U.S. patent application number 15/318984 was filed with the patent office on 2017-05-04 for vacuum damping element with a thermoelectric element.
The applicant listed for this patent is LIEBHERR-HAUSGERATE LIENZ GMBH, LIEBHERR-HAUSGERATE OCHSENHAUSEN GMBH. Invention is credited to Michael Freitag, Jochen Hiemeyer, Martin Kerstner.
Application Number | 20170122627 15/318984 |
Document ID | / |
Family ID | 54706800 |
Filed Date | 2017-05-04 |
United States Patent
Application |
20170122627 |
Kind Code |
A1 |
Kerstner; Martin ; et
al. |
May 4, 2017 |
Vacuum Damping Element With A Thermoelectric Element
Abstract
The invention relates to a vacuum damping element (1) with a
casing (2) which defines a vacuum region. A thermoelectric element
(3), in particular a Peltier element (3), is arranged within the
vacuum region in order to generate a temperature difference between
two regions (5) provided on the outside of the casing (2).
Inventors: |
Kerstner; Martin; (Wurzburg,
DE) ; Freitag; Michael; (Wurzburg, DE) ;
Hiemeyer; Jochen; (Karlstadt, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LIEBHERR-HAUSGERATE LIENZ GMBH
LIEBHERR-HAUSGERATE OCHSENHAUSEN GMBH |
Lienz
Ochsenhausen |
|
AT
DE |
|
|
Family ID: |
54706800 |
Appl. No.: |
15/318984 |
Filed: |
June 11, 2015 |
PCT Filed: |
June 11, 2015 |
PCT NO: |
PCT/EP2015/001183 |
371 Date: |
December 15, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25D 23/065 20130101;
F25B 21/02 20130101; F25B 21/04 20130101; F25B 2321/025 20130101;
F25B 2321/0252 20130101; F25D 2201/14 20130101; F25B 2321/023
20130101 |
International
Class: |
F25B 21/04 20060101
F25B021/04; F25D 23/06 20060101 F25D023/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 16, 2014 |
DE |
10 2014 008 668.2 |
Jan 20, 2015 |
DE |
10 2015 000 553.7 |
Jan 29, 2015 |
DE |
10 2015 001 060.3 |
Jan 29, 2015 |
DE |
10 2015 001 142.1 |
Feb 2, 2015 |
DE |
10 2015 001 281.9 |
Feb 3, 2015 |
DE |
10 2015 001 380.7 |
May 20, 2015 |
DE |
10 2015 006 561.0 |
Claims
1. A vacuum insulation body having an envelope which defines a
vacuum zone, characterized in that a thermoelectric element, in
particular a Peltier element is arranged within the vacuum zone to
generate a temperature difference between two zones provided at the
outside of the envelope.
2. A vacuum insulation body in accordance with claim 1,
characterized in that the thermoelectric element has a
substantially plate-like basic shape and two thermal surfaces which
preferably extend approximately in parallel with one another and
are spaced apart from one another.
3. A vacuum insulation body in accordance with claim 1,
characterized in that a thermoconductive body arranged in the
vacuum zone is furthermore provided which is in heat-transferring,
in particular in thermoconductive contact or in direct contact with
the thermoelectric element and the envelope.
4. A vacuum insulation body in accordance with claim 3, wherein a
contact surface between the thermoconductive body and the envelope
is larger than a contact surface between the thermoconductive body
and the thermoelectric element.
5. A vacuum insulation body in accordance with claim 1, furthermore
having a heat exchanger which is arranged outside the vacuum zone,
wherein the heat exchanger is thermally coupled to a region of the
envelope, preferably in a region whose temperature can be
influenced by the thermoelectric element.
6. A vacuum insulation body in accordance with claim 1,
characterized in that the envelope comprises a high barrier film or
is a high barrier film; and/or in that a core material, in
particular Pearlite, is located in the vacuum zone.
7. A vacuum insulation body in accordance with claim 5,
characterized in that the heat exchanger itself represents a part
of the envelope or the total envelope.
