AU2020431079B2 - Refrigerator - Google Patents

Abstract

A refrigerator (100) according to the present disclosure comprises: double swing-type doors (2, 3); a plate member (31) that, via the outer surface thereof, closes a gap formed between the double swing-type doors (2, 3) when the double swing-type doors (2, 3) have been closed; and a heater (32) that heated the plate member (31), the heater (32) being provided on the inner surface side of the plate member (31). The heater (32) is set apart from an end part of the plate member (31). The refrigerator (100) further comprises a graphite sheet (35) that conductively transfers the heat of the heater (32) to a surface of the plate member (31) located between the end part of the plate material (31) and the heater (32). The graphite sheet (35) is a member in which the thermal conductivity in the direction along the inner surface is higher than the thermal conductivity in the direction from the inner surface to the outer surface.

Description

REFRIGERATOR

Technical Field

[0001]

The present disclosure relates to a refrigerator provided with double doors. Background Art

[0002]

Double-door refrigerators having an opening, through which an object to be

stored is put in and taken out, and having two doors that close the opening are known.

With the opening being closed, there is a gap between the two doors so that the two

doors are not in contact with one another when a door is opened and closed. One side

of the double doors has a partition, which is capable of rotating, for preventing the cold

air inside the refrigerator from flowing out through the gap. When the one side of the

double doors closes part of the opening, the partition rotates, and a plate provided as a

portion of the partition closes the gap.

[0003]

The plate is cooled by the cold air inside the refrigerator, and condensation forms

on the outside face of the plate. For preventing such condensation from forming, a

heat insulator is provided so as to cover the inside face of the plate facing the inside of

the refrigerator, and the plate is thereby suppressed from being cooled by the cold air

inside the refrigerator. In addition, a heater is provided at the plate so as to transfer

heat, and the heater heats the plate to suppress condensation from forming (for

example, refer to Patent Literature 1 below).

Citation List

Patent Literature

[0004]

Patent Literature 1: Japanese Unexamined Patent Application Publication No.

2013-221715

Summary of Invention

Technical Problem

[0005] However, regarding such a refrigerator of Patent Literature 1 described above, an

end portion of the plate is not covered with a heat insulator, thereby being cooled by the

cold air inside the refrigerator. Thus, the temperature of the end portion of the plate is

more likely to decrease than the temperature of a central portion of the plate. In

addition, the heater is provided in an inner region (central region) of the plate while

being spaced apart from the end portion of the plate, and the temperature of the end

portion is thereby likely to decrease. Thus, the electric power supplied to the heater is

required to be increased to heat sufficiently the end portion of the plate so that

condensation does not form.

[0006]

The present disclosure has been made to solve such an above-described

problem, and the present disclosure advantageously provides a refrigerator capable of

reducing the power consumption of a heater provided for preventing condensation from

forming on a plate.

Solution to Problem

[0007]

A refrigerator according to an embodiment of the present disclosure includes

double doors, a plate having an outside face that closes a gap left between the double

doors with the double doors being closed, and a heater that is provided beside an inside

face of the plate and heats the plate. The heater is spaced apart from an end portion

of the plate. In addition, the refrigerator further includes a graphite sheet that transfers

heat of the heater to a region of the plate between an end portion of the plate and the

heater. The graphite sheet has a thermal conductivity, in a direction parallel to the

inside face, higher than a thermal conductivity thereof in a direction from the inside face

toward the outside face.

Advantageous Effects of Invention

[0008]

The refrigerator according to an embodiment of the present disclosure includes

the graphite sheet having a thermal conductivity, in the direction parallel to the inside face of the plate, higher than the thermal conductivity thereof in the direction toward the outside face of the plate, and the graphite sheet conducts heat to a region of the plate between the end portion of the plate and the heater. Thus, the heat generated at the heater is hardly transferred inside or outside the refrigerator but is likely to be transferred, along the inside face of the plate, to a portion around the end portion at which the heater is not provided. Accordingly, it is possible to transfer heat efficiently to the end portion of the plate and thus to reduce the power consumption of the heater.

Brief Description of Drawings

[0009]

[Fig. 1] Fig. 1 is a perspective view of a refrigerator according to Embodiment 1 of

the present disclosure.

[Fig. 2] Fig. 2 is a sectional view of the refrigerator according to Embodiment 1 of

the present disclosure.

[Fig. 3] Fig. 3 is a schematic view of a refrigerant circuit of the refrigerator

according to Embodiment 1 of the present disclosure.

[Fig. 4] Fig. 4 is a perspective view of double doors of the refrigerator according

to Embodiment 1 of the present disclosure.

[Fig. 5] Fig. 5 is a sectional view (the Y-Z plane) of a partition of the refrigerator

according to Embodiment 1 of the present disclosure.

[Fig. 6] Fig. 6 is a sectional view (the X-Y plane) of the partition of the refrigerator

according to Embodiment 1 of the present disclosure.

[Fig. 7] Fig. 7 is a perspective view of a plate of the refrigerator according to

Embodiment 1 of the present disclosure.

[Fig. 8] Fig. 8 is an exploded perspective view of the partition according to

Embodiment 1 of the present disclosure.

[Fig. 9] Fig. 9 is an enlarged view of the section (the Y-Z plane) of the partition of

the refrigerator according to Embodiment 1 of the present disclosure.

[Fig. 10] Fig. 10 is a sectional view (the Y-Z plane) of a partition of the refrigerator

according to Embodiment 1 of the present disclosure.

