DE102019210190B4 - THERMOELECTRIC COOLING UNIT - Google Patents

Abstract

Thermoelectric cooling unit (1) for a refrigerator (100) comprising a Peltier element (9) having a cold side (9a) and a hot side (9b) during operation, the cold side (9a) of the Peltier element (9) for Heat exchange with the interior of the refrigerator (100) and the hot side (9b) of the Peltier element (9) is intended for heat exchange with the environment, the thermoelectric cooling unit (1) further comprises a heat sink (8) which is thermally connected to the cold side ( 9a) of the Peltier element (9) to increase heat exchange with the interior of the refrigerator (100), the thermoelectric cooling unit (1) further comprising a boiler (2) and a heat pipe (7) thermally connected to the hot Side (9b) of the Peltier element (9) are coupled to increase the heat exchange with the environment, the boiler (2) being connected to the hot side (9b) of the Peltier element (9), the boiler (2) having an outlet connection ( 4) and a return connection (5 ) and the heat pipe (7) connects the outlet port (4) to the return port (5), thus forming a closed circuit, the boiler (2) having a first side wall (2c), at least a part of which is covered with the Peltier element (9) is in contact and the boiler (2) is designed in such a way that when assembled and filled with a liquid refrigerant, the liquid refrigerant inside the boiler (2) covers the entire part of the first side wall (2c) that is connected to the Peltier element (9) is in contact and the boiler (2) is designed in such a way that the boiler (2) can only be partially filled with the liquid refrigerant, characterized in that the boiler (2) is cuboid and in the assembled state both the Peltier element ( 9) as well as the first side wall (2c) are mainly flat and arranged in a plane inclined by 1° to 3° from a vertical plane, so that the Peltier element (9) and the first side wall (2c) face the refrigerator (10th 0) are tilted.

Description

The present invention relates to a thermoelectric cooling unit for a refrigerator such as a minibar, and a refrigerator having such a thermoelectric cooling unit.

Refrigerators are usually equipped with a compressor-type refrigeration unit. In it, a refrigerant circuit runs from the inside of the refrigerator to the outside and back again, thus dissipating the heat energy from the inside of the refrigerator to the outside. The respective operating principle is well known and the compressor type refrigeration unit has several disadvantages. Because the refrigerant circuit also passes through the inside of the refrigerator, where it evaporates, damage to the evaporator can occur, especially when the evaporator is defrosted, and refrigerant can leak inside the refrigerator. In addition, the compressor makes noise that can be annoying, especially in hotel rooms equipped with a minibar-style refrigerator.

Another type of cooling is based on the thermoelectric effect, more precisely the Peltier effect. The Peltier effect is based on the contact of two semiconductors that have different energy levels (either p-type or n-type) of the conduction bands. If a current is passed through two consecutive contact points of these materials, thermal energy must be absorbed at one contact point so that the electron can reach the energetically higher conduction band of the neighboring semiconductor material, which leads to cooling. At the other contact point, the electron falls from a higher to a lower energy level, so that energy is released here in the form of heat.

Since n-doped semiconductors have a lower energy level of the conduction band, cooling takes place at the point where electrons pass from the n-doped to the p-doped semiconductor (technical current flow from the p-doped to the n-doped semiconductor).

A Peltier element essentially consists of two or more small blocks of p- and n-doped semiconductor material, e.g. bismuth telluride and silicon germanium, which are mutually connected at the top and bottom by metal bridges. The metal bridges also form the thermal contact surfaces and are electrically insulated by an overlying foil or ceramic plate. Two different cuboids are always connected with each other in such a way that they form a series connection. The electrical current supplied flows through all the cuboids one after the other. Depending on the magnitude and direction of the current, the top connections cool down while the bottom ones heat up. So the current pumps heat from one side to the other, creating a temperature difference between the plates.

A common form of Peltier elements consists of two mostly square plates made of aluminum oxide ceramic with an edge length of 20 mm to 90 mm and a distance of 3 mm to 5 mm between which the semiconductor blocks are soldered. For this purpose, the ceramic surfaces are provided with solderable metal surfaces on their top surfaces.

