Finned heat exchanger

Abstract

The invention relates to a finned heat exchanger, wherein the manufacturing effort is reduced compared to a conventional round-tube heat exchanger for the same heat transfer capacity. The problem addressed is solved with a finned heat exchanger in which the finned structure consists of a continuous sheet of metal that is slotted and bent in such a way that connecting webs are located approximately at mid-height between the fins, above which the fins are interrupted. A meander in the tube bent from a single piece can be placed in these interruptions and connected, e.g. glued, to the connecting webs with good thermal contact.

Description

[0001] Fin heat exchanger

[0002] The invention relates to a finned heat exchanger for heat transfer between a gaseous medium and a second medium, comprising a pipe for the second medium and fins arranged transversely thereto, usually made of aluminum, for increasing the surface area for the gaseous medium, wherein the fins each have recesses for receiving the pipe.

[0003] Furthermore, the invention relates to a finned heat exchanger for heat transfer between a gaseous medium and a second medium, with

[0004] - a pipeline for the second medium extending in a z-direction,

[0005] - a lamellar structure consisting of a continuous sheet of metal that is alternately bent upwards and downwards,

[0006] - wherein the lamellar structure comprises a plurality of lamellae arranged transversely to the z-direction and spaced apart from each other by gaps in the z-direction to increase the surface area for the gaseous medium,

[0007] - the slats each have a lower edge and an upper edge,

[0008] - wherein the lower edges of the slats lie in a base plane extending in the z-direction and in an x-direction arranged transversely thereto,

[0009] - the lamellar structure has open spaces between the lamellae for the gaseous medium in the x and y directions,

[0010] - The sheet metal is provided with slots separating the fins from connecting webs, and the fins have interruptions above the connecting webs, between which recesses are arranged. With such a finned heat exchanger, heat transfer from the gaseous medium, e.g., air, to the second medium is possible in both directions, i.e., the gaseous medium is cooled or heated. The second medium can also be gaseous or liquid, or can undergo a phase change during heat transfer, i.e., evaporate or condense.

[0011] Such finned heat exchangers are required in many different applications, e.g. as a cooler for cooling a liquid medium with air or as a heat exchanger of an air-to-water heat pump for extracting heat from the ambient air or, if the heat pump or air conditioning system is used to cool a building, for releasing heat to the ambient air.

[0012] Typically, finned heat exchangers with an enlarged surface area relative to the air or gaseous medium are used for this purpose. Various designs for surface enlargement are used, with two different types of finned heat exchangers being the most common:

[0013] Round tube fin heat exchanger: The fins are perpendicular to the round tubes through which the second medium flows, see, for example, https: / / www.polarkaeltetechnik.de / pdf / Polar_Lamellenwaerrnetau- scher_DE_EN.pdf

[0014] Rectangular or flat channel or microchannel heat exchanger with folded fins between the rectangular channels through which the second medium flows, see e.g. https: / / youtu.be / SPPtDqOzc-s

[0015] A special application of finned heat exchangers is described in EP 3 497 381 B1 for a PVT collector (photovoltaic thermal collector): A round-tube finned heat exchanger is located on the back of a PV module. The fins rest on the PV module in thermally conductive contact and are glued to the PV module to ensure contact. The fins increase the surface area exposed to the ambient air compared to the surface of the photovoltaic module, thus improving heat exchange compared to conventional PVT modules. Clearances of typically 10-50 mm are provided between the fins to allow good airflow around both the heat exchanger and the back of the PV module, and to prevent the gaps from becoming blocked by icing.The pipes are located at a certain distance from the PV module, for example in the middle between the outer edge of the fins and the PV module in order to optimize the heat transfer from the air and to minimize possible icing of the PV module.

[0016] A general disadvantage of round-tube finned heat exchangers is the relatively complex manufacturing process, which involves numerous steps: The fins are punched from a sheet metal, holes with collars are cut out for the round tubes, the round tube is bent into U-bends, the fins are threaded onto the U-bends, the round tubes are expanded using inserted domes so that the fin collars sit firmly on them, and finally, short 180° bends are soldered onto the open ends of the U-bends. One disadvantage, for example, in the application for the PVT collector described in EP 3 497 381 B1, is that the fin spacing is limited due to manufacturing constraints: the spacing is defined by the collars cut out on the fins, and the collaring is limited to approximately 10 to a maximum of 12 mm for a typical fin thickness of 0.2 mm. In the application mentioned, a larger distance leads to a better free flow around the slats up to the PV module.This means that the amount of material used can be reduced while maintaining the same heat output, and at the same time the possibility of the gaps becoming blocked by icing is minimized.