[Fig. 11] Fig. 11 is a sectional view (the Y-Z plane) of a partition of the refrigerator

according to Embodiment 1 of the present disclosure.

[Fig. 12] Fig. 12 is a graph showing the temperature of a partition of the

refrigerator according to Embodiment 1 of the present disclosure.

[Fig. 13] Fig. 13 is a graph showing annual power consumption of a heater of the

refrigerator according to Embodiment 1 of the present disclosure.

[Fig. 14] Fig. 14 includes, regarding a refrigerator according to Embodiment 2 of

the present disclosure, a perspective view of a plate and a sectional view (the Y-Z

plane) of a partition.

Description of Embodiments

[0010]

Hereinafter, embodiments of the present disclosure will be described with

reference to the drawings. The identical or equivalent portions are denoted by the

same reference in the drawings.

[0011]

Embodiment 1

First, the overall configuration of a refrigerator 100 according to Embodiment 1 of

the present disclosure will be described with reference to Figs. 1 to 3.

Fig. 1 is a perspective view of the refrigerator 100, and the near side of Fig. 1 is

the front of the refrigerator 100. Fig. 2 is a sectional view of the refrigerator 100 when

the refrigerator 100 is cut along section II-II in Fig. 1. Fig. 3 is a schematic view of a

cooling circuit of the refrigerator 100 illustrated in Fig. 2.

[0012]

As Fig. 1 illustrates, the refrigerator 100 has a housing 1 having a hexahedral

shape, and there are provided, at the front of the housing 1, between a top plate 1a and

a bottom plate 1b, a door 2 and a door 3 constituting double doors and an ice-making

compartment drawer 4, a versatile compartment drawer 5, a freezer compartment

drawer 6, and a vegetable compartment drawer 7. Here, when the refrigerator 100 is

installed, the bottom plate 1b is in contact with a floor of a building, and the top plate 1a is positioned opposite to the bottom plate 1b and disposed on side of a ceiling of the building.

The housing 1 includes five spaces for storing objects to be stored. As Fig. 2

illustrates, four spaces of the five spaces serve as a refrigerator compartment 11, a versatile compartment 13, a freezer compartment 14, and a vegetable compartment 15

that are arranged in this order from top. The other space serves as an ice-making

compartment disposed at the back of the versatile compartment 13 in Fig. 2. The

spaces are provided for cooling stored objects at different temperatures and are

separated from one another by partition plates 1c, 1d, and le that are made of a resin

material including a heat insulator material. The housing 1 further has, at the front of

the refrigerator 100, an opening through which each of the spaces and the outside

communicate with one another and through which objects to be stored can be put in

and take out.

As Fig. 1 illustrates, the housing 1 has the doors 2 and 3 on both sides of the

opening of the refrigerator compartment 11 so as to rotate, and each of the doors 2 and

3 rotates to close and open part of the opening. Between the door 2 and the door 3, there is a gap with the door 2 and the door 3 being closed. The gap extends in a

direction from the top plate 1a toward the bottom plate 1b of the housing 1.

In addition, the ice-making compartment drawer 4, the versatile compartment

drawer 5, the freezer compartment drawer 6, and the vegetable compartment drawer 7

are respectively provided at the openings of the ice-making compartment, the versatile

compartment 13, the freezer compartment 14, and the vegetable compartment 15 so

that the drawer can slide in a direction away from the housing 1.

[0013]

A cooling device 20 is provided in a back region of the housing 1. As Fig. 2 and

Fig. 3 illustrate, the cooling device 20 is constituted by a compressor 21, a condenser

22, an expansion unit 23, an evaporator 24, a fan 25, and a defroster 26.

As Fig. 3 illustrates, the compressor 21 connected to the condenser 22

adiabatically compresses refrigerant and delivers the high-temperature, high-pressure

gaseous refrigerant to the condenser 22. The condenser 22 connected to the expansion unit 23 exchanges heat between the air outside the housing 1 and the refrigerant to liquefy the refrigerant and delivers the liquid refrigerant to the expansion unit 23. The expansion unit 23 constituted by a capillary tube connected to the evaporator 24 expands the refrigerant and delivers the refrigerant in a two-phase gas liquid state to the evaporator 24. The evaporator 24 exchanges heat between return air 27 inside the housing 1 and the refrigerant to gasify the refrigerant while cooling the air inside the housing 1. In addition, the evaporator 24 is connected to the compressor

21 and delivers the gasified refrigerant to the compressor 21. The compressor 21, the

condenser 22, the expansion unit 23, and the evaporator 24 constitute a refrigerant

circuit for cooling the air inside the housing 1.

In addition, the cooling device 20 delivers the cold air that has been cooled by the

evaporator 24 to each space by the fan 25 and maintains each space at low

temperature. The air that has been delivered by the fan 25 returns, as the return air

27, from each space to the cooling device 20 and is cooled again to be delivered to

each space.

The cooling device 20 includes the defroster 26 at a position toward which the

return air 27 blows, and the defroster 26 is driven at regular intervals to suppress frost

from forming on the evaporator 24.

[0014]

In addition, as Fig. 2 illustrates, heat transfer pipes 16a, 16b, and 16c are

embedded respectively inside the partition plates 1c, 1d, and le that divide the inside

space of the housing 1. Each of the partition plates 1c, 1d, and 1e separates the

spaces having different temperatures, and condensation may thereby form on the

partition plates 1c, 1d, and 1e. Thus, high-temperature fluid is caused to flow through

each of the heat transfer pipes 16a, 16b, and 16c to heat the partition plates 1c, 1d, and

1e.