If the hot side is cooled, e.g. by a heat sink with a fan, the cold side becomes even colder. Depending on the element and the current, the temperature difference between the two sides can be up to approx. 70 Kelvin.

A corresponding thermoelectric cooling unit for a refrigerator is for example in U.S. 2019/203983 A1 described. However, cooling the hot side with a fan again involves a motorized component that generates noise. In addition, the ventilation can collect dirt and dust, which is also undesirable.

The present invention addresses this issue and aims to provide a refrigeration unit for refrigerators, such as a minibar, without the disadvantages mentioned above.

In order to achieve the object, the present invention provides a thermoelectric cooling unit for a refrigerator with a Peltier element, which has a cold side and a hot side during operation. The cold side of the Peltier element is intended for heat exchange with the inside of the refrigerator. The hot side of the Peltier element is intended for heat exchange with the environment. The thermoelectric cooling unit further includes a heat sink thermally coupled to the cold side of the Peltier element to increase heat exchange with the interior of the refrigerator.

According to the invention, the thermoelectric cooling unit also has a boiler and a heat pipe. The boiler and the heat pipe are thermally coupled to the hot side of the Peltier element to increase the heat exchange with the surroundings, the boiler being connected to the hot side of the Peltier element. The boiler has an outlet connection and a return connection. The heat pipe connects the outlet port to the return port, forming a closed loop.

Thermoelectric cooling units for refrigerators according to the preceding preamble of the present invention are, for example, from U.S. 2019/203983 A1 , from the CN 2520484 Y and from the KR 101889256 B1 known.

According to the invention, the boiler has a first side wall, at least part of which is in contact with the Peltier element, and the boiler is designed such that when assembled and filled with a liquid refrigerant, the liquid refrigerant inside the boiler covers the entire part of the first side wall covered, which is in contact with the Peltier element. In this context, the term "filled" is not intended to say anything about the degree of filling. When the liquid refrigerant covers the inner surface of the first side wall at least in the area where the opposite outer surface of the first side wall is in contact with the hot side of the Peltier element, the cooling efficiency of the hot side of the Peltier element is increased. The terms "inside" and "outside" refer to the inside and outside of the boiler.

According to the invention, the boiler is also designed in such a way that the boiler can only be partially filled with the liquid refrigerant. This ensures that there is a gas layer above the liquid level inside the boiler, which prevents the liquid from being forced into the heat pipe during boiling.

According to the invention, the boiler is cuboid and when assembled, both the Peltier element and the first side wall are predominantly flat and arranged in a plane inclined by 1° to 3° from a vertical plane, so that the Peltier element and the first side wall are tilted up towards the refrigerator are. In this configuration, the area of the first side wall that is in contact with the hot side of the Peltier element is completely covered by the liquid refrigerant and the boiling refrigerant and vapor bubbles can escape up and along the sloping top of the boiler away from the first side wall into the vapor zone above the liquid level where the outlet port is located. This configuration ensures efficient convection of the liquid refrigerant in the boiler.

The central aspect of the present invention thus relates to the cooling of the hot side of the Peltier element using the heat pipe principle, which is known as such for the provision of highly effective heat conductors.

The working principle of the present invention is that a liquid refrigerant starts to boil inside the boiler due to thermal energy provided by the hot side of the Peltier element. The refrigerant vaporizes and the evaporate or vapor passes through the heat pipe, condenses back into liquid within the heat pipe, releasing the thermal energy to the surroundings, and flows back into the boiler.

Thus, together with the heat pipe, the boiler represents a form of heat sink coupled to the hot side of the Peltier element.

However, as already mentioned, the heat sink on the cold side of the Peltier element works in reverse. According to the strict sense of the term "heat sink", the "heat sink" as used in the context of the present invention represents a heat sink for the interior of the refrigerator, which transfers the heat from there to the cold side of the Peltier element.

Also within the scope of the present invention, the term “during operation” designates a situation in which the refrigerator is operated as intended.