[0017] A larger fin spacing is particularly necessary if the space between the PV module and the roof, facade or rear wall as in DE 20 2022 000 161 U1 should be as small as possible, since if the air is to flow by free convection, especially between the fins, the flow resistance is too great at a fin spacing of 10-12 mm. Furthermore, studies have shown that lateral air exchange also has a strong positive influence on high heat transfer performance. However, due to the closed shape, cross-flow in the z-direction is not possible between the fins, only behind the fins, e.g. between the fins and the roof, which requires a greater distance to the rear wall and leads to poorer heat transfer than if the air could flow directly crosswise between the fins.

[0018] DE 20 2015 103 440 U1 describes a finned heat exchanger which, in contrast to the method described above, uses at least one aluminum tube meander formed from a single piece. Fins referred to as guide vanes are arranged one behind the other between pipe sections in the longitudinal direction of the pipe sections. These guide vanes have receptacles on one side of the edge, on which collars extending in the longitudinal direction of the pipe sections are arranged, against which respective wall sections of the pipe rest. The guide vanes are integrally bonded to the wall sections of the pipe in the area of ​​the collars. A disadvantage of this heat exchanger design is the relatively high manufacturing effort required for the precise arrangement of all the individual fins or guide vanes on both sides of the pipe, despite the pipe being bent into a meander shape from a single piece.

[0019] DE 10 2015 120 487 A1 also describes a finned heat exchanger with a single-piece, meandering pipe. Here, folded fins are used, as in the microchannel heat exchangers described above, but combined with a round pipe: folded fins with embossed collars are attached to both sides of the pipe. The disadvantage of this arrangement is that the gaseous medium can only penetrate from the outside to the center, where the fin folds, which precludes, for example, an application such as that described in EP 3 497 381 B1. DE 10 2017 112 063 A1 shows a finned heat exchanger in which a pipe intended for heat transfer is also enclosed on both sides by two wave-folded fin structures. In this case, the wave-shaped slats are located at the fold or the edge, as in DE 10 2015 120 487 A1.Bending is closed in each case, so that here too the gaseous medium can only penetrate from the outside to the middle, with the same disadvantage as in DE 10 2015 120 487 A1.

[0020] From DE 27 28 472 A1, a finned heat exchanger of the type mentioned above is known, which also provides fins connected to one another by an accordion-like folding, with semicircular collars for the contact surface to the heat exchanger pipe. This finned heat exchanger has two folded fin structures which, during manufacture of the finned heat exchanger, are placed on the pipe from both sides and are connected to one another by hooks bent into the finned sheets. The disadvantage of this arrangement is the effort involved: two fin structures are always required, which must be connected to one another. Furthermore, the connecting webs which connect the fins at the top and bottom ends hinder the free exchange of air between the fins, especially in the y-direction, see, for example, page 8, third paragraph of this document. This would be particularly useful in applications with free convection, such asThis can have a negative effect on a structure according to EP 3 497 381 B1, where the air is also intended to enter perpendicular to the arrow shown in Figure 15, ie, from top to bottom. If the webs are made narrow to minimize the obstruction, the unit becomes fragile, which, among other things, makes efficient production difficult.

[0021] A further disadvantage, as with DE 20 2015 103 440 U1, is that punching with waste is required to create the finned structure, meaning that the processed sheet surface is not fully utilized as the heat exchanger surface. Round-tube finned heat exchangers in building heating and cooling applications, when a fluid flows through them, are often manufactured with copper tubes and aluminum fins. This is because copper tubes offer greater corrosion resistance than, for example, aluminum tubes, especially in mixed installations—i.e., when different metals are used in the same hydraulic circuit. Bent copper tubes can also be manufactured with thinner walls than aluminum tubes, so the cost difference compared to aluminum tubes is not significant, depending on the metal price.However, a disadvantage of the combination of copper pipe with aluminum fins is the increased risk of corrosion at the contact points between copper and aluminum, which is why such heat exchangers for applications in corrosive environmental conditions are usually equipped with a coating, which in turn increases the costs.

