U.S. patent application number 12/738096 was filed with the patent office on 2010-11-04 for refrigerator.
This patent application is currently assigned to BSH BOSCH UND SIEMENS HAUSGERA TE GMBH. Invention is credited to Stefan Holzer, Sandro Kohn, Dasaradh Kumar Patchala.
Application Number | 20100275640 12/738096 |
Document ID | / |
Family ID | 40458947 |
Filed Date | 2010-11-04 |
United States Patent
Application |
20100275640 |
Kind Code |
A1 |
Holzer; Stefan ; et
al. |
November 4, 2010 |
REFRIGERATOR
Abstract
A refrigerator including a refrigeration generator and an
insulated interior space. The insulated interior space may include
molded parts having a core comprising a porous insulating material
and an airtight envelope. An internal air pressure of the molded
parts is lowered relative to an ambient air pressure of the
refrigerator, and the insulating material may include a nanofoam
having a pore size of about 100 nanometers and less.
Inventors: |
Holzer; Stefan; (Aalen,
DE) ; Kohn; Sandro; (Bonn, DE) ; Patchala;
Dasaradh Kumar; (Neu-Ulm, DE) |
Correspondence
Address: |
BSH HOME APPLIANCES CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
100 BOSCH BOULEVARD
NEW BERN
NC
28562
US
|
Assignee: |
BSH BOSCH UND SIEMENS HAUSGERA TE
GMBH
Munich
DE
|
Family ID: |
40458947 |
Appl. No.: |
12/738096 |
Filed: |
October 8, 2008 |
PCT Filed: |
October 8, 2008 |
PCT NO: |
PCT/EP08/63445 |
371 Date: |
July 7, 2010 |
Current U.S.
Class: |
62/440 |
Current CPC
Class: |
F25D 23/063 20130101;
F25D 2201/14 20130101 |
Class at
Publication: |
62/440 |
International
Class: |
F25D 11/00 20060101
F25D011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 22, 2007 |
DE |
10 2007 050 403.0 |
Claims
1-9. (canceled)
10. A refrigerator, comprising: a refrigeration generator; and an
insulated interior space, the insulated interior space including
molded parts having a core comprising a porous insulating material
and an airtight envelope, wherein an internal air pressure of the
molded parts is lowered relative to an ambient air pressure of the
refrigerator, and wherein the insulating material includes a
nanofoam having a pore size of about 100 nanometers and less.
11. The refrigerator as claimed in claim 10, wherein the internal
air pressure of the molded parts is less than about 100 mbar.
12. The refrigerator as claimed in claim 10, wherein the molded
parts are structured as rectangular panels.
13. The refrigerator as claimed in claim 10, wherein a shape of the
molded parts is adapted to match a purpose of their
application.
14. The refrigerator as claimed in claim 10, wherein a molded part
of the molded parts that forms a base is structured in a stepped
shape.
15. The refrigerator as claimed in claim 10, wherein the molded
parts are joined to one another, and wherein the resulting joints
have a similar thermal conductivity as the molded parts.
16. The refrigerator as claimed in claim 10, wherein the internal
pressure of the molded parts is less than about 5 mbar.
17. The refrigerator as claimed in claim 10, wherein an envelope of
the molded parts includes a metallized multilayer film.
18. The refrigerator as claimed in claim 10, wherein the porous
insulating material for the core of the molded parts has a pore
size of less than about 50 nanometers.
Description
[0001] The invention relates to a refrigerator according to the
pre-characterizing clause of claim 1.
[0002] So-called vacuum panels have become known for different
insulation purposes. These vacuum panels typically consist of an
airtight outer skin which encloses a core consisting of porous
insulating material. Silica or aerogels, but also open-cell foams
made of polyurethane, are often used as insulating material. Said
panels are evacuated and sealed. In this process the internal
pressure is reduced to a value of less than 100 mbar. As a result
of the evacuation the rigidity and stability of the panels is
increased on the one hand, while on the other hand the insulation
effect is reinforced. This effect can be explained in that the
probability of collisions of the air molecules present in the pores
is reduced. Depending on the core material used and the internal
pressure, such vacuum panels possess a thermal conductivity in a
range of 0.017 to 0.025 W/mK.