Furthermore, whenever an “assembled state” of the thermoelectric cooling unit is mentioned, a state is meant in which the thermoelectric cooling unit is fully assembled on the refrigerator and the refrigerator is ready for operation.

In addition to any type of refrigerator or minibar, the term “refrigerator” also includes a freezer within the scope of the present invention.

For example, terms relating to an orientation of a component, such as "top", "bottom", "up", "down", "vertical", "horizontal", and similar terms refer to the surface of the earth, unless unless another specific reference is expressly made in the respective context.

In a preferred embodiment of the thermoelectric cooling unit according to the present invention, the heat pipe is a single continuous pipe without branches. This leads to fewer components and thus lower production and assembly costs. In addition, high efficiency can be guaranteed as unpredictable effects on steam convection are eliminated in two or more parallel tubes.

According to a preferred aspect of the present invention, the heat pipe is provided with a plurality of wires on its outside. This increases the effectiveness of the condensation and cooling of the refrigerant within the heat pipe.

According to a further preferred aspect of the present invention, the outlet connection is arranged on an upper side of the boiler in the assembled state and the heat pipe leads away from the outlet connection and upwards. Gravity is used here, as hot steam rises and this promotes the flow of steam in the circuit.

According to a further preferred aspect of the present invention, the heat pipe extends at least partially in a serpentine form. As a result, a long heat pipe with a small space requirement can be implemented.

According to a further preferred aspect of the present invention, the return connection is arranged on an underside of the boiler in the mounted state and the heat pipe leads away from the return connection and downwards. Gravity is used here, since condensed and cold liquid with the highest density enters the boiler from below and the refrigerant flow is thus promoted in the circuit.

According to a further preferred aspect of the present invention, the heat pipe extends predominantly within one plane or within at least two parallel planes. In particular, the serpentine section of the heat pipe is predominantly provided within the plane(s). This arrangement saves space.

According to a further, even more preferred aspect of the present invention, the one plane or the at least two parallel planes in which the heat pipe predominantly extends are arranged vertically in the assembled state. This makes the entire refrigerator compact.

According to a further preferred aspect of the present invention, the heat sink is plate-shaped at least in sections and is in contact with the Peltier element on one side of the plate shape. This achieves a high surface area of the heat sink, which increases the heat conduction from the inside of the refrigerator to the cold side of the Peltier element. The material of the heatsink is not particularly limited, and may be made of a metal having high thermal conductivity as in known heat sinks.

According to a further preferred aspect of the present invention, the thermoelectric cooling unit further comprises fastening means for fastening the boiler to the heat sink, whereby the Peltier element is clamped between the boiler and the heat sink. This provides a simple and stable arrangement and ensures efficient transfer of thermal energy from the heat sink to the heat pipe.

According to a further preferred aspect of the present invention, there are at least four fixing means arranged around the Peltier element in a plan view of the plate-shaped portion which is in contact with the Peltier element. This is particularly advantageous with square Peltier elements. There is a fastener near each corner of the Peltier element. Due to the temperature difference between the hot and cold sides of the Peltier element, the entire device bends so that the cold side becomes concave and the hot side convex. The four fasteners at the corners of the Peltier elements push the Peltier element back to planarity, ensuring contact and heat transfer over the entire surface of the Peltier element.

According to a further preferred aspect of the present invention, the fastening means are hooks which protrude from the side of the boiler through holes in the heat sink and hook onto the other side of the heat sink. This enables easy assembly and a reliable connection.

According to another preferred aspect of the present invention, the thermoelectric cooling unit further includes an accommodating portion for accommodating the Peltier element and preventing the Peltier element from moving along the surface of the plate shape of the heat sink that is in contact with the Peltier element. In principle, the recording area consists of wall elements that enclose the Peltier element on the side. This increases the stability of the arrangement. The receiving area or the wall elements preferably have suitable recesses or grooves in order to ensure a cable connection to the Peltier element.

