U.S. patent application number 15/318986 was filed with the patent office on 2017-05-04 for cooling and/or freezing device.
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 | 20170122650 15/318986 |
Document ID | / |
Family ID | 54706799 |
Filed Date | 2017-05-04 |
United States Patent
Application |
20170122650 |
Kind Code |
A1 |
Hiemeyer; Jochen ; et
al. |
May 4, 2017 |
Cooling And/Or Freezing Device
Abstract
The present invention relates to a cooling and/or a freezing
device comprising a cooled inner chamber (100) and a thermoelectric
element (20), particularly a Peltier element (20), which is
arranged such that the inner chamber (100) is cooled by means of
the thermoelectric element (20), means (4, 20, 40) for evaporating
the condensed water being provided comprising a heat exchanger (40)
located outside of the cooled inner chamber (100).
Inventors: |
Hiemeyer; Jochen;
(Karlstadt, DE) ; Kerstner; Martin; (Wurzburg,
DE) ; Freitag; Michael; (Wurzburg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LIEBHERR-HAUSGERATE LIENZ GMBH
LIEBHERR-HAUSGERATE OCHSENHAUSEN GMBH |
Lienz
Ochsenhausen |
|
AT
DE |
|
|
Family ID: |
54706799 |
Appl. No.: |
15/318986 |
Filed: |
June 16, 2015 |
PCT Filed: |
June 16, 2015 |
PCT NO: |
PCT/EP2015/001213 |
371 Date: |
December 15, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25D 29/00 20130101;
F25B 21/02 20130101; F25D 2321/141 20130101; F25B 2321/025
20130101; F25B 2321/023 20130101; F25D 2700/02 20130101; F25B
2321/021 20130101; F25D 21/14 20130101; F25D 2321/147 20130101 |
International
Class: |
F25D 21/14 20060101
F25D021/14; F25D 29/00 20060101 F25D029/00; F25B 21/02 20060101
F25B021/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 16, 2014 |
DE |
10 2014 008 668.2 |
Jan 29, 2015 |
DE |
10 2015 001 060.3 |
Feb 2, 2015 |
DE |
10 2015 001 281.9 |
Feb 3, 2015 |
DE |
10 2015 001 368.8 |
May 20, 2015 |
DE |
10 2015 006 560.2 |
Claims
1. A refrigerator unit and/or a freezer unit having a refrigerated
inner space and having a thermoelectric element, in particular
having a Peltier element, that is arranged such that the inner
space is refrigerated by means of the thermoelectric element,
characterized in that means for evaporating condensed water are
present that have a heat exchanger located outside the refrigerated
inner space.
2. A refrigerator unit and/or a freezer unit in accordance with
claim 1, characterized in that the heat exchanger is formed by the
hot side of a thermoelectric element or is connected to the hot
side of a thermoelectric element.
3. A refrigerator unit and/or a freezer unit in accordance with
claim 2, characterized in that the thermoelectric element is
arranged such that it cools the inner space of the unit by its cold
side or by a heat exchanger connected to the cold side.
4. A refrigerator unit and/or a freezer unit in accordance with
claim 1, characterized in that means are provided by which it can
be determined whether condensed water is present; and in that a
control or regulation unit connected to these means is provided
that increases the performance of the means for evaporating
condensed water when the presence of condensed water is
determined.
5. A refrigerator unit and/or a freezer unit in accordance with
claim 1, characterized in that a condensate surface is present in
the refrigerated inner space whose temperature is below the
temperature of other surfaces in the refrigerated inner space so
that condensate is formed at the condensate surface, with provision
preferably being made that the condensate surface is formed by a
thermoelectric element; and/or in that a control or regulation unit
is provided by which the condensate surface is cyclically
cooled.
6. A refrigerator unit and/or a freezer unit in accordance with
claim 5, characterized in that a detection means for detecting the
opening of the closing element of the unit is present; and in that
the control or regulation unit is configured such that it carries
out the cyclic cooling in dependence on the detected opening.
7. A refrigerator unit and/or a freezer unit in accordance with
claim 1, characterized in that a fan is present that is arranged
such that it circulates the air located in the refrigerated inner
space.
8. A refrigerator unit and/or a freezer unit in accordance with
claim 5, characterized in that the condensate surface is formed by
a thermoelectric element that is arranged such that it emits the
waste heat into the refrigerated inner space.
9. A refrigerator unit and/or a freezer unit in accordance with
claim 1, characterized in that an outflow element is provided
through which condensed water is transported to the means for
evaporation.
10. A refrigerator unit and/or a freezer unit in accordance with
claim 9, characterized in that the outflow element is dimensioned
such that the transport of the condensed water takes place by
capillary forces.
