Patent Application
20120090820
The invention relates to a temperature-control device, in particular for refrigerators, buildings or the like, with at least one heat exchanger having at least one energy transmission body, through which an energy transmission medium is conducted, and to a heat exchanger therefor and to a method for the production of the latter.
DE 18 02 234 discloses a heat exchanger for refrigerators, in which a tube through which a liquid medium flows and which is in the form of a tube coil or flat tube register is connected fixedly and in a heat-conducting manner to heat-exchange plates, between which connecting points are slotted. The sheet-metal strips are each fully pressed out of the plane of the plate in an alternating manner to different sides of the heat exchanger plate.
DE 10 03 236 C1 discloses a tube coil evaporator for refrigerators and the like, wherein the refrigerant line sections, which cover the sides of an evaporator housing, are each laid on that surface of the relevant side wall which faces the evaporation space and, in the case of a square housing cross section, are optionally also laid on the inner surface of the top wall of the housing. The line section assigned in each case to the floor of the housing consistently runs on that outer surface thereof which faces the room to be cooled.
A heat exchanger made of plastics material consists, according to DE 32 46 919 A1, of thin-walled flexible rigid PVC ribbed tubes. The ribbed tubes emerge from a distributing tube and correspondingly lead into a collector tube. The ribs are of hollow design and have an open connection toward the cavity of the tube. A special design involves hollow ribs, the angle of inclination of which with respect to the tube axis is smaller than 90°. The heat exchanger serves, for example suspended in the pointed arch of a roof, for heating of a swimming pool or for preheating of water for domestic use.
DE 103 38 318 B4 discloses a latent heat accumulator with a heat exchanger consisting of composite plastics material and metal capillary tubes which are arranged parallel to one another in mats and the ends of which are each combined in a collecting tube. Each of the composite plastics material and metal capillary tubes consists of an inner plastics material capillary tube having a diameter of approximately 1 mm to 7 mm with a wall thickness of 50 μm to 1.5 mm, onto which a foil, which is applied over the full surface area and has a thickness of approximately 19 to 500 μm, is adhesively bonded as a diffusion barrier and so as to overlap.
A disadvantage in the previously known documents is that the heat exchange is undertaken via conduits. The tubes, due to the round cross section thereof, only transmit the energy over a very small contact area, thus resulting in low energy transmission efficiency.
EP 0 979 981 A1 discloses a solar collector, in which an energy transmission medium is guided between two layers of plastics materials.
DE 10 2005 029 051 A1 discloses a heat-conducting device for floor, wall or ceiling heating, in which a heat-conducting body element is formed from graphite expandate which has reduced heat conductivity perpendicularly to the two-dimensional extent of the heat-conducting body element.
JP-A-2007255728 discloses a heat exchanger in which a heat-exchange line is guided between an insulator and, for example, a metal layer.
It is therefore the object to develop a temperature-control device of the type mentioned at the beginning and a heat exchanger itself in such a manner that, in particular, the energy transmission efficiency is improved.
The object on which the invention is based is in each case achieved by the features of the independent patent claims. Embodiments of the invention are specified in the dependent patent claims.
According to embodiments of the invention, the plastics heat exchanger is formed by a heat-conducting body element and a heat-insulating body element, wherein the heat-conducting body element has greater heat conductivity than the heat-insulating body element. At least one energy transmission body for passage of an energy transmission medium is formed between the heat-conducting body element and the heat-insulating body element.
For example, the heat-conducting body element and the heat-insulating body element are two plastics parts, in particular two shaped bodies made of plastics material, which are produced separately, for example, by injection molding of the plastics material or by extrusion and are then connected to each other in order to form the plastics heat exchanger. The heat-conducting body element and the heat-insulating body element can be connected, for example, in a form-fitting and/or integrally bonded manner, for example by welding. However, the heat-conducting body element and the heat-insulating body element may also be produced as a single piece in one working operation, specifically, for example, by means of co-extrusion or a multi-component plastics injection molding process.
The insides of the heat-conducting body element and of the heat-insulating body element may be shaped in such a manner that, owing to the heat-conducting body element and the heat-insulating body element being joined together, the energy transmission body or bodies for the passage of the energy transmission medium is or are formed; no further, separate components are then required for the formation of the energy transmission bodies within the plastics heat exchanger.
According to an embodiment of the invention, the energy transmission bodies are formed by tubular hollow elements, for example, made of plastics material, which are arranged in cavities formed by the joined-together heat-conducting bodies and heat-insulating body elements. Said hollow elements may be formed from a conductive plastics material of high heat conductivity greater than the heat conductivity of the heat-insulating body element.