According to a further preferred aspect of the present invention, the fastening means and the receiving area are integrated in the boiler, which is mainly made of a plastic material. As such, the boiler is a one-piece component and no additional fasteners, such as screws or brackets, are required to mount to the heatsink and attach and accommodate the Peltier element between the heat sink and the boiler. This reduces the assembly work and the manufacturing costs.

According to a further preferred aspect of the present invention, the boiler has an aluminum plate as the first side wall, so that in operation only the aluminum plate is between the hot side of the Peltier element and the refrigerant. Thus, the one-piece plastic component for the boiler is open on the side where the Peltier element is to be located. In this area, the aluminum plate is present instead. The aluminum plate ensures more efficient and effective cooling of the hot side of the Peltier element. The term "aluminum plate" is not intended to limit the material of the aluminum plate to pure aluminum. Rather, those skilled in the art will appreciate that a variety of suitable materials can be selected for this purpose, most of which are likely to contain high levels of aluminum, which is the reason for the naming of the particular panel as an aluminum panel. Therefore, any material that is suitable for use as aluminum plate is summarized under the term "aluminum plate".

According to a further preferred aspect of the present invention, the aluminum plate is already integrated into the boiler during the plastic molding process. This ensures a reliable and tight connection between the one-piece plastic boiler and the aluminum plate. For example, in gas injection molding, the aluminum plate can already be used in the mold.

According to a further preferred aspect of the present invention, the boiler is held by a housing in which the fastening means and the receiving area are integrated. The housing preferably consists of wall elements which at least partially enclose the boiler on all sides. "At least partially" here means that the wall parts may have free areas where the boiler is exposed, e.g. at the outlet connection, at the return connection and at a connection for a service line. In the case of a cuboid boiler, the wall elements forming the housing are preferably present on all six sides. The separation of the boiler function and the fixing function achieved by the housing has several advantages. On the one hand, the boiler is exposed to less mechanical stress. The boiler can be made from another material, such as a simple parallelepiped of steel plates. The case can be designed solely with the mounting purposes in mind, leading to more effective and efficient results.

According to a further preferred aspect of the present invention, the receiving area on the housing is represented by an open area into which the Peltier element fits. In a preferred embodiment, the first side wall is covered by a wall element of the housing only in the area of its edges. In the central area of the first side wall, however, the boiler is exposed through the open area. This reliably holds the Peltier element in place while at the same time enclosing the boiler.

According to a further preferred aspect of the present invention, the housing has a material thickness in the area of the open area which is smaller than the thickness of the Peltier element. That is, the wall element of the housing covering the edges of the first side wall is thinner than the Peltier element. This ensures direct contact between the heat sink and the Peltier element on the one hand and the Peltier element and the first side wall of the boiler on the other hand.

According to a further preferred aspect of the present invention, the housing has pressing means located in the vicinity of a second side wall of the boiler, opposite to the first side wall. The second side wall of the boiler and the respective wall element of the housing are pushed apart by the pressing means and, since the housing is fastened to the heat sink by the fastening means, the boiler as a whole is pushed and pressed against the Peltier element and the Peltier element is pushed against the heat sink and pressed against them. This represents a simple and highly effective configuration in terms of stability and heat transfer.

According to a further preferred aspect of the present invention, the pressing means comprises a screw or bolt which passes through the housing and acts on the middle of the second side wall of the boiler to press the boiler with its first side wall against the Peltier element. This allows the boiler to be easily pushed to the Peltier element from outside the housing by simply screwing in the screw or bolt. Preferably the screw can be passed through a threaded hole in the housing so that the tip of the screw exerts a corresponding force on the second side wall of the boiler.

According to a further aspect of the present invention, a refrigerator is provided with a thermoelectric cooling unit according to the present invention, wherein during operation the cold side of the Peltier element is connected to the interior of the refrigerator via the heat sink and the hot side of the Peltier element is in heat exchange with the surroundings via the boiler and the heat pipe, and wherein the boiler is only partially filled with a liquid refrigerant and the liquid refrigerant inside the boiler covers the entire part of the first side wall that is connected to the Peltier element is in contact. Advantageous effects of this solution have already been described above.