8. A thermoelectric element, in particular a Peltier element,
comprising: at least one n-doped semiconductor element; and at
least one p-doped semiconductor element that is connected to the
n-doped semiconductor element via a conductor bridge, wherein the
two semiconductor elements are spaced apart from one another such
that a free space is formed between them, characterized in that the
free space between the n-doped semiconductor material and the
p-doped semiconductor material is filled with a material in powder
form, with provision preferably being made that the material in
powder form has a mean grain size of a powder grain which is
between 5 .mu.m and 30 .mu.m, preferably between 10 .mu.m and 25
.mu.m, and particularly preferably between 15 .mu.m and 20
.mu.m.
9. A vacuum insulation body having an envelope which defines a
vacuum zone, characterized in that a thermoelectric element, in
particular a Peltier element is arranged within the vacuum zone to
generate a temperature difference between two zones provided at the
outside of the envelope, characterized in that the thermoelectric
element is configured in accordance with claim 8; and in that the
material in powder form is preferably simultaneously a core
material of the vacuum insulation body.
10. A thermally insulated container having at least one carcass and
having at least one temperature-controlled inner space, preferably
a refrigerator unit and/or a freezer unit having at least one
carcass and having at least one refrigerated inner space which is
surrounded by the carcass, as well as having at least one closing
element by means of which the temperature-controlled inner space
and preferably the refrigerated inner space is closable, wherein at
least one intermediate space is present between the
temperature-controlled inner space and preferably the refrigerated
inner space and the outer wall of the container and preferably of
the unit, characterized in that at least one vacuum insulation body
in accordance with claim 1 is arranged in the intermediate
space.
11. A thermally insulated container having at least one carcass and
having at least one temperature-controlled inner space, preferably
a refrigerator unit and/or a freezer unit having at least one
carcass and having at least one refrigerated inner space which is
surrounded by the carcass, as well as having at least one closing
element by means of which the temperature-controlled inner space
and preferably the refrigerated inner space is closable, wherein at
least one intermediate space is present between the
temperature-controlled inner space and preferably the refrigerated
inner space and the outer wall of the container and preferably of
the unit, characterized in that a thermoelectric element in
accordance with claim 8 is arranged in the intermediate space.
Description
[0001] The present invention relates to a vacuum insulation body
comprising a thermoelectric element which is preferably configured
as a Peltier element and which is preferably used in refrigerator
units and/or freezer units.
[0002] With refrigerator units and/or freezer units, a vacuum
insulating body is arranged in the region between the outer jacket
of the unit and the inner container to be cooled to achieve a
sufficiently high thermal insulation between the outside and the
inside of the unit to be insulated by means of the principle of
vacuum thermal insulation.
[0003] Thermoelectric elements, in particular Peltier elements, are
elements which can generate a temperature drop with the aid of
electrical energy. The Peltier element comprises two or more small
cuboids which are made up of p-doped and n-doped semiconductor
materials and are connected to one another alternatingly at the top
and bottom by metallic bridges. The cuboids are connected to one
another such that serial connection is made in which differently
doped semiconductor materials are arranged alternately.
[0004] The thermoelectric elements, however, have a comparatively
small efficiency or a small capacity, which has the result that
Peltier elements have no extensive use in the cooling of
refrigerator units and/or freezer units. Thermoelectric elements
are only used sporadically in the field of coolers in which no
large temperature difference is required. The use of thermoelectric
elements in the field of refrigerating technology is therefore
restricted to special cases.
[0005] Due to the insulation becoming better and better, however,
and due to the reduced cooling power required for cooling which
results therefrom, thermoelectric elements, in particular Peltier
elements are becoming an interesting alternative.
[0006] On a simultaneous use of a vacuum insulation and a
thermoelectric element, however, the problem arises of effectively
integrating the two components. This problem stems from the fact
that the cold generation and the heat generation of a
thermoelectric element naturally take place directly next to one
another so that the use of the thermoelectric element can only be
carried out with the aid of a large hole through the vacuum
insulation. This results in a reduced insulation performance and in
a complicated design of the vacuum insulation and the
thermoelectric element.
[0007] These considerations are, however, by no means restricted to
refrigerator units and/or freezer units, but also apply to
thermally insulated containers in general. Thermally insulated
containers subject to these considerations have at least one
temperature-controlled inner space, with this being able to be
cooled or heated so that a temperature results in the inner space
below or above the ambient temperature of e.g. 21.degree. C.
[0008] It is the object of the present invention to eliminate the
above problems and to provide an efficient use of a combination of
thermoelectric element and vacuum insulation which has a
comparatively simple design.