11. A refrigerator unit and/or a freezer unit having a refrigerated
inner space and having a thermoelectric element introduced thereto,
characterized in that a control or regulation unit is provided
which controls the thermoelectric element such that it forms a
condensate surface.
Description
[0001] The present invention relates to a refrigerator unit and/or
a freezer unit having at least one refrigerated inner space and
having at least one thermoelectric element, in particular having at
least one Peltier element that is arranged such that the inner
space can be cooled by the thermoelectric element.
[0002] Hot air enters into the refrigerated inner space on the
opening of refrigerator units and/or freezer units. The saturation
vapor pressure drops due to the cooling of the air, which has the
result that moisture from the air condenses at the cold surfaces of
the refrigerated inner space.
[0003] In refrigerator units and/or freezer units known from the
prior art, the condensed water is collected due to the
configuration of the refrigeration system and is led to the outside
by a drainage channel or the like. It is collected in a
condensation tray there which can be located above the compressor.
The water in the condensation tray evaporates due to the waste heat
of the compressor.
[0004] For efficiency reasons, it is constructive in a
thermoelectric refrigerator unit or freezer unit to keep the
temperature difference at the heat pump much smaller than in a
compression refrigeration machine. This has the result that no
considerably colder surface is present in the refrigerated inner
space at which the condensation takes place and that no location
having a locally elevated temperature is present at the unit
exterior which could be used for evaporating the condensation.
[0005] It is the underlying object of the present invention to
further develop a refrigerator unit and/or a freezer unit of the
initially named kind such that a reliable evaporation of the
condensed water led out of the refrigerated inner space takes
place.
[0006] This object is achieved by a refrigerator unit and/or
freezer unit having the features of claim 1. Means are accordingly
present for evaporating condensed water that have a heat exchanger
located outside the refrigerated inner space. The term "heat
exchanger" is to be understood as any element that has a
temperature that is sufficient for evaporating condensed water.
[0007] Provision is made in an embodiment of the invention that the
heat exchanger is formed by the hot side of a thermoelectric
element or by an element such as a metal body that is connected in
a heat-transferring manner, in particular a thermoconductive
manner, to the hot side of a thermoelectric element. This
thermoelectric element can simultaneously be arranged such that its
cold side refrigerates the inner space of the unit.
[0008] Such an arrangement can be operated in a stationary manner
by means of a control or regulation unit, i.e. the thermoelectric
element is operated at a constant capacity or at a capacity that is
required for maintaining the temperature in the refrigerated inner
space as constant and at least independently of the condensed water
that results.
[0009] In a conceivable case, there is an apparatus for this
purpose at a surface in the refrigerated inner space of the unit at
which the lowest temperature is present due to the positioning of
the thermoelectric cooling for the collecting and leading off of
the condensed water. The latter is led out of the unit and moves
into a collection tray that is arranged, for example, around a
region of the outer skin at which an elevated temperature is
present.
[0010] This procedure can be sufficient for moderate climate
conditions.
[0011] For conditions or regions having particularly high humidity,
the incurred moisture quantity can be so large that, on the one
hand, the condensation no longer takes place locally at the coldest
point due to the small temperature spread, i.e. the small
temperature gradient, in the inner space. It is a further problem
that the temperature at the evaporation region is not high enough
to evaporate the total condensed water.
[0012] To counter this, provision is made in a further embodiment
of the invention that a control or regulation unit is present for
carrying out one or more condensation cycles. This unit is
configured such that it increases the temperature spread for the
purpose of condensation and/or evaporation during a condensation
cycle.
[0013] This means that the capacity, e.g. of a thermoelectric
element, is increased during the condensation cycle such that its
temperature is lowered in the refrigerated inner space with respect
to normal operation in which no condensation cycle is present
and/or such that its temperature of the thermoelectric element at
the outside of the unit is increased with respect to normal
operation in which no condensation cycle is present.
[0014] The condensation cycle can be carried out at specific,
optionally regular, time intervals or can depend on one or more
parameters. Such a parameter is, for example, the humidity and/or
the quantity of formed condensed water. These parameters can be
supplied to the control or regulation unit that then initiates a
condensation cycle in dependence thereon or continues to operate
the unit in normal operation.
[0015] It is conceivable that means are provided by which it can be
determined whether condensed water is present and that the control
or regulation unit connected with these means can be configured
such that the performance of the means for evaporating condensed
water is increased and/or that the temperature is lowered at at
least one point in the refrigerated inner space when the presence
of condensed water is found.
[0016] To concentrate the condensate at one point or at a plurality
of points, provision can be made that at least one condensate
surface is present in the refrigerated inner scape whose
temperature is below that of other surfaces in the refrigerated
inner space so that condensate is formed at the condensate
surface.