• 1 eine Seitenansicht einer Ausführungsform der thermoelektrischen Kühleinheit;
• 2 eine vergrößerte perspektivische Ansicht der thermoelektrischen Kühleinheit von 1;
• 3 einen vertikalen und längsseitigen Querschnitt durch die thermoelektrische Kühleinheit von 1;
• 4 einen vertikalen und längsseitigen Querschnitt durch einen Kühlschrank, der mit der thermoelektrischen Kühleinheit von 1 ausgestattet ist;
• 5 eine perspektivische Ansicht der thermoelektrischen Kühleinheit von 1 ohne die Drähte;
• 6 eine perspektivische Ansicht des Boilers und des Peltierelements der thermoelektrischen Kühleinheit von 1;
• 7 eine Explosionsdarstellung des Boilers und des Peltierelements der thermoelektrischen Kühleinheit von 1;
• 8 eine weitere perspektivische Ansicht des Boilers der thermoelektrischen Kühleinheit von 1;
• 9 eine Explosionsdarstellung der thermoelektrischen Kühleinheit von 1;
• 10 eine perspektivische Ansicht einer weiteren Ausführungsform des Boilers der thermoelektrischen Kühleinheit;
• 11 den Boiler von 10 in einer weiteren perspektivischen Ansicht;
• 12: eine perspektivische Ansicht in den Boiler von 10; und
• 13 eine Ausführungsform der Wärmesenke zeigt.

In the following, embodiments of the present invention are described in more detail with reference to the attached drawings, wherein

• 1 a side view of an embodiment of the thermoelectric cooling unit;
• 2 12 is an enlarged perspective view of the thermoelectric cooling unit of FIG 1 ;
• 3 Fig. 14 shows a vertical and longitudinal cross-section through the thermoelectric cooling unit of fig 1 ;
• 4 a vertical and longitudinal cross-section through a refrigerator with the thermoelectric cooling unit of 1 Is provided;
• 5 FIG. 12 is a perspective view of the thermoelectric cooling unit of FIG 1 without the wires;
• 6 FIG. 14 is a perspective view of the boiler and the Peltier element of the thermoelectric cooling unit of FIG 1 ;
• 7 an exploded view of the boiler and the Peltier element of the thermoelectric cooling unit of 1 ;
• 8th 12 is another perspective view of the boiler of the thermoelectric cooling unit of FIG 1 ;
• 9 an exploded view of the thermoelectric cooling unit of 1 ;
• 10 a perspective view of another embodiment of the boiler of the thermoelectric cooling unit;
• 11 the boiler from 10 in another perspective view;
• 12 : a perspective view inside the boiler of 10 ; and
• 13 shows an embodiment of the heat sink.

A first embodiment of the present invention will be described with reference to FIG 1 until 9 described. As in the 1 until 4 shown, the thermoelectric cooling unit 1 consists of the heat sink 8, the Peltier element 9, the boiler 2 and the heat pipe 7.

The heat sink 8 is intended to be located in the refrigerator 100 or in the minibar and consists of a metal or other material with high thermal conductivity. As in the 6 , 7 and 9 shown, the heat sink 8 is in contact with the cold side 9a of the Peltier element 9 and supplies the cold room 102 of the refrigerator 100 with cold. To this end, the heat sink 8 has a plurality of fins 11 for increased surface area promoting heat transfer efficiency.

The boiler 2 is directly coupled to the heat sink 8 and the Peltier element 9 is arranged between the boiler 2 and the heat sink 8 . In particular, the boiler 2 is surrounded by a housing 12 which in turn consists essentially of two half-shells 24 and a cover 13 . The boiler 2 is also equipped with connections, in particular the outlet connection 4 and the return connection 5 as well as the service line 6. The outlet connection 4 is located on the top 2a of the boiler 2. When using the thermoelectric cooling unit 1, the vapor of the refrigerant is discharged through the outlet line 4 and flows upwards into the heat pipe 7. The heat pipe 7 first leads steeply upwards and then, step by step, like serpentines, back down again. Wires 14 are arranged on the heat pipe 7 for more efficient heat transfer to the surroundings. At this time, the refrigerant vapor condenses inside the heat pipe 7 , flows down the heat pipe 7 , and returns to the boiler 2 via the return port 5 .