According to a further embodiment of the invention, one of the hollow elements is formed by two partial-body hollow elements, one of which has great heat conductivity and one has lower heat conductivity, wherein the partial-body hollow element having lower heat conductivity bears against the heat-insulating body element.
According to an embodiment of the invention, the heat-conducting body element contains a plastics material having anisotropic heat conductivity. For example, the heat-conducting body element is a plastics injection molded part or a plastics co-extrusion part made of the anisotropically heat-conductive plastics material. The heat conductivity of the plastics material has a preferred direction in which the heat conductivity is increased in comparison to other directions.
According to an embodiment of the invention, the plastics heat exchanger has at least two energy transmission bodies which are spaced apart from each other and run transversely with respect to the preferred direction. For example, the energy transmission bodies run parallel to each other under a front side of the heat-conducting body element. The anisotropically conductive plastics material then has a preferred direction transversely, preferably perpendicularly, with respect to the longitudinal direction of the energy transmission bodies, i.e. the direction of flow of the energy transmission medium. This has the advantage that the heat in the intermediate space between two adjacent energy transmission bodies is readily conducted such that a relatively large part, preferably the entire surface, of the heat-conducting body element is used efficiently for the transmission of heat, rather than just the regions in the vicinity of the energy transmission bodies.
According to the invention, this object is achieved in a temperature-control device
The advantages obtained by the invention consist in particular in that the energy transmission bodies are formed in two parts from plastics material. This makes it possible to realize cross sectional shapes permitting planar contact with the transmission side. The energy-conducting body adjoining the conductive partial-body hollow elements reinforces the transmission efficiency. By contrast, the heat-insulating body element adjoining the non-conductive partial-body hollow elements increases the insulating effect. By this means, the transmitted energy is used in a more specific manner. This revolutionizes the design of a refrigerator while simultaneously reducing the production costs. The term refrigerator covers freezer compartments and holding compartments in refrigerators and the like, and also chest freezers.
The plastics heat exchanger can be of modular design. By this means, it is possible to install a corresponding number of groups of energy transmission bodies of two-part design in a manner matched to the particular body wall.
The object is achieved in a heat exchanger in that the energy transmission bodies consist of first partial-body hollow elements made of a conductive plastics material having heat conductivity of approx. 1.0 to 50.0 [W/(mK)], on which second partial-body elements made of a plastics material having heat conductivity of approx. 0.001 to 1.0 [W/(mK)] are arranged.
The advantages which are obtained therewith consist in particular in that the design of refrigerators, room heating systems, air-conditioning systems and building supply systems obtains a new quality. The design thereof is simplified and the transmission efficiency and the insulating effect improved.
The heat exchanger may be, firstly, an evaporator for refrigerators or the like, in which a refrigerant or the like flows through the energy transmission bodies. Secondly, the heat exchanger may be a heat transmission medium, in which a heated liquid outputs heat to the environment in a specific manner via an energy medium. The heat exchanger may furthermore be a solar collector, in which a heat-exchange medium, for example water or the like, is heated by sun rays and heat energy is thus absorbed.
A heat-insulating body element made of an insulating plastics material having heat conductivity of approx. 0.001 to 1.0 [W/(mK)] can be arranged on the second partial-body hollow elements.
An energy-conducting body made of a further conductive plastics material having heat conductivity of approx. 1.0 to 50.0 [W/(mK)] can be at least partially arranged on the first partial-body hollow elements.
For further insulation, an insulating-body element made of a further insulating plastics material having heat conductivity of approx. 0.001 to 1.0 [W/(mK)] can be arranged on the heat-insulating body element.
However, the first partial-body hollow elements may also consist of a conductive plastics material having heat conductivity of approx. 2.0 to 10.0 [W/(mK)], and the second partial-body hollow elements may consist of a plastics material having heat conductivity of approx. 0.1 to 1.0 [W(mK)].
The energy-conducting bodies may be produced from a conductive plastics material having heat conductivity or from an insulating plastics material having heat conductivity of approx. 0.0015 to 0.3 [W(mK)].
The first partial-body hollow element and the energy-conducting body may be produced from a conductive plastics material of identical heat conductivity. As a result, said parts are a unit not only in terms of manufacturing but also in terms of heat.