[0009] This object is achieved by a vacuum insulation body having
the features of claim 1.
[0010] The vacuum insulation body accordingly has at least one
envelope which defines at least one vacuum zone. At least one
thermoelectric element is located within the vacuum zone to
generate a temperature difference between two zones provided at the
outside of the envelope.
[0011] The at least one thermoelectric element is thus preferably
located completely within the vacuum zone of the vacuum body so
that openings in the envelope of the vacuum insulation body for the
heat dissipation and heat supply from/to the thermoelectric element
can preferably be omitted.
[0012] A preferably diffusion-tight envelope or film is required to
provide a vacuum insulation body in which a vacuum is present. In
this respect, a core material can be provided in the vacuum zone
that provides the vacuum insulation body with the corresponding
shape stability and that simultaneously prevents the walls of the
envelope directly contacting one another after the generation of a
vacuum.
[0013] Since the thermoelectric element is provided in the vacuum
zone, the typically large opening of the vacuum insulation is
avoided which was conventionally provided by a thermoelectric
element in the refrigeration. A particularly advantageous
insulation performance of an inner space bounded by the vacuum
insulation body and a very space-saving and structured arrangement
of the two components result from this arrangement.
[0014] The arrangement of the thermoelectric element in the vacuum
zone provides that a corresponding temperature gradient is present
for orienting the thermoelectric element on an operation of the
thermoelectric element at the outside of the envelope. This means
that, depending on the hot or cold surface of the thermoelectric
element, the zones of the envelope facing the hot or cold surface
adopt a corresponding temperature. Two different temperature levels
are thus present at two different points (zones) of the outside of
the envelope which are caused by the thermoelectric element or can
be caused by it.
[0015] The arrangement of the thermoelectric element within the
vacuum zone also brings about the advantage that it is protected
from external influences. Sealing measures for preventing
condensation at the cold point of the thermoelectric element or
Peltier element can in particular be dispensed with.
[0016] The thermoelectric element preferably has a substantially
plate-like basic shape, with the thermoelectric element having two
thermal surfaces which preferably extend approximately in parallel
with one another and are spaced apart.
[0017] In accordance with a further advantageous feature of the
invention, the vacuum insulation body has at least one heat
conductive body arranged in the vacuum zone. It is in
heat-transferring, preferably thermoconductive, contact with the
thermoelectric element and with the envelope. The thermoconductive
body is in direct or indirect contact with the thermoconductive
body and/or with the envelope.
[0018] A "thermoconductive body" or a "heat exchanger" is
understood within the framework of the present invention as any
desired element with which heat can be transferred, with this heat
transfer inter alia comprising the heat conduction, but not being
restricted thereto.
[0019] The named thermoconductive body advantageously has a thermal
conductivity .lamda. of at least 3 W/m*K). The thermal conductivity
.lamda. of the thermoconductive body is preferably at least 10
W/(m*K), preferably at least 75 W/(m*K), and particularly
preferably at least 150 W/m*K).
[0020] It is possible in accordance with the invention to bring the
thermoelectric element arranged in the vacuum zone in an effective
thermal (direct or indirect) contact with the envelope. The
thermoconductive body in this respect provides a good thermal
coupling of the Peltier element or of the thermoelectric element
and the envelope since the heat exchange via convection in a
vacuumed zone is only possible in a slowed down manner or is not
possible at all.
[0021] On a transport of the heat generated and/or removed at the
cold surface and at the waste heat surface of the thermoelectric
element through the envelope of the vacuum insulation body, the
envelope represents a significant thermal resistance, independent
of its thickness, which has to be overcome.
[0022] It is expedient in this respect to provide the
thermoconductive body (also called the "primary heat exchanger" in
the following), in addition to the thermoelectric element, such
that its contact surface with the envelope is larger than its
contact surface with the thermoelectric element. This has the
result that the transfer surface at the envelope is much larger
than the transfer surface of the thermoelectric element at the
thermoconductive body and the temperature dropping over the
envelope is reduced to an acceptable degree. The smaller
temperature difference which is present at the two sides of the
envelope due to the specific design of the thermoconductive body
produces smaller losses at the envelope overall.
[0023] The thermoconductive body or bodies is/are preferably
arranged within the vacuum zone.