[0015] Up to this point, the overall configuration of the refrigerator 100 is described.

The space serving as the refrigerator compartment 11 is equivalent to a first space, and

the space serving as the ice-making compartment or the versatile compartment 13 is equivalent to a second space. In the following description, a region around the top plate 1a is the upper region of the refrigerator 100, and a region around the bottom plate

1b is the lower region of the refrigerator 100. In addition, the direction perpendicular to

the vertical direction and to the direction in which the front side and the back side of the

refrigerator 100 are connected to one another is the lateral direction of the refrigerator

100. Note that the Z direction in the drawings is equivalent to the vertical direction, the

Y direction is equivalent to the direction in which the front side and the back side of the

refrigerator 100 are connected to one another, and the X direction is equivalent to the

direction in which the lateral faces of the refrigerator 100 are connected to one another.

[0016] Next, a partition 30 included in the refrigerator 100 will be described with

reference to Figs. 4 to 9.

Fig. 4 is an enlarged view of a portion equivalent to the refrigerator compartment

11 of the refrigerator 100 when viewed from a position in front of the refrigerator 100.

Fig. 5 illustrates the refrigerator 100 cut along section V-V in Fig. 4. Fig. 6 illustrates

the refrigerator 100 cut along section VI-VI in Fig. 4 while enlarging the vicinity of the

partition 30. Fig. 7 is a perspective view of a plate 31 that is a portion of the partition

30. Fig. 8 is an exploded perspective view of a heat insulator 33, a heater 32, a

graphite sheet 35, and the plate 31 that constitute the partition 30. Fig. 9 is an

enlarged view of Fig. 5.

The partition 30 has the plate 31, the graphite sheet 35, the heater 32, the heat

insulator 33, and a case 34 (Fig. 5). Note that, in Fig. 5, the reference 39a denotes the

inside of the housing 1, the reference 39b denotes the outside of the housing 1, and the

plate 31, the graphite sheet 35, the heater 32, the heat insulator 33, and the case 34 are

arranged, in this order, from the outer face of the housing 1. The partition 30 is

provided on a side of the door 2 facing the door 3 so as to rotate. With the door 2

being closed, the partition 30 is disposed so that the outside face, of the plate 31,

positioned at the outer face of the housing 1 is substantially parallel to a face of the door

2 at the front. When the door 2 is opened, the partition 30 is accordingly folded to be

at a position beside the lateral face of the door 2. In addition, regarding the partition

30, as Fig. 4 illustrates, the outside face of the plate 31 closes the gap that is left

between the door 2 and the door 3 when the door 2 and the door 3 close the opening of the refrigerator compartment 11.

[0017]

The plate 31 is a quadrangular sheet of metal made of a metallic material such as

iron, aluminum, copper, or stainless steel. More specifically, the plate 31 is a

rectangular sheet of metal whose longitudinal direction is parallel to the direction in

which the gap between the door 2 and the door 3 extends, that is, the vertical direction.

In addition, as Fig. 5 illustrates, the plate 31 has flanges 36a and 36b extending

respectively from an upper end portion and a lower end portion of the plate 31 toward

the case 34 (toward the inside of the housing 1). As Fig. 7 illustrates, each of the

flange 36a and the flange 36b has a quadrangular shape (section (a) of Fig. 7), a fan

shape (section (b) of Fig. 7), or a triangular shape (section (c) of Fig. 7). When each of

the flanges 36a and 36b has a quadrangular shape, a portion near each end portion of

the plate 31 may be bent. When having a fan shape or a triangular shape, the flanges

36a and 36b may further be cut to have the shape.

The plate 31 has a dimension, in the longitudinal direction thereof, shorter than

the dimension of the gap, which is left between the door 2 and the door 3 when the

opening of the refrigerator compartment 11 is closed by the door 2 and the door 3.

There are gaps between an upper wall (the top plate 1a) of the refrigerator compartment

11 and the plate 31 and between a lower wall (the partition plate 1c) of the refrigerator

compartment 11 and the plate 31 (Fig. 5). For preventing cold air from flowing out

through the gaps, a gasket 37a and a gasket 37b are provided respectively on the front

face of the top plate 1a and on the front face of the partition plate 1c, and the plate 31

comes into contact with the gaskets 37a and 37b when closing the gap between the

door 2 and the door 3. In addition, as Fig. 6 illustrates, a gasket 37c is provided in the

vicinity of an end portion of the door 2 that faces the door 3 when the doors 2 and 3

close the opening of the housing 1, and, in a similar way, a gasket 37c is also provided

in the vicinity of an end portion of the door 3. When closing the gap between the door

2 and the door 3, the plate 31 comes into contact with the gaskets 37c. The gaskets

37a and 37b and the gaskets 37c are made of a rubber material having high wear

resistance.

In addition, as Fig. 6 illustrates, throats 38a and 38b protruding respectively from

the faces of the doors 2 and 3 facing the inside of the housing are provided beside the

lateral faces of the partition 30. The throats 38a and 38b suppress the cold air inside

the housing 1 from blowing against the lateral faces of the partition 30 and thus

suppress the temperature of the partition 30 from decreasing.