A panel element can be arranged on the energy-conducting body, i.e. the heat-conducting body element, in particular on the front side thereof. The panel element may consist of an unfilled or unfilled plastics material, a metal, or of another material, such as wood, fleece, wallpaper, . . . or the like. By this means, a multi-layered composite is possible.
According to an embodiment of the invention, a front side of the heat-conducting body element is designed as a large surface. In particular, a room which is to be cooled or heated can be bounded or enclosed by the heat-conducting body element. This is particularly advantageous for applications only having free convection.
The first partial-body hollow elements may be of partially rectangular design in cross section. By this means, and by means of the smooth joining surface to the transmission space, for example a refrigerator, optimum energy transmission in the form of cold or, in other applications, in the form of heat, is provided.
The second partial-body hollow elements may be of
If the energy transmission bodies are composed of a partially rectangular first partial-body hollow element and
The cross sectional shapes are not solely restricted to these geometrical shapes. Which cross sectional shape is used depends on the intended use of the heat exchanger and on the space conditions.
A multiplicity of plastics materials can be used for the construction:
As already mentioned, the panel element may consist, inter alia, of an unfilled plastics material.
That is to say, the panel element may consist of an unfilled plastics material or the like. The plastics material may be a thermoplastic material, in particular polystyrene, a polystyrene blend, a polyolefin, a polyester, a polyamide, a biodegradable plastics material or the like.
The insulating plastics material may be a plastics material foamed with air, CO2 or similar gas.
The conductive and the further conductive plastics material may be a plastics material which is filled with metal powder, ceramic powder, graphite, aluminum oxide, boron nitride, metal fibers and/or nanomaterials.
The metal powder may be an aluminum powder, a copper powder or similar powder.
The ceramic powder may be a BN powder, an Al2O3 powder, a silicate powder or similar powder.
The object is furthermore achieved in a method for producing a heat exchanger by use of a plastics material composite such that the energy transmission bodies are formed from first partial-body hollow elements made of a conductive plastics material having heat conductivity of approx. 1.0 to 50.0 [W/(mK)], on which second partial-body elements made of a plastics material having heat conductivity of approx.0.001 to 1.0 [W/(mK)] are integrally formed.
The integral forming operation may advantageously be extrusion.
The advantages associated therewith consist in particular in that, for the forming of the energy transmission bodies, use is made of a tool which determines the desired cross section. During the extrusion, the two plastics materials used flow together at the separating point and form a uniform composite which, above all, can withstand mechanical loadings and ensures reliable tightness.
An energy-conducting body made of a further conductive plastics material having heat conductivity of approx. 1.0 to 50.0 [W/(mK)] can be integrally formed on the first partial-body hollow elements.
The first partial-body hollow element and the energy-conducting body may be formed from a conductive plastics material having heat conductivity.
This improves and standardizes the overall conductivity. Furthermore, the production operation is simplified.
The first partial-body hollow element and the energy-conducting body can be formed from an identical conductive plastics material of substantially identical heat conductivity.
The first partial-body hollow elements, the energy-conducting body and a panel element can be formed as a multi-layered composite.
The invention is illustrated in the drawing and is described in more detail below. In the drawing
As
Any number of energy transmission bodies 10.1, . . . may lie next to and/or above one another. The arrangement thereof and the number thereof are determined by the specific energy transmission tasks.
The heat conductivity λ is measured here in [W/(mK)] where
The partial-body hollow elements 11.1, . . . , 11.n are at least partially enclosed toward the interior 5 by a heat-conducting body 13 made of a conductive plastics material having heat conductivity λ of approx. 1.0 to 50, preferably 2.0 to 10.0 [W/(mK)]. The heat-conducting body reaches here approximately to level with the conductive partial-body hollow elements 11.1, . . . , 11.n.
Alternatively, in a plastics heat exchanger 1 according to
The conductive plastics material may be a plastics material which is filled with a metal powder, for example aluminum powder, graphite, aluminum oxide, boron nitride, metal fibers and/or nanomaterials.
The plastics material for the partial-body hollow elements 12.1, . . . is an unfilled plastics material which may be a thermoplastic material, in particular polystyrene, a polystyrene blend, a polyolefin, a polyester, a polyamide, a biodegradable plastics material or the like.
During the forming of the energy transmission bodies 10.1, . . . a tool determines the desired cross section. During the extrusion, the conductive and the non-conductive plastics materials flow together at the separating point and thus form a standardized composite which, above all, can withstand mechanical loadings and is impermeable.