In the illustrated embodiment of the thermoelectric cooling unit 1, the boiler 2 is made of steel. Regardless of the material of the boiler 2, the boiler 2 is in close contact with the Peltier element 9 while at the same time the Peltier element 9 is in close contact with the heat sink 8. All this is achieved through the housing 12 and its fastening means 3. The two half-shells 24 and the cover 13 of the housing 12 are connected to one another via the cover hooks 15 which are present on the cover 13 and which engage in corresponding undercuts 16 on the half-shells 24 . The half-shells 24 also engage in one another via the lugs 17 and grooves 18 .

As in the in 3 As can best be seen from the cross-sectional view shown, the boiler 2 is located inside the housing 12 and is pressed onto the hot side 9b of the Peltier element 9 by the pressing means 19 . The pressing means 19 includes a screw 26 which passes through the center of the lid 13 where a threaded hole 27 is turned is needed. The opposing force of the pressing force with which the boiler 2 is pressed onto the Peltier element 9 is transmitted to the heat sink 8 via the cover 13 , the half-shells 24 and finally via the hooks 20 . As a result, the Peltier element 9 is pressed from both sides only by actuating this one screw 26 and a close contact for efficient heat transfer from the Peltier element 9 to the heat sink 8 on the one hand and from the Peltier element 9 to the boiler 2 on the other hand is ensured.

As in 1 As best seen, the curved heat pipe 7 extends in two parallel serpentine planes. The heat sink 8 also essentially lies within a plane which, however, is not parallel to the planes of the heat pipe 7 . In fact, the planes of the heat pipe 7 are inclined away from the plane of the heat sink 8 by the angle of 2°. The thermoelectric cooling unit 1 is now mounted on the refrigerator so that the planes of the heat pipe are parallel to the door 101 and the walls of the refrigerator 100 to be perpendicular to a flat floor. However, the boiler 2, the Peltier element 9 and the heat sink 8 are inclined by 2°. The advantage of this arrangement described above can be 4 be taken, where the filling level of the refrigerant is shown. Due to the inclination of 2° in this case, the liquid refrigerant covers the entire area of the first side wall 2c inside the boiler 2, which is in contact with the hot side 9b of the Peltier element. However, the space for the vapor inside the boiler 2 extends further away from the Peltier element 9 in the direction of the second side wall 2d or the outlet connection 4 and the distance from the liquid level of the refrigerant to the outlet connection increases. This effectively prevents or at least reduces the risk of delayed boiling when the refrigerant boils.

The serpentine course of the heat pipe 7 is best in 5 shown, in which the wires 14 are not shown. The heat pipe 7, starting at the outlet port 4, first runs steeply upwards and then gradually downwards horizontally. The heat pipe 4 runs alternately within the two parallel planes described above. When the heat pipe 7 almost reaches the level of the boiler 2 again, the serpentine course breaks and the heat pipe 7 runs down and up again via the return connection 5 into the boiler 2.

As in 6 can be seen, the half-shells 24 of the housing 12 have areas in which the boiler 2 is exposed, for example in the area of the connections 4 and 5 of the service line 6. In the area of the first side wall 2c, the housing has the open area 25, which is Recording area 22 for the Peltier element 9 is used.

Furthermore, in 6 the hooks 20 are identified as fasteners 3, one at each corner of the open area 25. As already mentioned, this provides that the Peltier element 9 can be pushed back into planarity should it wish to flex due to the thermal gradient during operation. Any two of the hooks 20 point in opposite directions and away from the other half-shell 24, which facilitates assembly.