[0003] In the meantime materials called nanofoams with a pore size
lying in the nanometer range have also become known, in particular
for building insulation. These nanofoams are fabricated from
plastic by way of synthesis. They achieve a thermal conductivity in
the range of 0.010 to 0.015 W/mK and so lie far below the values of
vacuum panels.
[0004] Present-day refrigeration appliances such as e.g.
refrigerators, freezers or refrigerator/freezer combinations
typically consist of an inner shell which is fixed in an outer
housing consisting of lid, base, side walls and rear wall. After
the refrigeration generator and the electrical components have been
installed, the interspace between inner shell and outer housing is
foamed in place. This method is relatively complex and therefore
expensive.
[0005] Transportable refrigerator boxes of smaller size are already
often manufactured more cheaply. Prefabricated vacuum panels which
are assembled to form a corresponding housing are used to build
said refrigerator boxes. Such vacuum panels must be relatively
thick in order to achieve the necessary insulation. The ratio of
internal to external volume is therefore unfavorable.
[0006] The object underlying the invention is to construct a
refrigerator in such a way that it can be manufactured
cost-effectively and at the same time a very good ratio of internal
to external volume exists. This notwithstanding, it is also aimed
to improve the insulating effect in comparison with conventional
refrigerators or at least maintain it at an equal level.
[0007] The object is achieved by means of a refrigerator having the
features recited in claim 1. According to the invention molded
parts having a core consisting of nanofoam are used to insulate the
interior space. The pore size of the nanofoam is less than 100
nanometers. The core is surrounded by an airtight envelope. The
molded part is evacuated such that the internal pressure amounts to
less than 100 mbar. Said molded parts can be joined together to
form a housing and thereby delimit the interior space of the
refrigerator. Equally, however, they can be mounted onto the
outside of a housing and in this way form the insulation of the
interior space.
[0008] In a first exemplary embodiment the molded parts are
implemented as rectangular panels. Such panels can be manufactured
cheaply and with high precision. By means of such panels a housing
for a refrigerator can be easily constructed and assembled with
little effort and at little cost.
[0009] In a further exemplary embodiment the shape of the molded
part is adapted to suit the purpose of the particular application.
Thus, for example, recesses for receiving shelf supports can be
integrated into the molded parts. Similarly it is possible for a
molded part to have a different thickness so that e.g. a freezer
compartment can be integrated in the upper section of the
refrigerator and the insulating effect in this region can be
reinforced.
[0010] The molded part forming the base is advantageously embodied
in a stepped shape. At the rear of the refrigerator there is thus
created a machine bay which is accessible from the rear and in
which the compressor, for example, can be housed. A similar
structure can be achieved if instead of the base the rear wall is
embodied in a stepped shape. In this way also the machine bay can
be implemented using simple means.
[0011] According to the invention the molded parts are joined to
one another in such a way that the joins have a similar thermal
conductivity to the molded parts themselves. By this means thermal
bridges are prevented at the joining edges of the individual molded
parts. Affected by this in particular are the joins between the
rear wall and the molded parts adjacent thereto which form the lid
and the base, as well as the two side walls. Since the condenser,
which has a high level of heat emission, is usually fixed to the
rear wall, no thermal bridge into the refrigerated interior space
of the refrigerator must exist, in particular at the borders of the
rear wall.
[0012] In order to be able to ensure the lowest possible heat
conductance value of the molded parts, their internal pressure
advantageously amounts to less than 5 mbar. Particularly
advantageously the internal pressure lies between 1 and 3 mbar.