[0017] The condensate surface can be formed by at least one
thermoelectric element. It can in this respect be a thermoelectric
element that is anyway used for refrigerating the refrigerated
inner space or also a thermoelectric element especially used for
the condensate formation.
[0018] The thermoelectric element used especially for the
condensate formation can be arranged such that it emits its waste
heat to the refrigerated inner space. The element can thus work
very efficiently and can be operated at minimal capacity. The cold
generation and the condensate formation are effectively decoupled
by this additional thermoelectric element so that the framework
conditions of cold generation do not have to be considered in the
design of the condensation geometry.
[0019] It is conceivable that a detection means is present for
detecting the opening of the closing element of the unit and that
the control or regulation unit is designed for cyclic cooling such
that it is operated in dependence on the detected opening. An
embodiment of the invention can thus comprise always initiating the
condensation cycle after a door opening, i.e. when the door or
another closing element is closed again, guiding the hot air newly
moved in over the condensation point.
[0020] To support the deposition of humidity at the condensation
surface, it can be meaningful for a fan to be present that is
arranged such that it circulates the air located in the
refrigerated inner space.
[0021] Alternatively or additionally, at least one fan can be
provided in the evaporation region to promote the evaporation
rate.
[0022] At least one outflow element can be provided by which
condensed water is transported to the means for evaporation, with
provision preferably being made that the outflow element is
dimensioned such that the transport of the condensed water takes
place by capillary forces.
[0023] In the simplest case, the outflow element is arranged such
that the condensed water simply flows out of the refrigerated inner
space due to gravity.
[0024] If the evaporation is to be aimed for at other points such
as at the top of the unit, provision can be made to conduct the
condensed water that arises via capillary forces to a specific
evaporation point or evaporation region such as the unit top.
[0025] With the refrigerator unit and/or freezer unit in accordance
with the invention, a full vacuum insulation is preferably located
between the outer skin, i.e. the outside of the carcass and the
inner wall bounding the refrigerated inner space, and/or between
the inside and outside of the door or of another closing element.
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 another closing element.
[0026] In a preferred embodiment of the refrigerator unit and/or
freezer unit in accordance with the invention, it is partly or
completely insulated using 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 that have said film,
the region surrounded by the film and the core material located
therein. 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.
[0027] 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.
[0028] 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 gas-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.
[0029] The envelope preferably comprises a high barrier film or is
a high barrier film which terminates the vacuum one formed by the
envelope in a vacuum-tight manner.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] The above-named values or the make-up of the high barrier
film are exemplary, preferred values which do not restrict the
invention.
[0034] The idea of introducing a thermoelectric element into the
refrigerated inner space in order to form a condensate surface in
this manner is not restricted to thermoelectric units. The
invention thus furthermore relates to any desired refrigerator unit
and/or freezer unit having a refrigerated inner space and having a
thermoelectric element introduced thereto, wherein a control or
regulation unit is provided which controls the thermoelectric
element such that it forms a condensate surface. The condensate
surface is preferably colder than adjacent surfaces or the coldest
surface in the refrigerated inner space.
[0035] Provision is made in an embodiment that the refrigerator
unit and/or freezer unit in accordance with the invention is a
domestic appliance or a commercial refrigeration unit. 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.
[0036] 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 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.
[0037] 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.
[0038] 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.
[0039] 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. 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.
[0040] Further details and advantages of the invention will be
described in more detail with reference to the embodiment shown in
the Figures and described in the following. There are shown in the
Figures:
[0041] FIG. 1: a longitudinal sectional view through a refrigerator
unit and/or a freezer unit in accordance with the invention;
and
[0042] FIG. 2: a detailed view of the region of a thermoelectric
element whose hot side promotes the evaporation of condensed
water.
[0043] In FIG. 1, the carcass of a cabinet-like refrigerator unit
and/or freezer unit is marked by the reference numeral 10.
[0044] The carcass 10 has two side walls 12, a top 14 and a bottom
16. They bound the cooled inner space 100 together with the rear
wall and a door.
[0045] As can be seen from FIG. 1, a respective thermoelectric
element 20, 20' is provided in the two side walls 1, in the top
wall 14, and in the bottom 16.
[0046] Exactly one such thermoelectric element can generally be
provided per wall. However, the case is also covered by the
invention that two or more than two thermoelectric elements are
present in one or more walls.
[0047] The arrangement of one or more thermoelectric elements at
the rear side of the unit is also conceivable and covered by the
invention.
[0048] Each of the thermoelectric elements 20 is connected in a
heat-transferring manner, in particular in a thermoconductive
manner, to a respective one heat exchanger 30, 40 both on the cold
side facing the inner space 100 and on the outwardly directed hot
side. These primary heat exchangers 30, 40 are metal bodies, e.g.
composed of aluminum.
