer between the air and the refrigerant, thereby reducing the heat exchange efficiency of the evaporator 1.

Therefore, in order to prevent the deterioration of the performance of the evaporator 1 generated by the frost layer as described above, the defroster 1 is periodically provided with a defrosting operation.

2A and 2B are front and side views, respectively, of a defrosting apparatus of a refrigerator according to the prior art.

2A and 2B, the conventional refrigerator defrosting apparatus includes a first defrost heater and a second defrost heater (5) 7 mounted on the front and rear surfaces of the evaporator 1 and a lower side of the evaporator 1. The defrosting operation is performed periodically to remove the frost layer formed on the evaporator 1 through the first, second and third defrost heaters 5, 7, and 9, which are configured as a third defrost heater 9 mounted on the second defrost heater 9. It is supposed to be.

However, in the conventional defrosting apparatus of the refrigerator, since the first defrost heater 5 and the second defrost heater 7 are mounted on the front and rear of the evaporator 1, the frost layer of the evaporator 1 In the melting process, a large amount of moisture and residual ice are attached to the first defrost heater 5 and the second defrost heater 7, resulting in a long defrost time and an increase in power consumption.

That is, when moisture is attached to the first defrost heater 5 and the second defrost heater 7, the remaining ice of the evaporator 1 must be removed while vaporizing the moisture, and a large amount of heat and time are required to vaporize the moisture. Because of this consumption, the defrosting time is of course long, and if the defrosting time is long, there is a problem in that power consumption for defrosting is increased.

In addition, the defrosting apparatus of the refrigerator according to the prior art is because the first, second, third defrost heaters 5, 7, 9 are mounted on the front, rear, and bottom of the evaporator 1, respectively, to occupy considerable space. The number of tubes arranged in the evaporator 1 is limited by the heaters 5, 7, and 9, which has a problem of limiting the cooling performance of the refrigerator.

On the other hand, Figure 3 shows another defrosting apparatus, a defrost heater 14, which is a glass tube heater or a sheath heater, is installed at the bottom of the evaporator 10. The defrost heater 14 In case of heating, a large problem that defrosting efficiency due to limitation of defrosting part of the evaporator 10 is greatly reduced, such that the heater heat is not evenly applied to the entire evaporator 10, but only the lower part of the evaporator 10. Along with this, the heater heat takes a certain time until the entire evaporator 10 is acted on, such that the power consumption of the refrigerator is greatly increased.

In addition, in order to install the defrost heater 14 at the bottom of the evaporator 10, the lower end of the evaporator 10 should be formed as long as the installation space of the defrost heater 14, thereby limiting the space utilization of the refrigerator. There was also a huge problem.

Furthermore, in the case of the sheath heater of the defrost heater 14, because the power density (Watt Density) is high, the resulting surface temperature is raised to about 600 ℃ or more, by the temperature of the sheath heater of the evaporator 10 There was also a big problem such as the risk that the refrigerant (environmentally friendly alternative refrigerant R-600a: ignition temperature 494 ° C.) in the tube 11 exploded.

As such, in order to remove defrost (or frost) of the refrigerator evaporator, a defrost heater is generally used so that defrosting operation may be performed periodically. The defrost heater is an R-134a refrigerant, and L-code heaters, sheath heaters, and glass tube heaters are used.

The characteristics of the heaters applied to the defrosting apparatus are as follows.

Sheath heater is made by coiling the hot wire inside the pipe and filling high-purity magnesium oxide with excellent insulation and thermal conductivity at high pressure.It is durable against external mechanical shock or vibration, so it has a long life and is insulated even at high temperature. It is known to be very safe because there is no degradation. However, the sheath heater applied to the refrigerator evaporator is characterized by a very high surface temperature because the heat generation area is limited due to space limitations because the power density of the heater is high.

The L-code heater is mounted inside the aluminum pipe and is fixed in contact between the pin and the fixing bracket of the evaporator. At this time, since the heater must be fixed to the evaporator by hand, the work process is complicated and the cost increases. It conducts heat transfer mainly in the form of conduction and operates in low temperature areas.

The glass-tube heater seals the heating element inside the glass tube and performs defrosting using heat generated therein. It mainly transmits heat in a radiant manner and operates at high temperatures. Therefore, a protective device should be added so that defrost water does not directly fall on the heater.

The double tube heater has a feature of lowering the surface temperature by additionally covering a metal or glass tube in order to correspond to the combustible refrigerant.

However, when the refrigerant is a conventional HFC series such as R-134a, there is no problem in use regardless of the type of the heater. However, since the environmentally friendly refrigerant such as R-600a has a risk of explosion, the surface temperature of the heater is problematic.