[0022] Microchannel heat exchangers can be produced with fewer work steps and therefore lower manufacturing costs. A disadvantage of microchannel heat exchangers is the relatively high material expenditure required to manufacture the rectangular channels, as certain wall thicknesses cannot be achieved in the extrusion process. The application for the PVT collector described in EP 3 497 381 B1 is only possible without folded fins, as otherwise the air cannot flow freely between the channels. In this application, the surface area required for heat transfer would therefore have to be created by a correspondingly large number of microchannels, and the material input would be significantly larger than for a round-tube fin heat exchanger with the same area. In addition, a MicroChannel directly cools the PV module, which can lead to unwanted icing.

[0023] The object of the invention is to provide a finned heat exchanger according to the preamble of patent claim 1 or patent claim 10, in which the manufacturing effort is reduced compared to a conventional round-tube finned heat exchanger with respect to the same heat transfer capacity. Furthermore, the finned heat exchanger should enable low material costs during its manufacture.

[0024] Corrosion risks should be minimized even without coating. For applications involving natural convection during external heat transfer, a larger fin spacing than 10 to 12 mm should be feasible, and the external heat transfer, which represents the greatest resistance in the entire thermal resistance chain, should be improved compared to a conventional round-tube finned heat exchanger: Crossflow between the fins in the z-direction should be possible.

[0025] The above-mentioned object is achieved with regard to a finned heat exchanger according to the preamble of patent claim 1 in that the recesses are designed as receptacles for the pipeline and that the pipeline is arranged in the recesses.

[0026] The slats, including the defined spacers created by the connecting webs, can be manufactured using a continuous process from a single piece of sheet metal, for example, unrolled from a roll. During the production of the slat structure, the sheet metal can be slit, for example, using a stamping process, and then pressed into a zigzag shape.

[0027] The pipe can be designed as a meander pipe bent from a single piece, which is inserted into the interruptions of the fins and into the recesses arranged between them during the manufacture of the finned heat exchanger and is connected to the connecting webs in a material or form-fitting manner with good thermal contact.

[0028] The sheet metal is provided with slots that separate non-bent sections of the sheet metal, forming vertical or inclined lamella sections, from bent sections, forming connecting webs. Since, in the thermal resistance chain, particularly in the case of free convection, the heat transfer between air or gaseous medium and lamella represents the greatest thermal resistance, improvements are most effective here, while deteriorations, e.g., due to gluing of the pipe and lamellae instead of a metallic connection or a plastic layer on the inside and, if appropriate, outside of the pipe, have comparatively little impact if dimensioned accordingly. Therefore, in a preferred embodiment of the invention, the lamella structure comprises at least two parallel rows of lamellae, in each of which several lamellae are arranged one behind the other, offset from one another in the z-direction, and

[0029] - that the lower edges of the slats of a first row of slats are offset from each other in the z-direction with a gap between them and the lower edges of the slats of a second row of slats, the slats of which are each connected via a connecting web to a slat of the first row of slats assigned to this slat, and / or

[0030] - that the upper edges of the slats of the first row of slats and the upper edges of the slats of the second row of slats, the slats of which are each connected via a connecting web to a slat of the first row of slats assigned to it, are offset from one another in the z-direction.

[0031] The fins are preferably arranged alternately between the connecting webs, on one or the other side of the connecting web. Due to the offset fins, air flowing parallel to the fins in the x-direction repeatedly encounters a new fin, and air exchange perpendicular to the fins in the z-direction is also more easily possible. This improves the heat transfer between the air or gaseous medium and the fin compared to a conventional round-tube fin heat exchanger design.

[0032] In the embodiment described above, the pipe can also be bent from a single piece using a continuous process and connected to the folded slats in a thermally conductive manner, e.g., by gluing, welding, or soldering, e.g., in a furnace, or by mechanical pressing. To bond the pipe and the slatted sheet, the connecting web can be embossed. The contour of this embossing corresponds to the cross-section of the pipe, ensuring good contact with the pipe. For a round pipe, the embossing is therefore in the shape of a circular segment. Alternatively, the pipe can be shaped so that it has a flattened cross-section at the contact surface with the connecting piece of the slatted sheet, which in this case is flat.