[0018] The heater 32 is a cord heater provided beside the inside face of the plate 31,

that is, beside the back face of the plate 31 (facing the inside of the housing 1) and

heats the plate 31 to suppress condensation from forming. In addition, as Fig. 8

illustrates, the heater 32 is a single cord heater provided in a region of the plate 31 on

the inner side (on the central side) relative to the end portions of the plate 31. When

the plate 31 is viewed from a position inside the housing 1 toward the inside face of the

plate 31, the heater 32 does not extend to the vicinity of each end portion of the plate

and is disposed in an inner region of the plate 31 while being spaced apart from the end

portions of the plate 31.

Regarding the heater 32, the outer periphery of a heating wire is covered with an

insulating coating, and a short circuit due to contact with, for example, the plate 31 is

suppressed from occurring.

[0019]

The heat insulator 33 is made of a foamed plastic-based material such as styrene

foam or urethane foam having a thermal conductivity of the order of 10-2 W/m-K and

suppresses heat intrusion from the heater 32 into the housing 1 and heat leakage from

the housing 1 to the outside. As Fig. 5 and Fig. 6 illustrate, the heat insulator 33 is

provided so as to cover the heater 32 and the inside face of the plate 31.

[0020]

The case 34 having a box shape is provided at a position where the case 34

faces the inside face of the plate 31 with the heater 32 interposed therebetween and is

made of a resin material such as acrylic or polycarbonate. As Fig. 5 and Fig. 6 illustrate, the case 34 has a hexahedral shape, and one side of the case 34 is open.

The heat insulator 33, the heater 32, and the graphite sheet 35 are accommodated in

and surrounded by the case 34. In addition, the upper and lower walls of the case are respectively in contact with the flange 36a and the flange 36b of the plate 31, and such

walls and the flange 36a and the flange 36b are fixed to one another by fastening tools

such as screws. The plate 31 is fixed to the case 34 with the flanges 36a and 36b so as to cover the opening of the case 34.

[0021]

The graphite sheet 35 has a sheet shape and contains graphite. The sheet

having a thickness of 40 pm to 100 pm is used. The graphite sheet 35 is provided on the heater 32 so as to transfer heat, namely conduct heat. More specifically, the

graphite sheet 35 is provided so as to transfer heat to at least a region of a face of the

plate 31 around an end portion of the plate 31 at which the heater 32 is not provided.

In other words, when viewed from a position inside the housing 1 toward the inside face

of the plate 31, the graphite sheet 35 is provided so as to transfer the heat of the heater

32 to a region of the face of the plate 31 between the end portion of the plate 31 and the

heater 32, that is, the graphite sheet 35 is capable of heat conduction. In the example

illustrated in Fig. 5, the graphite sheet 35 is provided not only in a region of the inside

face around the end portion of the plate 31. The graphite sheet 35 is provided on the

entire inside face of the plate 31 so as to transfer heat. The graphite sheet 35 is

further provided on the entire portion of the heater 32 facing the plate 31 so as to

transfer heat. As described above, the graphite sheet 35 is provided between the

inside face of the plate 31 and the heater 32.

The graphite contained in the graphite sheet 35 has plural layers of hexagonal

plate-shaped crystals in which carbon atoms are covalently bonded to one another, and

the layers of plate-shaped crystals of the graphite sheet are oriented along the sheet in

plane of the graphite sheet 35. Thus, the graphite sheet 35 has a thermal conductivity, in the in-plane direction, larger than the thermal conductivity thereof in the sheet

thickness direction and thus has anisotropy in thermal conductivity. The graphite sheet

35 is disposed along the inside face of the plate 31, and the layers of plate-shaped crystals of the graphite are thereby oriented along the inside face of the plate 31.

Thus, the graphite sheet 35 has a thermal conductivity, in the direction parallel to the

inside face of the plate 31, higher than the thermal conductivity thereof in the direction

from the inside face toward the outside face of the plate 31. Specifically, the thermal

conductivity in the direction parallel to the inside face is 1500 W/m-K and is nearly 20

times higher than the thermal conductivity of iron, which is an example of a material

used for the plate 31, that is, about 80 W/m-K. In addition, the thermal conductivity in

the direction from the inside face toward the outside face is about 10 W/m-K and is

lower than the thermal conductivity of iron. Thus, the heat generated by the heater 32

is likely to be transferred along the inside face of the plate 31 and is thus likely to diffuse

to the end portion of the plate 31. In contrast, the heat is hardly transferred in the

direction from the inside face to the outside face of the plate 31, and heat leakage to the

outside of the refrigerator 100 is thereby reduced.

[0022]

As Fig. 9 illustrates, the graphite sheet 35 has adhesive tape pieces 35a and 35b

on both lateral faces and is stuck to the heater 32 with the adhesive tape piece 35a.

The graphite sheet 35 is further stuck to the plate 31 with the adhesive tape piece 35b.

Each of the adhesive tape pieces 35a and 35b is formed by tape such as aluminum

tape, vinyl tape, or polyimide tape that can reduce thermal contact resistance, and the

heat from the heater 32 is efficiently transferred to the graphite sheet 35 and to the plate

31.

[0023]

Here, modifications of the partition 30 of Embodiment 1 will be described with

reference to Fig. 10. Fig. 10 is a sectional view of a partition 30 and equivalent to the

sectional view of Fig. 5.