In order to solve this problem, it is necessary to maintain the surface temperature of the heater sufficiently lower than the ignition point of the refrigerant. The heaters that can cope with this are the existing L-code heater and the newly attempted double tube heater. Among them, since the L-code heater conducts heat transfer in a conductive manner, it has a low surface temperature, but the price is increased due to the increase in manufacturing and assembly processes. In addition, the double tube heater has a form in which one layer of glass or other metal tube is overlaid on the existing glass tube heater, thereby reducing the amount of heat generated per unit area on the surface of the heater. However, both types of heaters have high cost and are inconvenient in manufacturing and bonding.

The present invention has been made to solve the above problems, an object of the present invention is to provide a defrosting apparatus of a refrigerator that can be defrosted uniformly by coupling a flexible surface heater to the outer peripheral surface of the evaporator.

An object of the present invention is to attach a planar heater consisting of an insulating film and heater wires arranged in a straight line at appropriate intervals inside the film on both sides of the evaporator, by cutting the central portion of the planar heater coupled in the downward direction of the evaporator to exchange cold air and It is an object of the present invention to provide a defrosting device of a refrigerator that can be used as a defrost receiving heater.

Another object of the present invention is to provide a defrosting apparatus of a refrigerator which can be applied to an evaporator in consideration of the intervals, arrangement directions, current strengths, distributions, etc. of heater wires formed in an insulating film of a planar heater.

Defrosting device according to the present invention for achieving the above object,

An evaporator having fins and tubes;

In order to remove the surface frost layer of the evaporator, the first and second surface heaters with the left and right surfaces opposed to the front and rear surfaces of the evaporator and the center surface branched from the first and second surface heaters to the defrost receiver under the evaporator. The third surface heater faced, the cold air inlet opening to communicate with the lower portion of the evaporator is integrally processed, characterized in that it comprises a surface heater that generates heat in accordance with the power supply.

Preferably, the first, second, and third surface heaters share power and are separated into independent heaters, and the front, rear, and defrost water receivers of the evaporator are characterized in that they face each.

Preferably, the first and second surface heaters are attached to the front and rear of the evaporator by an adhesive member applied to the attachment surface to the evaporator.

Preferably, the first and second surface heaters are fixed by heater fixing means formed on the first and second surface heater sides and the evaporator side to correspond to each other so as to be fixed to the front and rear surfaces of the evaporator.

Hereinafter, with reference to the accompanying drawings as follows.

4 is a view showing a defrosting apparatus of a refrigerator according to an embodiment of the present invention.

Referring to FIG. 4, a fin-tube integrated evaporator 110, a flexible planar heater 210 for removing frost by being in surface contact with the evaporator 110, the evaporator 110 and a planar heater 210. And means for engaging and fixing.

The evaporator 110 is formed through a louvering process after integrally extruding the tube 111 and the tube 111 to connect the inlet to the outlet of the expansion valve and the outlet to the inlet of the compressor to guide the refrigerant to the compressor. The pin 112 and the tube bracket 113 is arranged on the left and right of the tube 111 to support the tube side portion.

The planar heater 210 is a heating element arranged in a "r" shape and the heater wire 211 to generate heat according to the power supply; Insulation and protection by pressing the heater wire therein and consists of an insulating film 212 attached to the front and rear sides of the evaporator (110).

Then, the adhesive 250 is applied as shown in Figure 6 as a means for fixing the evaporator 110 and the planar heater 210.

Referring to the accompanying drawings of the defrosting apparatus of the refrigerator according to the present invention as described above are as follows.

As shown in FIG. 4, the fin-tube integrated evaporator 110 is composed of a tube 111, a fin 112, and a tube bracket 113. The tube 110 connects the inlet to the outlet of the expansion valve, connects the outlet to the inlet of the compressor, and is stacked and communicated in a vertical direction in the form of an "S" to guide the refrigerant to the compressor, and arranged in two rows side by side in the horizontal direction. Structure. Fin 112 is integrally extruded between the "S" shaped tube 111 arranged horizontally and then formed through a louvering process, thereby improving heat exchange performance.

Here, the fin 112 is bent about 70 to 75 degrees along the longitudinal direction of the tube 111 through louvering so that air can pass from the lower end of the tube to the upper direction in the center of the fin formation portion of the tube 111. Many are formed continuously.

In addition, the tube bracket 113 has a trapezoidal structure such that a plurality of vertically arranged and horizontally arranged tubes 111 are inserted at the intersections of straight and curved lines at the left and right sides of the “S” shaped tube 111. Will be supported.

On the other hand, the surface heater 210 for the defrost of the evaporator 110 wraps the entire surface of the evaporator 110 and the surface contact, it is possible to perform the defrosting uniformly. To this end, the planar heater 210 is fixed in a rectangular insulation film 212 and the heater wire 211 having a loop of the letter "L" in the insulation film is arranged at a predetermined interval.