As in 9 As can be seen, the hooks 20 engage in the holes 21 in the heat sink 8 . The heat sink 8 is planar and flat on the side to which the boiler is attached to ensure efficient heat transfer. On the other hand, as in 13 As can be seen, the heat sink 8 has a plurality of fins 11 in order to increase the active surface area of the heat sink 8 inside the refrigerator 100 . The fins are oriented vertically to allow condensation to drain downwards.

In the 10-12 another embodiment of the boiler 2 is shown. This boiler 2 no longer requires a housing since the fastening means 3 and the receiving area 22 for the Peltier element are integrated into the boiler 2 . In fact, the boiler 2 is made of plastic in addition to the first side wall 2c as a one-piece component. An aluminum plate 23 is used as the first side wall 2c, or more precisely cast into the boiler 2 in order to ensure efficient heat transfer.

In 12 an insight into the one-piece plastic boiler 2 is shown. The return connection 5 on the underside of the boiler 2 can be seen there. Incidentally, in this embodiment, the service line 6 or the associated connection for the service line 6 is on the same side of the boiler 2 as the outlet connection 4. Analogous to the aluminum plate 23, the pipe sections of the heat pipe emanating from the respective connections 4 and 5 can also be Insertion into the mold in the boiler 2 are formed.

Reference List

1

Thermoelectric cooling unit

2

boiler

2a

top of the boiler

2 B

bottom of the boiler

2c

First side panel

2d

Second side wall

3

fasteners

4

outlet port

5

return connection

6

service line

7

heat pipe

8th

heat sink

9

Peltier element

9a

cold side

9b

hot side

10

Peltier element cable

11

fin

12

Housing

13

cover

14

wire

15

cover hook

16

undercut

17

Nose

18

groove

19

pressing means

20

hook

21

Hole

22

recording area

23

aluminum plate

24

half shell

25

open area

26

screw

27

threaded hole

100

refrigerator

101

door

102

fridge

a

angle

Claims (22)