The example of section (a) of Fig. 10 is similar to the example of the partition 30

illustrated in Fig. 5, and the graphite sheet 35 is provided on the entire inside face of the

plate 31. Note that the reference "L" in section (a) of Fig. 10 denotes the length of the

plate 31 in the vertical direction (longitudinal direction). In this example, heat can efficiently be transferred to both the upper end portion and the lower end portion of the plate 31. In the example of section (b) of Fig. 10, a graphite sheet 35 is provided in a region of the plate 31, in the longitudinal direction of the plate 31, closer to the upper end portion than to the center of the plate 31. The graphite sheet 35 has a length of L/4 and is provided within an L/4 range from the upper end portion of the plate 31. As in Embodiment 1, when the heat transfer pipe 16a is provided near the lower end portion of the plate 31 (refer to Fig. 2 and Fig. 5), the temperature of the lower end portion of the plate 31 hardly decreases. In such an instance, this example is preferably adopted. In addition, because having the flange 36a, the upper end portion of the plate 31 is likely to be cooled; however, it is possible to suppress the temperature of the upper end portion from decreasing by the graphite sheet 35 being provided as described above on a portion around of the upper end portion, in the plate 31, having the flange 36a.

In the example of section (c) of Fig. 10, a graphite sheet 35 is provided in a

region of the plate 31, in the longitudinal direction of the plate 31, closer to the upper

end portion than to the center of the plate 31. The graphite sheet 35 has a length of

L/2 and is provided within an L/2 range from the upper end portion of the plate 31. In

this example, heat is also efficiently transferred to the upper end portion of the plate 31,

and the example is thus similar to the example of section (b) of Fig. 10.

In the example of section (d) of Fig. 10, a graphite sheet 35 is provided in a

region of the plate 31, in the longitudinal direction of the plate 31, closer to the lower

end portion than to the center of the plate 31. The graphite sheet 35 has a length of

L/4 and is provided within an L/4 range from the lower end portion of the plate 31. In

this example, heat can efficiently be transferred to the lower end portion of the plate 31.

Unlike Embodiment 1, this example is preferably adopted when a heat transfer pipe is

provided near the upper end portion of the plate 31. In addition, because having the

flange 36b, the lower end portion of the plate 31 is likely to be cooled; however, it is

possible to suppress the temperature of the lower end portion from decreasing by the graphite sheet 35 being provided on a portion around the lower end portion, in the plate

31, having the flange 36b. In the example of section (e) of Fig. 10, a graphite sheet 35 is provided in a

region of the plate 31, in the longitudinal direction of the plate 31, closer to the lower

end portion than to the center of the plate 31. The graphite sheet 35 has a length of

L/2 and is provided within an L/2 range from the lower end portion of the plate 31. In

this example, heat is also efficiently transferred to the lower end portion of the plate 31,

and the example is thus similar to the example of section (d) of Fig. 10.

In the example of section (f) of Fig. 10, graphite sheets 35 are provided in a

region of the plate 31, in the longitudinal direction of the plate 31, closer to the upper

end portion than to the center of the plate 31 and in a region of the plate 31, in the

longitudinal direction of the plate 31, closer to the lower end portion than to the center of

the plate 31. The graphite sheets 35 have a length of L/4. One of the two graphite

sheets 35 is provided within an L/4 range from the upper end portion of the plate 31,

and the other is provided within an L/4 range from the lower end portion of the plate 31.

In this example, as in the example of section (a) of Fig. 10, heat can efficiently be

transferred to both the upper end portion and the lower end portion of the plate 31.

[0024]

Next, there will be described, with reference to Figs. 11 to 13, the efficiency of

thermal diffusion to the upper end portion of the plate 31 and the power consumption of

the heater 32, when the heater 32 is energized, with the heat transfer pipe 16a, which is

provided near the lower end portion of the plate 31, transferring heat.

Fig. 11 includes sectional views of the configurations of partitions 30 and 30' of a

comparative example and Examples 1 to 3, the examples being given for evaluating the

efficiency of thermal diffusion of the plate 31.

Four partitions 30 illustrated in Fig. 11 are prepared for evaluating the efficiency

of thermal diffusion of the plate 31 on which a graphite sheet 35 is provided. A partition

30' illustrated in section (a) of Fig. 11 does not have a graphite sheet 35. There are

arranged a temperature sensor 40a near the upper end portion of the plate 31, a

temperature sensor 40c near the center of the plate 31, a temperature sensor 40e near the lower end portion of the plate 31, a temperature sensor 40b between the temperature sensor 40a and the temperature sensor 40c, and a temperature sensor

40d between the temperature sensor 40c and the temperature sensor 40e. The partition 30' is the comparative example.

The three partitions below, each of which is a partition 30 according to

Embodiment 1, are further prepared. Regarding the partition 30 illustrated in section

(b) of Fig. 11, a graphite sheet 35 is provided on the entirety of a face of the plate 31

(equivalent to the partition 30 of section (a) of Fig. 10). Regarding the partition 30

illustrated in section (c) of Fig. 11, a graphite sheet 35 having a vertical length of L/2 is

provided from the upper end portion of the plate 31 (equivalent to the partition 30 of

section (c) of Fig. 10). Regarding the partition 30 illustrated in section (d) of Fig. 11, a

graphite sheet 35 having a vertical length of L/4 is provided from the upper end portion

of the plate 31 (equivalent to the partition 30 of section (b) of Fig. 10). As with the

partition 30', temperature sensors 40a, 40b, 40c, 40d, and 40e are arranged at each of

the partitions 30. Note that each of the graphite sheets 35 had a thickness of 40 Pm. Note that, hereinafter, the example of section (b) of Fig. 11 is referred to as

Example 1, the example of section (c) of Fig. 11 is referred to as Example 2, and the

example of section (d) of Fig. 11 is referred to as Example 3.