The insulation film 212 uses a film (or pad) made of a strong and flexible material at high temperature, and is made transparent / semi-transparent. In addition, the heater wire 211 is an aluminum coil as an example, and is arranged to be orthogonal to the tube direction in the shape of a "d". In an embodiment, the heater wires may be arranged in the same direction as the tube direction, or may have different shapes or different intervals (distribution). In an embodiment, each loop may be connected to a different loop or an arbitrary loop instead of a single loop.

Specifically, the surface heater 210 includes a first surface heater 220 attached to the front surface of the evaporator 110, a second surface heater 230 opposed to the rear surface of the evaporator 110, and an evaporator 110. The defrost area is divided into a third surface heater 240 for defrost water receiving branches branched in a "c" shape from the lower ends of the first and second surface heaters 220 and 230 at the bottom position of the first and second surface heaters. The heater 240 is integrally formed and connected to the heater wire 211 in a single loop.

Here, the third surface heater 240 is adhered to the defrosting water receiver (not shown) in the lower portion of the surface heater 210 to defrost the defrost water falling from the evaporator 110 and the cold air due to defrosting is upward. And the space which processed the 3rd surface heater 240 by the surface heater 210 functions as the cold air inlet 241, and convection generate | occur | produces in an upward direction.

The insulating film 212 of the planar heater 210 has a rectangular structure and has a first heater area H1 on the front surface of the evaporator 110, a rear surface of the evaporator 110 on the second surface heater area H2, It is divided into a third surface heater region H3 for defrost water receiving located under the evaporator processed at the center thereof. Here, the connection between the first surface heater 220 and the second surface heater 230 is connected to the connection portion 213, the heater line between the two surface heater area is connected by the connection portion 213.

The third surface heater region H3 for receiving the defrost water is processed into a concave-convex shape in a central region between the first surface heater region H1 and the second surface heater region H2, and the concave shape is lower than the evaporator. It is a cold air inlet 241 open to the third surface heater 240 for the defrost water receiver is attached to the defrost water receiver for receiving the defrost water falling in the downward direction from the evaporator. As an embodiment, the planar heater center may be provided with only the cold air inlet by the connection part 213 and the third planar heater may be removed, and such a structure may be coupled to the evaporator in the form of a shoulder strap. In addition, it is preferable to couple a separate heater to the defrosting water receiver when removing the third surface heater.

Coupling of the surface heater to the evaporator, as shown in FIG. 5, attaches the first surface heater region H1 of the surface heater 210 to the front of the evaporator, and then wraps the lower surface of the evaporator 110 so that the second surface heater region H2 is evaporator. Attach to the back. At this time, the adhesive 250 is applied to the attachment surface (heating surface) of the planar heater 210 to facilitate attachment with the evaporator 110 as shown in FIG. 6. That is, the heating surface of the surface heater 210 is attached in close contact with the side of the tube 111 and the bracket 113 of the evaporator 110. In an embodiment, the surface heater may be fixed to the evaporator side as a fixing means other than the adhesive.

Here, the heater wire 211 is connected as a single loop and has a soldering portion 211a at the inlet side of the insulating film, and the heater wire of the insulating film has a structure in which a plurality of heater wires are compressed as shown in FIG. The defrosting effect can be enhanced by adjusting the interval d between the teeth.

As such, the planar heater 210 is folded in the evaporator 110 and wrapped around the front and rear of the evaporator as shown in FIG. 7, and cold air is provided at a lower portion so that the air coming in through the return duct from the refrigerating compartment and the freezing compartment can pass. Inlet 241 is a structure that is open.

In addition, the same space as the cold air inlet 241 drilled for air circulation in the lower portion of the surface heater 210 is attached to the defrost water receiver as the third surface heater 240 for defrost water receiving, so that defrost water and water falling from the evaporator If ice cubes that do not fall on the defrost tray are heated, the heated air rises and convection. That is, by opening the cold air inlet 241 for air circulation in the lower part of the evaporator under the surface heater 210 and installing the third surface heater 240 for receiving defrost water, defrosting the ice mass that did not become water. Preventing the blockage of the flow path of the defrosting water while preventing the blockage, the heated air rises by convection to help the defrosting action as it is located at the bottom of the evaporator.

The defroster is designed to operate at a predetermined time by the refrigerator control system. In the case of medium / large size, the surface temperature of the surface heater rises to a certain temperature (for example, about 200 ° C.) during operation, so that the frost accumulated on the surface of the evaporator is increased. The layer can be melted.

Operation by the defrosting apparatus of the refrigerator of the present invention is as follows.