[0033] In an advantageous embodiment of the invention, slats are provided with bevels on their upper and / or lower edges, which provide support surfaces. These support surfaces can be used, for example, for applying adhesive for bonding to a surface, e.g., the surface of a PV module. At the same time, the bevels ensure greater stability of the slat structure.

[0034] It is advantageous if the edges of the slats adjacent to the interruptions have a shape that is geometrically adapted to an outer contour area of ​​a pipeline facing it and is designed in particular as a negative shape of this outer contour area, and if these edges preferably receive the pipeline in a form-fitting manner such that the pipeline is in thermal contact with the connecting web.

[0035] In a further advantageous embodiment of the invention, the connecting webs have a shape that is geometrically adapted to an outer contour region of a pipeline facing them and is particularly designed as a negative form of this outer contour region, wherein the connecting webs preferably rest flatly against the outer contour region of the pipeline. This measure also enables good thermal contact between the pipeline and the lamellar structure.

[0036] In a suitable embodiment of the invention, the connecting webs are flat, with the pipeline having a flattened cross-section that lies flat against the connecting webs. Outside the flattened cross-section, the pipeline can be cylindrical or rounded in some other way.

[0037] It is advantageous if the connecting webs have a preferably tab-shaped widening on at least one side, which is shaped to rest laterally against the pipeline and increase the contact area. The connecting webs can therefore be widened on the sides with wings shaped to rest laterally against the pipeline and thus increase the contact area. The resulting contour of the connecting webs can be designed such that there are areas that do not rest against the pipe and in which adhesive is located, as well as other areas that are in direct contact with the pipe.

[0038] All measures - adjustment of the contour of the connecting web and the cross-section of the pipeline as well as widening of the support surface by means of wings - can be combined with each other.

[0039] Fins and piping can be made of aluminum, preferably corrosion-resistant aluminum, so that an additional coating for corrosion protection is not necessary, especially because there are no contact points between different noble metals.

[0040] The above-mentioned object is achieved with regard to a finned heat exchanger according to the preamble of patent claim 10 in that the pipeline consists of an aluminum-plastic composite pipe with plastic on the inside and a preferably 0.2 mm to 0.5 mm thick aluminum layer on the outside, that the aluminum layer is designed such that it conducts the heat transferred by the fins over the entire pipe circumference and the areas between the fins, and that the pipeline is bent from a single piece. The aluminum-plastic composite pipe has the advantage of corrosion protection, particularly on the inside, e.g. in mixed installations or in installations where it cannot be ruled out with certainty that traces of copper enter the circuit during processing or assembly. Calculations show that a technically feasible plastic layer of approx.

[0041] 0.7...0.8...0.9 mm with a total outer diameter of, for example, 14 mm results in an acceptably small reduction in the total heat transfer.

[0042] For the aluminum layer, as well as for the fins, an alloy sufficiently corrosion-resistant for the application is selected. This eliminates the need for a plastic coating on the outside. This enables good thermal contact between the fins and the pipe, and the heat transferred there can be conducted through the aluminum layer over the entire circumference of the pipe and the areas between the fins and transferred inwards. The connection between the pipe and fins can then be achieved not only by adhesive bonding but also by welding with very limited local heat generation, e.g., by ultrasonic welding or laser welding. With ultrasonic welding, a sonotrode can roll along the underside of the connecting webs on which the pipeline rests. With laser welding, for example, parts of the connecting web can be melted from the outside using the laser beam and welded to the aluminum layer of the pipe.

[0043] The plastic layer inside and an aluminum layer outside allows for a thinner aluminum layer of approximately 0.2 mm to approximately 0.5 mm than with a pure aluminum tube, resulting in lower weight and at least lower material costs, for several reasons:

[0044] - From a manufacturing point of view, thin-walled aluminum tubes with wall thicknesses in the range of 0.3 mm are difficult to produce without a plastic composite.

[0045] - Aluminum composite pipe with a thin-walled aluminum tube can be bent more tightly than a pure aluminum pipe of the same thickness. The corrosion protection and secure sealing provided by the plastic inner tube allow for lower safety and thus lower material thicknesses with aluminum.