[0013] In practice the internal pressure of the molded part that is
relevant for the thermal conductivity cannot be kept constant. This
means that at least over the course of several years the original
internal pressure increases due to the diffusion of water vapor and
air through the envelope of the molded part. In order to keep this
increase to an absolute minimum, a metallized multilayer film is
used for the envelope of the molded part.
[0014] The insulating material of the core advantageously has a
pore size of less than 50 nanometers. Particularly advantageously
the nanofoam has pores in the size range between 1 and 100
nanometers. At this small pore size the probability of collisions
between air molecules is reduced to such a degree that even if
there is a rise in the internal pressure the thermal conductivity
will increase only to a small extent. In this way the refrigerator
maintains an outstanding insulation capacity over its entire useful
life.
[0015] Further details and advantages of the invention will emerge
from the dependent claims in connection with the description of an
exemplary embodiment which is explained in greater detail with
reference to the drawing, in which:
[0016] FIG. 1 shows a side view of a refrigerator according to the
invention with cutaway side wall.
[0017] FIG. 1 shows a refrigerator 1 whose interior space 8 is
delimited by two side walls 2, a base 4, a lid 5 and a rear wall 3.
The opening on the front side is closed by means of the door 6. The
side walls 2, the base 4, the lid 5 and the rear wall 3 consist of
molded parts, with side walls 2, lid 5 and rear wall 3 being
embodied in the shape of panels. In the base 4, in contrast, a step
is formed.
[0018] The core of the molded parts consists of a porous insulating
foam, called nanofoam. This open-cell insulating foam consisting of
polyurethane has a pore size lying in the nanometer range, ideally
around 1-10 nanometers. All the molded parts have an airtight and
waterproof envelope. This consists of a metallized multilayer film.
The molded parts are evacuated to an internal pressure of ideally
1-3 mbar. The metallized multilayer film can almost totally prevent
the diffusion of water vapor and air into the molded part, with the
result that said internal pressure is maintained for a long time.
This film also prevents the formation of thermal bridges at the
abutting edges of molded parts placed against one another, such
that no heat can penetrate into the insulated interior space 8 at
these points either.
[0019] The molded parts are joined together at the factory to form
a housing in such a way that heat from outside likewise cannot
reach the interior space as a result of the joining technology.
This can be achieved for example by means of certain adhesives
which contain no or only few heat-conducting materials.
[0020] In the exemplary embodiment shown the rear wall 3 is
inserted between the lid 5 and the base 4. The side walls 2 are
attached below the lid 5 but overlap the base 4 and the rear wall
3. In this way smooth, continuous side surfaces are produced
against which only the lid 5 visually abuts. The side walls 2 also
form the lateral delimiting surfaces for the machine bay 7. A
uniform, easy-to-maintain surface is produced, also when viewed
from above.
[0021] The interior space 8 delimited by the molded parts 2, 3, 4,
5 is closed by means of the door 6. The latter rests on the frame
formed from the narrow sides of the molded parts 2, 4, 5. In this
way an attractive, smooth front side is produced.
[0022] During the assembly of the refrigerator the narrow side of
one molded part is in each case joined to the surface of another
molded part. Thus, for example, a rear strip of the surface of the
base 4 is joined to the bottom narrow side of the rear wall 3,
while the two lateral narrow sides of the base 4 are joined to
areas of the inner surfaces of the side parts 2.
[0023] The interior space 8 can, of course, also be lined with a
one-piece inner shell such that the interior space has no grooves
or gaps of any kind and can be cleaned easily. Similarly an outer
shell can also be provided for design reasons or in order to
increase stability, with the result that the refrigerator takes on
the appearance of a conventional refrigerator.
List of reference signs
[0024] 1 Refrigerator [0025] 2 Side wall [0026] 3 Rear wall [0027]
4 Base part [0028] 5 Lid [0029] 6 Door [0030] 7 Machine bay [0031]
8 Interior space
* * * * *