[0025]

Next, each of the above-described partitions 30 and 30'was mounted in the

refrigerator 100, the refrigerator 100 was energized, and the temperatures at

measurement points were measured by using the respective temperature sensors 40a,

40b,40c,40d, and 40e.

Regarding the test environment, pursuant to the Japanese Industrial Standards

(JIS9801), the refrigerator 100 is mounted in a thermo-hygrostat, an outside air

temperature was set to 32 degrees C, and a relative humidity was set to 70%R.H. The

duty cycle of the heater 32 was set to 40%.

Fig. 12 illustrates the lowest temperature of the plate 31 of each of the partitions

30 and 30' of the comparative example and Examples 1 to 3. Note that the lowest temperatures are given by differences in temperature when the lowest temperature of the comparative example is zero.

In each of the examples, the lowest temperature was a temperature measured by

the temperature sensor 40a disposed near the upper end portion of the plate 31. Note

that the upper end portion of the plate 31 had a temperature lower than the temperature

at the lower end portion because the temperature measured by the temperature sensor

40e disposed near the lower end portion of the plate 31 is affected by the heat

transferred from the heat transfer pipe 16a.

In comparison regarding the lowest temperature, the temperature of each of

Examples 1 to 3 was higher by 0.9 K or more than the temperature of the comparative

example. That is, in each of Examples 1 to 3, heat can efficiently be transferred to the

upper end portion of the plate 31. It is considered that this is because the heat

generated by the heater 32 is likely to diffuse in the direction parallel to the inside face

of the plate 31, and the heat of the heater 32 was sufficiently transferred to the upper

end portion of the plate 31.

In addition, in comparison between Examples 1 to 3, the lowest temperature of

each of Example 2 and Example 3 was higher than the lowest temperature of Example

1. That is, in each of Example 2 and Example 3, heat can more efficiently be

transferred to the upper end portion of the plate 31. It is considered that this is

because, in Example 1 in which the graphite sheet 35 is stuck to the entirety of a face of

the plate 31, the heat generated by the heater 32 is used to heat the entire face of the

plate 31 including the lower end portion and the central portion, whereas, in Examples 2

and 3, the heat of a portion of the heater 32 disposed in an upper region of the plate 31

is hardly transferred to the lower end portion or the central portion of the plate 31 and is

thus used to heat the upper end portion of the plate 31.

As described above, it can be considered that the partition 30 having the graphite

sheet 35, as in each of Examples 1 to 3, has high efficiency of thermal diffusion to the

upper end portion of the plate 31.

[0026]

Next, regarding each of the comparative example and Examples 1 to 3, Fig. 13

illustrates the result of calculating annual power consumption of the heater 32 based on

the lowest temperature measured as described above.

The power consumption of the heater 32 required to suppress condensation from

forming on the plate 31 depends on the lowest temperature of the plate 31. This is

because condensation is most likely to form on a portion at which a temperature is the

lowest. The lowest temperature of each of Examples 1 to 3 is higher than the lowest

temperature of the comparative example as described above, and a temperature at

which condensation does not form can thereby be maintained even when the duty cycle

of the heater 32 is lowered to reduce the power consumption of the heater 32. Thus, the values of the power consumption of Examples 1 to 3 are 87% to 89% relative to the

value of the power consumption of the comparative example, and the power

consumption can be reduced by 11% to 13%. Note that the power consumption given

here is calculated by using, as prescribed by JIS C9801-3, the probability of occurrence

of an annual air temperature and an annual humidity and the duty cycle of the heater 32

required to maintain the surface temperature of the plate at a temperature above the

dew-point at each air temperature and humidity.

In addition, because the lowest temperatures of Example 2 and Example 3 are

higher than the lowest temperature of Embodiment 1, power consumption can be

reduced more significantly in Example 2 and Example 3.

[0027]

As Examples 1 to 3 are described above, and, in particular, as the evaluation

results of Example 2 and Example 3 demonstrate, the heat generated by the heater 32

is efficiently transferred to an end portion of the plate 31 when the graphite sheet 35 is

in contact with a portion of the plate 31 around the end portion. Thus, in other

modifications of Embodiment 1 (the examples illustrated in Fig. 11), regarding the end

portion in a region, of the plate, to which the graphite sheet 35 is stuck, the temperature

of the end portion can also be increased more than the temperature of the end portion

of the comparative example.

[0028]

The refrigerator 100 according to Embodiment 1 of the present disclosure is

configured as described above and exhibits the following advantageous effects.

The refrigerator 100 includes the graphite sheet 35 having a thermal conductivity,

in the direction parallel to the inside face of the plate 31, higher than the thermal

conductivity thereof in the direction from the inside face toward the outside face of the

plate. The graphite sheet 35 is provided on the heater 32 and on a portion of the plate

31 around the end portion at which the heater 32 is not provided so as to transfer heat

to a region of the face of the plate 31 around the end portion of the plate 31. Thus, the

heat generated at the heater 32 is hardly transferred inside or outside the refrigerator

100 but is likely to be transferred, along the inside face of the plate 31, to a portion of

the plate 31 around the end portion at which a heater 32 is not provided. That is, in the

refrigerator (the comparative example) without a graphite sheet 35, the heat of the

heater 32 leaked inside or outside the refrigerator and was thus wasted, whereas the

refrigerator 100 enables effective use of such leaking heat by transferring the heat

toward the end portion. Thus, as Fig. 12 illustrates, the temperature of the vicinity of

the end portion of the plate 31 can be increased. Consequently, it is possible to reduce

the electric power required to prevent condensation from forming in the vicinity of the

end portion of the plate 31 and thus to reduce the power consumption of the heater 32.