[0046] Often, finned heat exchangers also include a distribution and collector pipe or a distribution and collector duct. The connection between the pipeline or the meander pipe and these pipes is usually made by soldering or welding. If the meander pipe and the distribution and collector pipes are both made of aluminum, the connection can be designed as a soldered or welded joint, for example. If the pipeline is an aluminum-plastic composite pipe, a transition piece made of plastic or another material can be attached to both meander ends by (plastic) welding or gluing. This transition piece can also be welded or glued to a distribution and collector pipe made of plastic or aluminum-plastic composite.

[0047] In an advantageous embodiment of the invention, the pipeline is connected to aluminum fins of a finned structure by a weld seam, in particular an ultrasonic or laser beam weld seam. During the manufacture of the finned heat exchanger, the ultrasonic or laser beam weld seam can be introduced into the fin and the pipeline by applying heat in a very limited space.

[0048] Further advantageous embodiments of the invention are described in the subclaims.

[0049] Exemplary embodiments of the invention are explained in more detail below with reference to the drawing. It shows:

[0050] Fig. 1 is an isometric partial view of a first embodiment of a lamellar structure, Fig. 2 is an isometric partial view of a second embodiment of the lamellar structure,

[0051] Fig. 3 is an isometric view showing a larger area of ​​the lamella structure of the second embodiment than Fig. 2,

[0052] Fig. 4a a flat sheet with slots, from which a third embodiment of the lamellar structure can be produced by bending,

[0053] Fig. 4b to 4c an isometric view of the sheet shown in Fig. 4a, showing the sheet in different states of bending deformation,

[0054] Fig. 5 is an isometric partial view of a fourth embodiment of the lamellar structure,

[0055] Fig. 6 is an isometric partial view of a fifth embodiment of the lamellar structure,

[0056] Fig. 7 is an isometric partial view of a sixth embodiment of the slat structure, showing a connecting web widened on both sides by wings,

[0057] Fig. 7a shows a partial cross-section through a finned heat exchanger having the finned structure according to Fig. 7 and a pipe connected to the connecting web in a heat-conducting manner,

[0058] Fig. 8 is an isometric partial view of a seventh embodiment of a lamellar structure,

[0059] Fig. 9 is an isometric view of the piping of the finned heat exchanger shown in Fig. 10, Fig. 10 is an isometric partial view of a finned heat exchanger,

[0060] Fig. 11 is a partial isometric view of a pipeline having a rounded cross-section with a flattened cross-sectional area,

[0061] Fig. 12 is an isometric view of the connection between a meandering pipeline and a distribution or collecting pipe, and

[0062] Fig. 12a shows a cross section through the connection shown in Fig. 12.

[0063] Figure 1 shows a finned structure 1 of a finned heat exchanger 9 (shown in Figure 10) bent from a single piece of sheet metal. The fins 2, made of non-bent sheet metal, are divided into sections, between which a bent sheet metal section serves as a connecting web 3 to the next fin. In this embodiment, the fins themselves have no beveled surfaces. Gaseous medium can flow between the fins in both the longitudinal direction y and the transverse direction x. The connecting webs 3 form recesses between the fin sections 2, which serve as receptacles for a pipe 7 inserted from above (see Figure 10).

[0064] Figure 2 shows a variant of the slatted structure 1 bent from a single piece of sheet metal. Here, the slats 2 have beveled surfaces 4 on their underside, which can be used, for example, for applying adhesive to connect them to a surface such as a PV module. At the same time, the bevels 4 ensure greater stability of the slatted structure 1. The beveled surfaces and an adjacent area of ​​the slats are provided with slots 5a to minimize thermal stresses caused by different thermal expansion coefficients between the slats and the surface (e.g., the PV module).

[0065] Figure 3 shows a larger section of the lamellar structure 1. Figure 4a shows the sheet 1a of the lamellar structure 1 with slots 5b and 5a before the sheet was bent.

[0066] Figures 4b to 4c show the sheet metal where the bending was performed at successively larger bending angles, thus illustrating the construction of the lamella structure 1 from a single sheet metal. According to the invention, lamella structures 1 with different bending angles are possible, as are partial bends of the lamellae 2, for example, in the central area between the lower support surface and the top around the x-axis. Bending and shaping embossing transverse to this, i.e., around the y-axis, are also possible. This allows the geometry to be optimized, for example, with regard to airflow, depending on the application.

