Patent Application
20090314007
The present invention relates to a refrigerator unit and/or a freezer unit having an inner container for the reception of refrigerated goods and/or frozen goods, having a magnetic cooler as well as having a heat exchanger for the cooling of the inner space of the inner container.
Refrigerator units and/or freezer units of a conventional kind are known from the prior art which have a refrigerant circuit with a compressor, condenser, restrictor and evaporator, with the evaporator serving to cool the inner space by evaporating the refrigerant.
It is furthermore known from the prior art to use a so-called magnetic cooler to cool the inner space of a refrigerator unit and/or freezer unit. Different operating principles are known for such magnetic coolers.
For example, the magnetic cooler can be made of a magnetocaloric material which is heated on its magnetization and which undergoes cooling on its demagnetization. If the heat carrier medium flows through the magnetized, and thus heated, part of the magnetic cooler, it is heated. The heat carrier medium then flows through a hot heat exchanger which is located, for example, on the outer side of the unit and which is cooled by a suitable coolant.
The heat carrier medium flowing through the demagnetized, and thus cooled, region of the magnetic cooler is cooled. The heat carrier medium cooled in this manner then moves to the so-called cold heat exchanger which is arranged such that it cools the inner space of the device.
It is known in this respect to move magnets relative to the magnetic cooler or its heat exchanger or to switch magnets on and off periodically. The named movement can take place in linear or also rotary fashion. It is also conceivable not to move the magnets, but rather to move the heat exchanger of the magnetic cooler relative to the magnet.
Provision is made in accordance with a further functional principle that particles made from magnetocaloric material are introduced into the heat carrier medium and the heat carrier medium is then heated in that the magnetocaloric materials is magnetized and is thus heated. Cooling is achieved in that the magnetocaloric material is demagnetized, whereby a temperature reduction of the magnetocaloric material and also of the heat carrier medium occurs.
Any desired kind of embodiment or of the functional principle is covered by the invention.
The prior art is that the heat exchanger in the form of an aluminum plate (pipe on sheet metal or roll bond) is fixed in foam using tape adhesive on both sides on the rear wall of the inner container, i.e. of the refrigerated goods container. To obtain a mechanically and thermally adequate connection between the heat exchanger and the inner container, the heat exchanger has to be pressed on mechanically.
The heat transition thus takes place between aluminum, the named tape adhesive on both sides and the inner container.
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 it has a comparatively simple structure and allows efficient cooling.
This object is solved by a refrigerator unit and/or a freezer unit having the features of claim 1 as well as by a refrigerator unit and/or a freezer unit having the features of claim 2.
In accordance with the invention, provision is made in accordance with claim 1 that the heat exchanger is arranged such that the heat transfer from the inner space of the inner container to the heat carrier medium only takes place via the wall of the inner container or only via the wall of the heat exchanger. Differing from the arrangement known from the prior art, the heat transition consequently only takes place via one of the named walls and is therefore particularly effective.
In accordance with the invention, provision is made in accordance with claim 2 that the heat exchanger is an integral component of the inner container or that the heat exchanger is in direct communication with the inner container.
The wall or walls through which the heat is transmitted from the inner space of the unit to the heat carrier medium can comprise means by which the heat transfer is improved. A suitable coating or the presence of a medium in the wall which improves the heat transfer can be considered. The introduction of solids which have good thermal conductivity is conceivable. The use of metals or metal alloys is preferably provided. It is thus for example, conceivable that the wall comprises metal particles and/or other solids having good thermal conductivity which are distributed in the plastic material and have the purpose of improving the passage of heat through the wall.
Embodiments are thus covered by the invention, for example, in which the heat exchanger forms an integral component of the inner container, i.e. is in communication with it in one piece. The fact that the heat exchanger is directly in communication with the inner container is also covered by the invention. Such a direct connection can be realized, for example, by an ultrasound method.
The heat exchanger can be arranged on the side of the inner container directed toward the inner space or also on the side of the inner container directed outwardly. It can also be arranged such that it forms part of the inner container.
It is conceivable that the heat exchanger is made as a pan. This pan can be arranged or shaped as desired.
It is, for example, conceivable that the heat exchanger is made such that the heat carrier has to flow through a passage or through a passage system. In this respect, the passage system is preferably made such that the passage is directly adjacent to the inner container so that the heat transfer only takes place via the inner container. Since, in this embodiment of the invention, the heat exchanger is not indirectly connected to the inner container, for example not by means of adhesive tape, but is rather directly connected to the inner container, the heat transfer only has to be carried out via the inner container material, whereby particularly efficient cooling results.
It is also conceivable, for example, to make the heat exchanger as a pipe or as a pipe-like system. It is, for example, possible in this respect that the heat exchanger is integrated into the inner container such that the pipes form a section of the inner container or extend in a certain section of the inner container. In this case, the heat transfer only takes place via the pipe wall, whereby an efficient heat transfer likewise results.
As already stated above, the heat exchanger can be fixed to the inner container by means of ultrasound. Other methods are naturally also conceivable by means of which a direct connection can be made between the heat exchanger, on the one hand, and the inner container, on the other hand.
Provision is made in a further embodiment of the invention that the heat exchanger is in communication with pipes for the supply and drainage of heat carrier medium into and out of the heat exchanger and that one or both of these pipes are made from plastic. Provision is preferably made that the heat exchanger is made primarily or exclusively of plastic.
The making of the connection pipes between the cold heat exchanger and the magnetic cooler from plastic saves costs in the same way as the making of the heat exchanger from plastic. Apart from this, the recycling of PS material is more convenient than that of aluminum.
An embodiment of the invention will be shown in the following.
The heat exchanger of the cold side comprises a type of pan which is fixed directly to the inner container, i.e. to the refrigerated goods container, by means of an ultrasound process. The heat carrier flows between the refrigerated goods container and the heat exchanger pan.
The heat exchanger pan can have any desired shape so that the heat carrier has to flow through a kind of passage, for example.
The heat transfer only takes place via the inner container.
Alternatively to this, it is also conceivable that the heat exchanger forms an integral component of the inner container which is arranged, for example, on the inner side of the inner container or on the outer side of the inner container or which forms an integral component of the inner container wall.
The aforesaid kind of heat exchanger is possible with refrigerator units and/or freezer units in connection with a magnetic cooler because no real positive pressure is present in the system.
As stated above, the connection pipes to the magnetic cooler can moreover be made from plastic. This saves costs and apart from this the recycling of the material used is comparatively convenient so that a cost advantage also results from this.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20 2006 017 168.1 | Nov 2006 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2007/009598 | 11/6/2007 | WO | 00 | 5/8/2009 |