Thermoelectric cooling unit (1) for a refrigerator (100) comprising a Peltier element (9) having a cold side (9a) and a hot side (9b) during operation, the cold side (9a) of the Peltier element (9) for Heat exchange with the interior of the refrigerator (100) and the hot side (9b) of the Peltier element (9) is intended for heat exchange with the environment, the thermoelectric cooling unit (1) further comprises a heat sink (8) which is thermally connected to the cold side ( 9a) of the Peltier element (9) is coupled to increase heat exchange with the interior of the refrigerator (100), wherein the thermoelectric cooling unit (1) further comprises a boiler (2) and a heat pipe (7) thermally connected to the hot Side (9b) of the Peltier element (9) are coupled to increase the heat exchange with the environment, the boiler (2) being connected to the hot side (9b) of the Peltier element (9), the boiler (2) having an outlet connection ( 4) and a return connection ( 5), and the heat pipe (7) connects the outlet port (4) to the return port (5), thus forming a closed circuit, the boiler (2) having a first side wall (2c), at least part of which is connected to the Peltier element (9) is in contact and the boiler (2) is designed so that when assembled and filled with a liquid refrigerant, the liquid refrigerant within the boiler (2) covers the entire part of the first side wall (2c) that is connected to the Peltier element (9) is in contact and the boiler (2) is designed so that the boiler (2) can only be partially filled with the liquid refrigerant, characterized in that the boiler (2) is cuboid and in the assembled state both the Peltier element (9) and the first side wall (2c) are predominantly flat and arranged in a plane inclined by 1° to 3° from a vertical plane, so that the Peltier element (9) and the first side wall (2c) are at the top of the cooling cabinet nk (100) are tilted towards. Thermoelectric cooling unit (1) after claim 1 , characterized in that the heat pipe (7) is just a single continuous tube without branches. Thermoelectric cooling unit (1) after claim 1 or 2 , characterized in that the heat pipe (7) is provided on its outside with a plurality of wires (14). Thermoelectric cooling unit (1) according to one of Claims 1 until 3 , characterized in that the outlet connection (4) is arranged in the assembled state on a top (2a) of the boiler (2) and the heat pipe (7) from the outlet connection (4) away and leads upwards. Thermoelectric cooling unit (1) according to one of Claims 1 until 4 , characterized in that the heat pipe (7) extends at least partially in serpentine form. Thermoelectric cooling unit (1) according to one of Claims 1 until 5 , characterized in that in the assembled state of the return connection (5) on an underside (2b) of the boiler (2) angeord net and leading the heat pipe (7) away from the return port (5) and down. Thermoelectric cooling unit (1) according to one of Claims 1 until 6 , characterized in that the heat pipe (7) extends predominantly within one plane or within at least two parallel planes. Thermoelectric cooling unit (1) after claim 7 , characterized in that in the assembled state, the one plane or the at least two parallel planes, within which the heat pipe (7) mainly extends, are arranged vertically. Thermoelectric cooling unit (1) according to one of Claims 1 until 8th , characterized in that the heat sink (8) is at least partially plate-shaped and is in contact with the Peltier element (9) on one side of the plate shape. Thermoelectric cooling unit (1) after claim 9 , characterized in that the thermoelectric cooling unit (1) further comprises fastening means (3) for fastening the boiler (2) to the heat sink (8), whereby the Peltier element (9) is clamped between the boiler (2) and the heat sink (8). becomes. Thermoelectric cooling unit (1) after claim 10 , characterized in that there are at least four fastening means (3) arranged around the Peltier element (9) in a plan view of the plate-shaped portion in contact with the Peltier element (9). Thermoelectric cooling unit (1) after claim 10 or 11 , characterized in that the fastening means (3) are hooks (20) which protrude from the side of the boiler (2) through holes (21) in the heat sink (8) and hook onto the other side of the heat sink (8). Thermoelectric cooling unit (1) after claim 9 , characterized in that the thermoelectric cooling unit (1) further comprises an accommodating portion (22) for accommodating the Peltier element (9) and for preventing the Peltier element (9) from moving along the surface of the plate mold fitted with the Peltier element (9) in Contact is included. Thermoelectric cooling unit (1) after claim 10 and 13 , characterized in that the fastening means (3) and the receiving area (22) are integrated in the boiler (2), which is mainly made of a plastic material. Thermoelectric cooling unit (1) after Claim 14 , characterized in that the boiler (2) has an aluminum plate (23) as the first side wall (2c), so that in operation only the aluminum plate (23) between the hot side (9b) of the Peltier element (9) and the refrigerant located. Thermoelectric cooling unit (1) after claim 15 , characterized in that the aluminum plate (23) is already integrated into the boiler (2) during the plastic molding process. Thermoelectric cooling unit (1) after claim 10 and 13 , characterized in that the boiler (2) is held by a housing (24) in which the fastening means (3) and the receiving area (22) are integrated. Thermoelectric cooling unit (1) after Claim 17 , characterized in that the receiving area (22) on the housing (12) is represented by an open area (25) in the housing (12) into which the Peltier element (9) fits. Thermoelectric cooling unit (1) after Claim 18 , characterized in that the housing (12) in the area of the open area (25) has a material thickness which is smaller than the thickness of the Peltier element (9). Thermoelectric cooling unit (1) after claim 19 , characterized in that the housing (12) has pressing means (19) located near a second side wall (2d) of the boiler (2) opposite to the first side wall (2c). Thermoelectric cooling unit (1) after claim 20 , characterized in that the pressing means (19) comprise a screw (26) or a bolt which passes through the housing (12) and acts on the center of the second side wall (2d) of the boiler (2) to fix the boiler (2nd ) with its first side wall (2c) to press the Peltier element (9). Refrigerator (100) with a thermoelectric cooling unit (1) according to one of the preceding claims, wherein during operation the cold side (9a) of the Peltier element (9) communicates with the interior of the refrigerator (100) via the heat sink (8) and the hot side (9b) of the Peltier element (9) with the environment via the boiler (2) and the heat pipe (7) in heat exchange, and wherein the boiler (2) is only partially filled with a liquid refrigerant and the liquid refrigerant inside the boiler (2) the entire part of the first Side wall (2c) covered, which is in contact with the Peltier element (9).

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