[0067] Figure 5 shows a section of the lamella structure 1 with a shape 2a of the edges of the lamella sections 2, which can accommodate a pipeline with an at least partially circular cross-section. This achieves a positive connection between a pipeline 7 and connecting webs 3. In the figure, the contour 2a at the top is drawn exaggeratedly wide and without radii to clarify the principle. The pipeline 7 is connected to the connecting webs 3 of the lamellae 2 by mechanical pressing. However, other configurations are also conceivable in which the pipeline 7 is connected to the connecting webs 3 of the lamellae 2 by an adhesive, a weld seam, or a solder.

[0068] Figure 6 shows the lamellar structure 1 with connecting webs with circular segment-shaped embossing 3a for receiving a pipe 7 with a circular cross-section with good contact.

[0069] Figure 7 shows a connecting web 3 widened on the sides by wings 6, which are shaped to rest laterally against a pipe 7, thus increasing the contact area. Figure 7a shows a cross-sectional view of the connecting web 3 with wings 6 and a pipe 7. At the bottom and sides, the connecting web 3 rests directly against the pipe 7. The areas not in contact with the pipe are filled with adhesive 8, creating a bonded connection.

[0070] Figure 8 shows a variant of the finned structure 1 of the finned heat exchanger 9, bent from a single piece of sheet metal. Here, the connecting webs 3 are bent so that they converge downwards. This makes the connecting webs 3 wide enough to form a continuous support for the pipe 7. Figure 8 shows bevels 4 on the fins 2 at the bottom. This design is also possible without bevels 4, as shown in Figure 1, or with bevels 4 that cover only part of the area between the fins 2.

[0071] Figure 9 shows a pipe 7 bent from one piece or a pipe meander.

[0072] Figure 10 shows the pipe meander 7, which is inserted into a section of the finned structure 1 and which together form the finned heat exchanger 9.

[0073] Figure 11 shows a flattened cross-section 10 of a pipe meander 7 adapted to a flat connecting web 3.

[0074] Figures 12 and 12a show the connection between the pipe meander and a distribution or collector pipe, for example for applications such as those in the

[0075] EP 3 497 381 B1, once from the outside (Figure 12) and once in section (Figure 12a). Pipeline 7 and distribution / collection pipe 11 consist of an aluminum-plastic composite pipe with an aluminum layer on the outside. A transition piece

[0076] 12 made of plastic is connected by plastic welding to both the end of the pipeline 7 and the distribution-manifold pipe 11. The radial bore

[0077] 13 in the distribution-collector pipe 11 is conical. This reliably protects the cut surface of the outer aluminum layer of the composite pipe from contact with the medium flowing within the distribution-collector pipe 11 and the pipeline 7, and thus from possible corrosion. The same applies to the cut surface of the pipeline 7, which is protected from contact with the medium by the sleeve piece 14 inserted and welded into the pipeline.

[0078] The advantages of the invention are:

[0079] The finned heat exchanger 9 can be produced with significantly fewer manufacturing steps than is usual for round tube finned heat exchangers:

[0080] The fin structure 1, including the defined spacers created by the connecting webs 3, can be manufactured using a continuous process from a single piece of sheet metal, e.g., unrolled from a roll. The complete pipe meander 7 can also be bent from a roll in a continuous process from a single piece, instead of individual U-tubes or channels that must be soldered together. The folded fin structure 1 and the bent pipe meander 7, as well as any surface to be connected to the fin structure, such as a PV module, can be joined together in a single step, e.g., by adhesive bonding. A larger fin spacing than previously possible with round-tube finned heat exchangers ensures, for example, in this application, better air exchange deep into the PV laminate and less material.This, along with the offset fin sections, results in improved heat transfer to the fins for the gaseous medium compared to conventional round-tube or microchannel finned heat exchangers. Using aluminum-plastic composite pipes avoids the Al-Cu material combination commonly found in round-tube finned heat exchangers, thus minimizing corrosion risks and obviating the need for external coating. If the outer shell of the aluminum-plastic composite pipe is made of aluminum, expensive UV stabilization for the plastic is also eliminated. Furthermore, the use of aluminum, which is more expensive and requires higher production energy than plastic, can be minimized. At the same time, corrosion protection on the inside is increased.

[0081] Instead of the described designs, other designs are also possible according to the invention: for example, instead of being connected alternately to the connecting web 3, the slat sections 2 can all be connected on the same side of the connecting web. Instead of the slats being bent 4 on one side, they can also be bent on both sides (top and bottom).