[0024] A fixing of the thermoelectric element or elements and of
the thermoconductive body or bodies, which are attached within the
vacuum zone, preferably takes place with the help of the envelope
itself which has a specific pressure which is applied from the
outside due to its vacuumed state and said pressure can be used to
fix the elements arranged in the vacuum zone. A partial vacuum
arises due to the vacuum present in the vacuum zone which can be
sufficiently large to achieve a layering of the thermoelectric
element with the thermoconductive body without the contact or
adhesive bonding with a substance capable of good thermal
conductivity typical for a thermoconductive body being necessary.
It is therefore not necessary to provide a further element between
the envelope and the Peltier element and/or the thermoconductive
body or between the envelope and the thermoconductive body that
reduces the thermal conductivity.
[0025] Provision is made in accordance with a preferred embodiment
that the thermoelectric element is clamped between the solid bodies
which form the primary heat exchanger.
[0026] Provision is preferably made in this respect that the
connection element or elements which connects/connect the solid
bodies has/have a small thermal conductivity so that no significant
heat bridge is produced. It is conceivable to use screws as the
connection element or connection elements. It is also possible to
use a part such as an injection molded part as a connection element
or as connection elements that is fastened to a molded part and
that latches at another molded part on assembly.
[0027] Provision is made in an embodiment that no adhesive is
provided between the thermoconductive body or bodies and the inside
of the film.
[0028] However, the case is generally also covered by the invention
that means promoting the heat transfer, in particular a substance
with thermal conductivity e.g. in the form of an adhesive bond, are
present between the thermoelectric element and the thermoconductive
body or bodies.
[0029] Provision is made in an embodiment that the thermoelectric
element and the thermoconductive body are connected to one another
using an adhesive connection. Provision is preferably made in this
respect that an adhesive having a comparatively high thermal
conductivity is used, for example an adhesive in which adhesive
compound fillers of good heat conductivity are present. Such an
adhesive can also be used for other adhesive connections used
within the framework of the present invention.
[0030] In accordance with a further advantageous optional feature
of the invention, the vacuum insulation body furthermore has at
least one heat exchanger (also called a "secondary heat exchanger"
in the following) that is arranged outside the vacuum zone, that is
at the outside of the envelope. The secondary heat exchanger is
thermally coupled to region of the envelope that is preferably the
region whose temperature can be influenced by the thermoelectric
element. Thermally coupled includes the possibility of a direct
contact or of a thermal contact.
[0031] Provision is preferably made that the thermoconductive body
or bodies are connected to the inside of the film and are not in
direct contact with the secondary heat exchanger. The heat exchange
in this case takes place through the film. This embodiment can be
advantageous for technical production reasons as well as for
reasons of vacuum tightness. It is conceivable that the thickness
of the film in the contact region of the thermoconductive body or
bodies is/are reduced with respect to the other regions to ensure a
better heat exchange. Alternatively, the thickness of the film can,
however, also be unchanged in these regions, which in turn can be
advantageous for technical production reasons as well as for
reasons of vacuum tightness.
[0032] Provision can alternatively be made that the
thermoconductive body or bodies is/are in direct contact with the
secondary heat exchanger and that cutouts are provided in the film
of the envelope in the region of the thermoconductive body or
bodies. The thermal conduction can thus be optimized.
[0033] The secondary heat exchanger can e.g. be connected to the
outer film side by means of a thermoconductive paste or by a
thermoconductive adhesive.
[0034] Provision is made in a preferred embodiment that a thin
graphite film is arranged at one side as a coupling element for the
mechanical relief of the thermoelectric element in the production
process, with the thermoelectric element being fixed by clamping
between the two solid bodies via the connection elements. At the
other side, the thermoconductive adhesive is also used to
compensate production tolerances in the thicknesses of the
thermoelectric element, the solid bodies and the connection
elements. The graphite film is preferably used at the hot side
since the higher heat flows flow here and the heat transfer
resistance through the thin graphite film is typically smaller than
the thermoconductive adhesive layer somewhat thicker due to
tolerance compensation.
[0035] The secondary heat exchanger or heat exchangers are
preferably arranged such that a direct or indirect heat exchange
takes place from or to the primary heat exchanger.