The surface heater 210 which is a defrost heater on the front / rear of the evaporator 110 is circulated in the freezer compartment and the refrigerating compartment and is re-introduced through the bottom of the evaporator and the inside of the tube 111 of the evaporator 110. The frost is formed on the tube 111 and the fin 112 of the evaporator 110 by the temperature difference with the flowing refrigerant. At this time, the operation of the refrigeration cycle was stopped to defrost the frost formed on the evaporator 110, and then supplying power to the surface heater 210 fixed in close contact with the front / rear of the evaporator 110, the surface heater (210) Exothermic and endothermic action at the inner / outer surface is transferred directly to the entire evaporator 110 through conduction and convection to remove frost on the tubes 111 and fins 112 of the evaporator 110. Defrost work is done.

As a result, the temperature of the freezer compartment is prevented from being increased by the heat transferred up to the evaporator 110 while absorbing the heat transferred up to the evaporator 110.

Accordingly, the defrosting action of removing frost formed on each part of the evaporator 110 by the heater heat generated from the surface heater 210 is uniformly performed. In particular, in the defrosting operation as described above, the heat of the surface heater 210 tightly fixed to the front and rear surfaces of the evaporator 110 has a risk of explosion in the refrigerant flowing in the tube 111 of the evaporator 110. Defrost work is done safely without giving.

Since the planar heater has a large heating surface, the surface temperature is low (explosion proof) for the same heater output, and the entire heater is enveloped so that defrosting can be performed more uniformly than conventional defrosting methods.

In addition, the loops of the heater wires inserted into the insulating film or the insulating pad of the planar heater are arranged to be orthogonal to the tubes of the evaporator in a vertical direction with respect to a single loop and a plurality of loops, or the planar heater 310 as shown in FIG. The heater wires 311 may be arranged parallel to the horizontal direction with respect to the evaporator tube direction. In addition, the distribution (or spacing) of the heater wire may be taken differently in consideration of the tube of the evaporator and the defrosting effect of the evaporator.

The planar heaters 210 and 310 as described above are integrated as an exemplary embodiment, but each of the planar heaters is divided into two and three sections, and each loop is independently installed by one or each of the planar heaters, thereby defrosting through heat generation. You can also control.

9 is another embodiment of the present invention, the planar heater 410 is separated into independent heaters as the first, second, and third planar heaters 420, 430 and 440, respectively, and the insulating film 412 of each planar heater 420, 430 and 440 The heater wires 411 coated in the N-poles are formed of individual loops in each of the heaters on the surface, and share the power supplied to each heater wire. That is, the first and second heaters 420 and 430 are attached to the front and rear surfaces of the evaporator, respectively, and the third heater 440 is attached to the defrosting water receiver, and the heater wire 411 generates heat in each heater. By drawing the shared power (+,-) to be applied, it is possible to control the defrost.

The fixed structure of the planar heater configured as described above is not only a top-type refrigerator applied as an embodiment of the present invention but also a bottom-type refrigerator in which a refrigerating compartment is located at the top and a freezer compartment is at the bottom. The refrigerator and the freezer compartment and the refrigerating compartment of the can also be applied to the side by side type (Side By Side-Type) refrigerators located on the left and right sides of the main body.

As described above, according to the refrigerator defrosting apparatus according to the present invention, by defrosting by using a single-sided surface heater in contact with both sides of the evaporator, it is possible to improve the heat transfer performance for the evaporator, reduce the power consumption, the internal temperature of the refrigerator There is an effect that can prevent the rise.

In addition, by defrosting the evaporator with a surface heater of a single heating element, there is an effect of reducing the manufacturing cost.

Claims (4)

An evaporator having fins and tubes; In order to remove the surface frost layer of the evaporator, the first and second surface heaters with the left and right surfaces opposed to the front and rear surfaces of the evaporator and the center surface branched from the first and second surface heaters to the defrost receiver under the evaporator. Defrosting apparatus comprising a planar heater is formed integrally with the third surface heater to be faced, the cold air inlet open to communicate with the lower portion of the evaporator. The method of claim 1, The first, second, and third surface heaters share a power source, and are separated into independent heaters, and the defrosting apparatus is characterized in that the front and rear surfaces of the evaporator are attached to the defrost water receivers, respectively. The method according to claim 1 or 2, Defrosting apparatus characterized in that the first and second surface heater is attached to the front and rear of the evaporator by an adhesive member applied to the attachment surface with the evaporator. The method according to claim 1 or 2, Defrosting apparatus characterized in that the first and the second surface heater is fixed by the heater fixing means formed to correspond to each other on the first and second surface heater side and the evaporator side, so as to be fixed to the front and rear of the evaporator.

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