[0029]

In addition, the refrigerator 100 includes the above-described graphite sheet 35,

and the heat around the heater 32 can thereby efficiently diffuse to the end portion of

the plate 31. Thus, the difference in temperature between a region of the plate 31

around the heater 32 and the end portion of the plate 31 can be reduced to keep the

temperature distribution of the plate 31 nearly uniform. Accordingly, the refrigerator

100 with high quality can be provided.

[0030]

The refrigerator 100 includes the graphite sheet 35 interposed between the

heater 32 and the inside face of the plate 31. Thus, the heat generated by the heater

32 is transferred to the plate 31 as it is and can be suppressed from leaking outside the

refrigerator 100.

[0031] The refrigerator 100 includes the graphite sheet 35 provided in a region of the

plate 31, in the longitudinal direction of the plate 31, closer to the end portion than to the

center of the plate 31. As described above, heat can efficiently diffuse to the end

portion of the plate 31, as Fig. 12 illustrates, by the graphite sheet 35 being provided

closer to the end portion of the plate 31 than to the center of the plate 31.

[0032]

The refrigerator 100 includes the heat transfer pipe 16a provided in the partition

plate 1c positioned between the refrigerator compartment 11 and the versatile

compartment 13 as well as the ice-making compartment, and the graphite sheet 35 is

provided, at one of the end portions of the plate 31, that is, a region of the inside face of

the plate 31 near the end portion being apart from the heat transfer pipe 16a. The end

portion, of the plate 31, near the heat transfer pipe 16a is likely to maintain a high

temperature due to the heat transferred from the heat transfer pipe 16a, whereas the

temperature of the end portion apart from the heat transfer pipe 16a is likely to

decrease. The graphite sheet 35 is provided in such a region of the end portion being

apart from the heat transfer pipe 16a, and heat can thereby be transferred to the end

portion that is more likely to be cooled. Thus, the power consumption of the heater 32

can be reduced.

[0033]

Regarding the refrigerator 100, the plate 31 has the flanges 36a and 36b

extending from the end portions of the plate 31 and provided for fixing the plate 31 to

the case 34. The flanges 36a and 36b extend toward the inside of the housing 1 and

are not provided with a heat insulator 33. Thus, the flanges 36a and 36b are likely to

be cooled by cold air, and the temperatures of the end portions, of the plate 31, having

the flanges 36a and 36b are more likely to decrease than the temperature of another

end portion. Regarding the refrigerator 100, the graphite sheet 35 is provided on a

portion of the plate 31 around each of the end portions having the flanges 36a and 36b,

and heat can thereby be transferred to the end portions that are more likely to be

cooled; thus, the power consumption of the heater 32 can be reduced.

[0034]

Here, modifications of the refrigerator 100 according to Embodiment 1 of the

present disclosure will be described, and a supplementary description will be given.

Regarding the refrigerator 100, the refrigerator compartment 11 is provided with

the double doors constituted by the doors 2 and 3. However, the door of the

refrigerator compartment 11 may be a drawer or a single-swing door. Instead of the

refrigerator compartment 11, the ice-making compartment, the versatile compartment

13, the freezer compartment 14, or the vegetable compartment 15 may be provided with

double doors. In such an instance, the double doors provided around the opening of the ice-making compartment, the versatile compartment 13, the freezer compartment

14, or the vegetable compartment 15 have the partition 30 of Embodiment 1.

[0035] Although the gap between the door 2 and the door 3 extends vertically in

Embodiment 1, the gap may extend laterally, and, in this instance, the door 2 and the

door 3 are arranged above and below the opening.

[0036] Although the configuration in which the graphite sheet 35 is interposed between

the plate 31 and the heater 32 is described in Embodiment 1, the heater 32 may

alternatively be interposed between the graphite sheet 35 and the plate 31. In this

instance, the graphite sheet 35 is pressed onto the heater 32 and the plate 31 from the

heat insulator 33 side to be deformed and is provided on the heater and the plate 31 so

as to transfer heat. Due to such a configuration, the graphite sheet 35 is interposed

between the heater 32 and the heat insulator 33, and the heater 32 and the heat

insulator 33 are not thereby in contact with one another. Thus, the heat generated by

the heater 32 is transferred to the heat insulator 33 as it i is and can be suppressed

from leaking inside the refrigerator 100.

[0037]

Although the example in which the heat transfer pipe 16a is disposed in the

vicinity of the lower end portion of the plate 31 is given in Embodiment 1, the heat

transfer pipe may alternatively be provided in the vicinity of the upper end portion of the plate 31, that is, inside the top plate 1a of the housing 1. In this instance, the partition 30 of section (d) of Fig. 11 or section (e) of Fig. 11 is preferably used.

[0038]

Embodiment 2

Next, Embodiment 2 of the present disclosure will be described. The description

of a portion similar to the constituent described in Embodiment 1 will be omitted, and a

portion differing from the constituent of Embodiment 1 will be described below. Note

that a refrigerator 100 of Embodiment 2 can be implemented in combination with the

modifications of Embodiment 1.