[0036] The envelope preferably comprises a high barrier film or is
a high barrier film which terminates the vacuum zone formed by the
envelope in a vacuum-tight manner.
[0037] A vacuum-tight or diffusion-tight envelope or a vacuum-tight
or diffusion-tight connection or the term high barrier film is
preferably understood as an envelope or as a connection or as a
film by means of which the gas input into the vacuum insulation
body is reduced so much that the increase in the thermal
conductivity of the vacuum insulation body caused by gas input is
sufficiently low over its service life. A time period of 15 years,
preferably of 20 years, and particularly preferably of 30 years, is
to be considered as the service life, for example. The increase in
the thermal conductivity of the vacuum insulation body caused by
gas input is preferably<100%, and particularly
preferably<50%, over its service life.
[0038] The surface-specific gas permeation rate of the envelope or
of the connection or of the high barrier film is preferably<10-5
mbar * I/s *m.sup.2 and particularly preferably<10-6 mbar * I/s
*m.sup.2 (measured according to ASTM D-3985). This gas permeation
rate applies to nitrogen and to oxygen. There are likewise low gas
permeation rates for other types of gas (in particular steam),
preferably in the range from<10-2 mbar * I/s * m.sup.2 and
particularly preferably in the range from<10-3 mbar * I/s *
m.sup.2 (measured according to ASTM F-1249-90). The aforesaid small
increases in the thermal conductivity are preferably achieved by
these small gas permeation rates.
[0039] An enveloping system known from the sector of vacuum panels
are so-called high barrier films. Single-layer or multilayer films
(which are preferably able to be sealed) having one or more barrier
layers (typically metal layers or oxide layers, with aluminum and
an aluminum oxide preferably being used as the metal or oxide
respectively) are preferably understood by this within the
framework of the present invention which satisfy the above-named
demands (increase in thermal conductivity and/or surface-specific
gas permeation rate) as a barrier to the gas input.
[0040] The above-named values or the make-up of the high barrier
film are exemplary, preferred values which do not restrict the
invention.
[0041] In a further advantageous embodiment of the invention, the
at least one thermoconductive body and/or one heat exchanger, i.e.
the primary and/or the secondary heat exchanger, is/are
itself/themselves a part of the envelope or forms the total
envelope. It is of advantage in this respect that, on the emission
of the temperature difference generated by the thermoelectric
element, a thermal resistance which is brought about by the
envelope does not have to be overcome.
[0042] If the primary or secondary heat exchanger forms a part of
the envelope, the heat exchangers (primary and secondary) can be
directly in contact with one another, which brings along the
advantage that the thermal resistance of the film does not have to
be overcome.
[0043] The vacuum insulation body furthermore preferably comprises
a core material that is present within the vacuum zone and that is
arranged between the individual semiconductor elements of the
thermoelectric element.
[0044] The skilled person knows that a thermoelectric element
(Peltier element) comprises a plurality of differently doped
semiconductor elements arranged next to one another in a grid-like
manner. In this respect, the respective semiconductor elements are
spaced apart from one another, with a core material being provided
in this region in accordance with an optional feature of this
invention.
[0045] The core material is therefore inserted into the region
between the semiconductor pellets of the Peltier element. The gas
heat conduction and the radiation heat exchange whose importance in
the transfer of temperature increases in a vacuumed state with an
increasing purity of the vacuum is thereby effectively suppressed
between the hot and cold side of the thermoelectric element.
Overall, this results in an increase in performance of the
thermoelectric element, whereby a more resource-efficient cooling
or heating is possible.
[0046] In addition, the present invention describes a
thermoelectric element that comprises at least one n-doped
semiconductor element and at least one p-doped semiconductor
element. The p-doped semiconductor element is connected via a
conductor bridge to the n-doped semiconductor element, with the two
semiconductor elements being spaced apart from one another so that
a free space is formed between them. The thermoelectric element in
accordance with the invention is characterized in that the free
space between the p-doped semiconductor element and the n-doped
semiconductor element is filled with a material in powder form.
[0047] The material in powder form preferably has a mean grain size
in which a powder grain is between 5 .mu.m and 30 .mu.m, preferably
between 10 .mu.m and 25 .mu.m, and particularly preferably between
15 .mu.m and 20 .mu.m.
[0048] Another name for the differently doped semiconductor
elements of the thermoelectric element is semiconductor pellets.