[0049] In the operation of the thermoelectric elements 20, heat is
extracted from the cooled inner space over their cold sides and by
means of the heat exchanger 30 and of the inner wall I. This heat
is discharged to the environment via the hot side of the
thermoelectric element 20, via the heat exchanger 40 and via the
outer wall A.
[0050] As can further be seen from FIG. 1, the cross-section of the
primary heat exchangers 1, 40 increases, starting from the
thermoelectric element 20 toward the outer wall A and also toward
the inner wall I which bounds the cooled inner space 100 together
with the inside of the door. In this manner, the waste heat which
is extracted from the inner space 100 by means of the
thermoelectric elements 20 can be distributed over a larger surface
without a larger temperature gradient.
[0051] The outer unit side is formed by the outer wall A which
comprises in total or regionally a metal sheet, preferably an
aluminum metal sheet.
[0052] In the embodiment shown here, this metal sheet forms the
outer side A of the side walls 12, of the top 14 and also of the
bottom 16. The rear side and/or the door can also be
correspondingly formed on the outer side.
[0053] The metal sheet forming the outer wall A forms the secondary
heat exchanger which is connected in a heat-transferring manner, in
particular in a thermoconductive manner, to the primary heat
exchangers 40.
[0054] The inner wall I is likewise formed by a metal sheet, in
particular by an aluminum metal sheet. The inner wall I is
connected in a heat-transferring manner, in particular in a
thermoconductive manner, to the primary heat exchangers 30.
[0055] The term "heat exchanger" in accordance with the present
invention includes any desired element that is suitable for
transferring heat. In the preferred embodiment, the heat exchangers
are formed by metallic bodies.
[0056] Reference numeral 50 denotes the heat insulation which
extends between the inner wall I and the outer wall A of the
carcass. This thermal insulation comprises a volume which is
bounded by one or more vacuum-tight films and in which a core
material, in particular pearlite, is located. Further insulating
materials such as foaming and/or vacuum insulation panels are
preferably provided between the inner wall I and the outer wall
A.
[0057] A corresponding full vacuum thermal insulation can also be
provided for the door or for another closing element.
[0058] The Peltier elements 20 or the other thermoelectric elements
are distributed over the unit geometry such that their waste heat
is distributed as much as possible over the outer skin A of the
unit. The outer skin A can be made up of an aluminum metal sheet
having a thickness of 1 to 2 mm for the distribution of the waste
heat over the complete outer skin A.
[0059] Since the cooling energy which is generated is smaller than
the waste heat, the demands on the heat exchanger are not so high
in the unit interior 100. A metal sheet (e.g. an aluminum metal
sheet) is preferably equally used for the inner wall of the unit
and can have a smaller thickness than the metal sheet forming the
outer skin A or can have an identical configuration.
[0060] The cold side of the thermoelectric element 20' arranged at
the bottom is connected to the heat exchanger 30 that forms a
condensation surface at its upper side O, i.e. a surface that has a
smaller temperature with respect to adjacent surfaces or that
represents the lowest temperature in the refrigerated inner
space.
[0061] A detailed view of the region of the thermoelectric element
20' arranged at the bottom is shown in FIG. 2. A condensation
region 1 is formed around and at the condensation surface of the
heat exchanger 30. Starting from this condensation region 1 at the
inner side of the thermally insulating unit wall, an outflow 2 for
the condensate leads to the evaporation region 200.
[0062] The evaporation region 200 is formed by an evaporation tray
4 that collects the condensed water and that is in good thermal
coupling to the Peltier element 20'. The evaporation tray 4 is in
particular in direct or thermally conductive contact with the heat
exchanger 40.
[0063] As can furthermore be seen from FIG. 2, the Peltier element
20' can have, in the same way as the other Peltier elements of the
unit in accordance with the invention, connection elements 33 that
mechanically fixedly clamp the Peltier element 20' to the heat
exchangers 30 and 40.
[0064] The thermoelectric element or the Peltier element 20'
arranged in the base surface is controllable separately by a
control or regulation unit, not shown, and indeed such hat its
performance is increased within the framework of a condensation
cycle or as required. This has the result that the upper cold side
O adopts a still lower temperature and the lower hot side W adopts
an even higher temperature.
[0065] The condensation and the evaporation are improved in this
manner.
[0066] In normal operation, the thermoelectric element 20', like
the further thermoelectric elements, can be used in dependence on
the measured inner space temperature, i.e. for temperature
regulation.
[0067] It is also conceivable to use an additional thermoelectric
element that lies, for example, on the base surface of the unit and
forms the coldest point there. This thermoelectric element thus
does not extend between the outside and inside of the unit, but is
rather completely located in the refrigerated inner space and emits
its waste heat therein.
* * * * *