In Embodiment 1, because being formed by the plate 31 being bent, the flanges

36a and 36b are made of sheet metal.

In Embodiment 2, flanges 236a and 236b are made of a resin material.

[0039] As section (a) and section (b) of Fig. 14 illustrate, the refrigerator 100 of

Embodiment 2 includes the flanges 236a and 236b extending from the end portions of

the plate 31 toward the case 34 and made of a resin material. Such a resin material is

a material such as a polypropylene resin or an acrylonitrile resin that has thermal

conductivity lower than the thermal conductivity of sheet metal.

The plate 31 made of sheet metal and the flanges 236a and 236b made of a resin

material are different in material, and joint therebetween is enabled, for example, by

using adhesive, double-faced tape, or hot melt adhesive or by caulking, screwing, or

riveting, or by providing a hook claw.

[0040]

The refrigerator 100 according to Embodiment 2 of the present disclosure is

configured as described above and exhibits advantageous effects similar to the

advantageous effects exhibited by Embodiment 1 and further exhibits the following

advantageous effects.

The flanges 236a and 236b of the plate 31 of the refrigerator 100 are made of a

resin material, and the end portions of the plate 31 can thereby be suppressed from being cooled by the cold air inside the housing 1. Thus, the power consumption of the heater can be reduced.

Industrial Applicability

[0041] The refrigerator according to the present disclosure can be used for preserving a

stored object.

[0042]

It is to be understood that, if any prior art publication is referred to herein, such

reference does not constitute an admission that the publication forms a part of the

common general knowledge in the art, in Australia or any other country.

[0043]

In the claims which follow and in the preceding description of the invention, except

where the context requires otherwise due to express language or necessary implication,

the word "comprise" or variations such as "comprises" or "comprising" is used in an

inclusive sense, i.e. to specify the presence of the stated features but not to preclude the

presence or addition of further features in various embodiments of the invention.

Reference Signs List

[0044]

1: housing, 1a: top plate, 1b: bottom plate, 1c: partition plate, 1d: partition plate,

le: partition plate, 2: door, 3: door, 4: ice-making compartment drawer, 5: versatile

compartment drawer, 6: freezer compartment drawer, 7: vegetable compartment drawer,

11: refrigerator compartment, 13: versatile compartment, 14: freezer compartment, 15:

vegetable compartment, 16a: heat transfer pipe, 16b: heat transfer pipe, 16c: heat

transfer pipe, 20: cooling device, 21: compressor, 22: condenser, 23: expansion unit, 24:

evaporator, 25: fan, 26: defroster, 27: return air, 30: partition, 31: plate, 32: heater, 33:

heat insulator, 34: case, 35: graphite sheet, 35a: adhesive tape piece, 35b: adhesive

tape piece, 36a: flange, 36b: flange, 37a: gasket, 37b: gasket, 38a: throat, 38b: throat,

39a: inside of housing, 39b: outside of housing, 40a: temperature sensor, 40b:

temperature sensor, 40c: temperature sensor, 40d: temperature sensor, 40e:

temperature sensor, 230: partition, 236a: flange, 236b: flange

Claims (8)

1. A refrigerator including double doors, a plate having an outside face that closes a gap left between the double doors with the double doors being closed, and a heater that

is provided beside an inside face of the plate and heats the plate,

wherein the heater is spaced apart from an end portion of the plate,

the refrigerator further comprising a graphite sheet that transfers heat of the

heater to a region of the plate between an end portion of the plate and the heater, and

wherein the graphite sheet has a thermal conductivity, in a direction parallel to the

inside face, higher than a thermal conductivity thereof in a direction from the inside face

toward the outside face.

2. The refrigerator of claim 1, wherein the graphite sheet is provided between the heater and the inside face of

the plate.

3. The refrigerator of claim 1, further comprising

a heat insulator provided so as to cover the heater and the inside face of the

plate,

wherein the graphite sheet is provided between the heater and the heat insulator.

4. The refrigerator of any one of claims 1 to 3, wherein a longitudinal direction of the plate is parallel to a direction in which the

gap between the double doors extends, and

wherein the graphite sheet is provided in a region of the plate, in the longitudinal

direction of the plate, closer to an end portion than to a center of the plate so as to

transfer heat.

5. The refrigerator of any one of claims 1 to 4, further comprising

a housing having an opening that is closed with the double doors and the plate,

having a first space that communicates with an outside through the opening and stores an object to be stored, and having a second space that is arranged in parallel with the first space in a direction in which the gap extends and that cools a stored object at a temperature differing from a temperature at the first space, wherein the first space and the second space are separated from one another by a partition plate, the partition plate having a heat transfer pipe that heats the partition plate, and wherein the graphite sheet is provided in a region of the plate closer to an end portion of the plate apart from the heat transfer pipe than to an end portion of the plate beside the heat transfer pipe so as to transfer heat.

6. The refrigerator of any one of claims 1 to 5, further comprising

a case provided at a position at which the case faces the plate with the heater

interposed therebetween,

wherein the plate has, at at least an end portion, a flange extending toward the

case, wherein the plate is fixed to the case with the flange, and

wherein the graphite sheet is provided in a region of the inside face of the plate

between an end portion of the plate having the flange and the heater so as to transfer

heat.

7. The refrigerator of claim 6, wherein the plate is made of sheet metal, and the flange is made of a resin

material.

8. The refrigerator of any one of claims 1 to 3, wherein the graphite sheet is provided on an entirety of the inside face of the

plate so as to transfer heat.