The material in powder form inserted between the space of the
semiconductor pellets prevents convection between the hot surface
and the cold surface of the thermoelectric element. The
effectiveness of the thermoelectric element can thus be
increased.
[0049] The present invention furthermore relates to a vacuum
insulation body in accordance with one of the above-described
variants in which the thermoelectric element has a material in
powder form in the free space between the differently doped
semiconductor elements. This material in powder form is in this
respect simultaneously also a core material for the vacuum
insulation body. Not only the performance capability of the
thermoelectric element can thus be increased, but rather the
advantages associated with the core material can also
simultaneously be achieved. An encapsulation of the thermoelectric
element from the core material is not necessary in this respect due
to the material identity.
[0050] In addition, the present invention relates to a thermally
insulated container having at least one carcass and having at least
one temperature-controlled inner space, preferably to a
refrigerator unit and/or freezer unit having at least one carcass
and having at least one refrigerated inner space which is
surrounded by the carcass as well as having at least one closing
element by means of which the temperature-controlled and preferably
the refrigerated inner space can be closed. At least one
intermediate space in which at least one vacuum insulation body in
accordance with the invention and/or a thermoelectric element in
accordance with the invention is located between the
temperature-controlled and preferably the refrigerated inner space
and the outer wall of the container and preferably of the unit.
[0051] The vacuum insulation body can be located between the
outside of the carcass in the inner container and/or between the
outside and the inside of the door or of another closing
element.
[0052] In a preferred embodiment of the container in accordance
with the invention and preferably of the refrigerator unit and/or
freezer unit in accordance with the invention, it is partly or
completely insulated with the help of a full vacuum system. It is
in this respect an arrangement whose thermal insulation between the
outside and the inner space at the carcass and/or at the closing
element only or primarily comprises an evacuated element, in
particular in the form of the envelope of vacuum-tight film or high
barrier film with a core material. The full vacuum insulation is
preferably formed by one or more vacuum insulation bodies in
accordance with the invention. A further thermal insulation by an
insulating foam and/or by vacuum insulation panels or by another
means for thermal insulation between the inside and the outside of
the unit is preferably not provided.
[0053] This preferred form of thermal insulation in the form of a
full vacuum system can extend between the wall bounding the inner
space and the outer skin of the carcass and/or between the inner
side and the outer side of the closing element such as a door,
flap, lid, or the like.
[0054] The full vacuum system can be obtained such that an envelope
of a gas-tight film is filled with a core material and is
subsequently sealed in a vacuum-tight manner. In an embodiment,
both the filling and the vacuum-tight sealing of the envelope take
place at normal or ambient pressure. The evacuation then takes
place by the connection to a vacuum pump of a suitable interface
worked into the envelope, for example an evacuation stub which can
have a valve. Normal or ambient pressure is preferably present
outside the envelope during the evacuation. In this embodiment, it
is preferably not necessary at any time of the manufacture to
introduce the envelope into a vacuum chamber. A vacuum chamber can
be dispensed with in an embodiment to this extent during the
manufacture of the vacuum insulation.
[0055] The temperature-controlled inner space is either cooled or
heated depending on the type of the unit (cooling appliance,
heating cabinet, etc.).
[0056] Provision is made in an embodiment that the container in
accordance with the invention is a refrigerator unit and/or a
freezer unit, in particular a domestic appliance or a commercial
refrigerator. Such units are, for example, covered which are
designed for a stationary arrangement at a home, in a hotel room,
in a commercial kitchen or in a bar. It can, for example, be a wine
cooler. Chest refrigerators and/or freezers are furthermore also
covered by the invention. The units in accordance with the
invention can have an interface for connection to a power supply,
in particular to a domestic mains supply (e.g. a plug) and/or can
have a standing aid or installation aid such as adjustment feet or
an interface for fixing within a furniture niche. The unit can, for
example, be a built-in unit or also a stand-alone unit.
[0057] In an embodiment, the container or the unit is configured
such that it can be operated at an AC voltage such as a domestic
mains voltage of e.g. 120 V and 60 Hz or of 230 V and 50 Hz. In an
alternative embodiment, the container or the unit is configured
such that it can be operated with DC current of a voltage of, for
example, 5 V, 12 V or 24 V. Provision can be made in this
embodiment that a plug-in power supply is provided inside or
outside the unit via which the unit is operated. An advantage of
the use of thermoelectric heat pumps in this embodiment is that the
whole EMC problem only occurs at the power pack.