The energy transmission bodies 10.1, . . . according to
The cross section is essentially determined partially by the cross section of the partial-body hollow elements 12.1, . . . According to
It is essential that the partial-body hollow elements 11.1, . . . by means of the rectilinear base surface thereof ensure the best possible energy transmission, and, in the case of a refrigerator, transmission of cold from the refrigerant 2.
The heat-conducting body 13 is adjoined by a panel element 4.
The panel element 4 can be composed of a metal or of another material, such as wood, fleece, wallpaper, . . . or the like.
The panel element 4 may be an unfilled plastic, i.e. a polystyrene, a polystyrene blend or the like.
In this case, the partial-body hollow elements 11.1, . . . , 11.n, the energy-conducting body 13 and the panel element 4 can be formed as a multi-layered composite.
In order to reinforce the insulating effect of the partial-body hollow elements 12.1, . . . , the latter are adjoined, as
According to an embodiment of the invention, the heat-conducting body element, i.e. the heat-conducting body 13, contains a plastics material having anisotropic heat conductivity. The anisotropic heat conductivity has a preferred direction 26 in which the heat conductivity is increased in comparison to other directions. For example, the plastics material of the heat-conducting body element 13 contains a nanoscale filler, in particular carbon nanotubes. Nanoscale fillers of this type are known per se from the prior art (cf. Kunststoffe [Plastics], December 2009, “Wärme besser leiten” [Better heat conduction], Carl Hanser Verlag, Munich).
In this embodiment, the energy transmission bodies are arranged in such a manner that they run perpendicularly to the preferred direction 26 of the anisotropically heat-conductive plastics material. This has the advantage that the heat is readily conducted in the intermediate spaces between the energy transmission bodies, and therefore the heat exchange is not restricted to those regions of the panel element 4 which are arranged in the immediate vicinity of one of the energy transmission bodies, but also includes the regions between the energy transmission bodies. This makes better use of the area of the panel element 4, thus resulting in greater heating or cooling power.
In the case of the refrigerator 6 in
The partial modules may be connected to one or more cooling compressors or the like. By this means, the compartments in the refrigerator can be cooled to differing degrees and can thus be optimally adapted to the particular product being cooled.
Using the same design, the partial modules may also be installed in such a manner that they take on the cooling of the cooling unit as heat exchanger, i.e. coolers. In this case, further heat-conducting elements are also arranged as heat-dispensing elements on the heat-conducting body 13.
The plastics heat exchanger revolutionizes the design of refrigerators 6. The inner coolant evaporator and the outer cooler unit undergo a completely new design which permits simpler manufacturing and ensures greater efficiency by means of the surface energy transfer of cold or heat.
The individual parts of the temperature-control device and of the heat exchanger can be manufactured individually and then welded on and/or adhesively bonded on by means of an integral bond. However, they may also be entirely or partially extruded on. In this case, good heat transfer in conjunction with good mechanical behavior is ensured.
The use of the plastics heat exchanger 1.1, . . . , 1.n does not remain restricted only to refrigerators.
As
The heat exchangers, particularly because of the possible flat design thereof, can be installed easily on the walls below the wall covering in the form of a wallpaper, a material lining, paneling or the like. The thickness of the heat exchanger(s) and of the plaster can be kept approximately identical.
If the building interior 20 is to be cooled, a refrigerant flows through the energy transmission bodies 10.1, . . . , 10.n, and if heating is desired, a heated fluid, for example: hot water, flows therethrough. All of the and/or groups of energy transmission bodies 10.1, . . . can be used for this purpose.
The building interior 20 can thus be steplessly kept constant to, for example: a desired 20° C. The plastics heat exchangers can be designed as main modules 7 and/or partial modules 8.1, 8.2.
A further application of plastics heat exchangers 1.1, . . . is radiant ceiling heating according to
The water flowing in the energy transmission bodies 10.1, . . . , 10.n is heated by the sun and the ambient temperature and is thus constantly available, in particular in summer, for use as washing water, bath water or the like. This enables the overall energy consumption to be reduced.
In winter, water preheated by the energy transmission bodies can be pumped. The surface of the roof 24 is therefore heated over a large surface area. As a result, failing snow immediately thaws and thus prevents overloading of the roof and hazardous avalanches. In this case, a snow brake needs to be fitted only for support.
In summary, it can be established that the plastics heat exchangers
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2009 017 200.9 | Apr 2009 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP10/54700 | 4/9/2010 | WO | 00 | 12/16/2011 |