[0058] Provision can in particular be made that the refrigerator
unit and/or freezer unit has a cabinet-type design and has a useful
space which is accessible to a user at its front side (at the upper
side in the case of a chest). The useful space can be divided into
a plurality of compartments which are all operated at the same
temperature or at different temperatures. Alternatively, only one
compartment can be provided. Storage aids such as trays, drawers or
bottle-holders (also dividers in the case of a chest) can also be
provided within the useful space or within a compartment to ensure
an ideal storage of refrigerated goods or frozen goods and an ideal
use of the space.
[0059] The useful space can be closed by at least one door
pivotable about a vertical axis. In the case of a chest, a lid
pivotable about a horizontal axis or a sliding cover is conceivable
as the closing element. The door or another closing element can be
connected in a substantially airtight manner to the carcass by a
peripheral magnetic seal in the closed state. The door or another
closing element is preferably also thermally insulated, with the
thermal insulation being able to be achieved by a foaming and
optionally by vacuum insulation panels or also preferably by a
vacuum system and particularly preferably by a full vacuum system.
Door storage areas can optionally be provided at the inside of the
door in order also to be able to store refrigerated goods
there.
[0060] It can be a small appliance in an embodiment. In such units,
the useful space defined by the inner wall of the container has,
for example, a volume of less than 0.5 m.sup.3, less than 0.4
m.sup.3 or less than 0.3 m.sup.3.
[0061] The outer dimensions of the container or unit are preferably
in the range up to 1 m with respect to the height, width and
depth.
[0062] The invention is, however, not restricted to refrigerator
units and/or freezer units, but rather generally applies to units
having a temperature-controlled inner space, for example also to
heat cabinets or heat chests.
[0063] Further particulars and details will be explained with
reference to the following description of the Figures. There is
shown:
[0064] FIG. 1: a cross-sectional view of a vacuum insulation body
in accordance with the invention with a thermoelectric element.
[0065] FIG. 1 shows a vacuum insulation body 1 whose vacuum zone is
defined, i.e. bound, by a vacuum-tight envelope 2. The envelope is
preferably a high barrier film.
[0066] In addition, a thermoelectric element 3 can be recognized
having semiconductor pellets which connect the two thermoconductive
bodies 4 or extend between them in the drawing. The thermoelectric
element 3 has two surfaces 31, 32, between which a temperature drop
can be adopted, in a direction extending transversely to the
alignment of the semiconductor pellets. To transport the
temperature present at these surfaces 31, 32 efficiently to
marginal regions of the envelope 2, the respective thermoconductive
bodies 4 are connected both to the envelope 2 and to the surface
31, 32 of the thermoelectric element 3.
[0067] The thermoconductive bodies 4 have a cross-sectional area
which increases in size toward the margin of the vacuum insulation
body starting from the thermoelectric element 3.
[0068] In addition, a heat exchanger 5 can be recognized which is
arranged outside the vacuum zone and which is configured to take up
or emit the heat transported through the respective
thermoconductive bodies 4.
[0069] The thermoconductive bodies 4 and the heat exchanger 5, i.e.
the primary 4 and the secondary heat exchanger 5, are
thermoconductively connected to one another. The heat conduction
takes place through the thin film. Provision can be made, as shown
in the drawing, that the thickness of the films 2 is reduced with
respect to the other regions at the inside and outside in the
region of the heat exchanger 4 to ensure a better heat exchange.
Alternatively, the thickness of the film 2 can, however, also be
unchanged in this region, which is advantageous in production and
increases the vacuum-tightness of the system.
[0070] Vacuum is present within the vacuum insulation body so that
the thermoelectric element 3 and the primary heat exchangers 4 are
located completely within the evacuated zone.
[0071] A support core, for example in the form of a powder, and
preferably in the form of Pearlite powder, is furthermore present
within the evacuated region between the films. If this powder is
also present between the semiconductor pellets of the Peltier
element, both the gas thermal conduction and the radiation heat
exchange between the hot and cold sides of the Peltier element or
of the thermoelectric element are thereby suppressed.
* * * * *