[0082] Instead of the described design with distribution-collector pipe 11 without a plastic layer on the outside, the pipes 7 and / or 11 can also be provided with a plastic layer on the outside, e.g. for corrosion protection.

[0083] The invention relates to a finned heat exchanger 9 for heat transfer between a gaseous medium and a second medium, comprising a pipe 7 for the second medium and fins 2 arranged transversely thereto for increasing the surface area for the gaseous medium, each fin having recesses for receiving the pipe 7, wherein a plurality of fins 2 as a finned structure 1 consist of a continuous sheet 1a which is alternately bent upwards and downwards with horizontal sections in between, wherein the sheet 1a is provided with slots 5b which separate unbent sections of the sheet as vertically or obliquely standing fin sections 2 from bent horizontal sections as connecting webs 3, wherein these horizontal sections form recesses between the fins 2 for receiving a pipe 7,so that, as with round tube finned heat exchangers, there are open spaces between the fins 2 for the gaseous medium in both the transverse direction x and the longitudinal direction y.

[0084] Furthermore, the invention relates to a finned heat exchanger 9 for heat transfer between a gaseous medium and a second medium, comprising a pipe 7 for the second medium and fins 2 arranged transversely thereto for increasing the surface area of ​​the gaseous medium, each fin having recesses for receiving the pipe 7. The pipe 7 consists of an aluminum-plastic composite pipe with plastic on the inside and aluminum on the outside and is bent from a single piece. List of reference symbols

[0085] 1 Lamellar structure

[0086] 1a sheet metal

[0087] 2 slats

[0088] 2a Contour of the slat for holding the pipe

[0089] 3 Connecting web (bent sheet metal section)

[0090] 3a Connecting bar with circular segment embossing

[0091] 4 Edge on slat or support surfaces

[0092] 5a Slot as expansion joint

[0093] 5b Slot in sheet metal to separate differently curved areas (slats 2 and connecting webs 3)

[0094] 6 Lateral widening (“wing”) of the connecting web 3 or the support of the pipeline 7

[0095] 7 Pipeline or pipe meander

[0096] 8 glue

[0097] 9 finned heat exchangers

[0098] 10 flattened cross-section of a pipe meander 7

[0099] 11 Distribution-collector pipe

[0100] 12 Transition piece

[0101] 13 (conical) hole in the distribution manifold

[0102] 14 Sleeve piece of the transition piece 12

[0103] 15 space

[0104] 16 bottom edge

[0105] 17 top edge

[0106] 18 Interruption

[0107] 19 Recess

[0108] 20 first row of slats

[0109] 21 second row of slats

Claims

Patent claims 1 . Fin heat exchanger (9) for heat transfer between a gaseous medium and a second medium, with - a pipeline (7) for the second medium, which extends in a z-direction, - at least one lamellar structure (1) consisting of at least one continuous sheet (1a) which is bent alternately upwards and downwards, - wherein the lamellar structure (1) has a plurality of lamellae (2) arranged transversely to the z-direction and spaced apart from one another in the z-direction by gaps (15) for increasing the surface area for the gaseous medium, - wherein the slats (2) each have a lower edge (16) and an upper edge (17), - wherein the lower edges of the slats (2) lie in a base plane extending in the z-direction and in an x-direction arranged transversely thereto, - wherein the lamellar structure (1) has spaces (15) for the gaseous medium between the lamellae (2), which spaces are open in the x and y directions, - wherein the sheet metal (1a) is provided with slots (5b) which separate the slats (2) from connecting webs (3), and wherein the slats (2) have recesses (19) above the connecting webs (3), characterized in that a plurality of slats (2) consist of a continuous sheet metal (1a) as a slat structure (1), and that the recesses (19) are designed as receptacles for the pipeline (7), and that the pipeline (7) is arranged in the recesses (19) and is connected to the connecting webs (3) with thermal contact.

2. Lamellar heat exchanger (9) according to claim 1, characterized in that the connecting webs are arranged approximately at a middle height between the lower edge (16) and the upper edge (17) of the lamellar structure (1).

3. Fin heat exchanger (9) according to claim 1 or 2, characterized in that the fin structure (1) has at least two parallel fin rows (20, 21), in each of which several fins (2) are arranged one behind the other offset from one another in the z-direction, and - that the lower edges (16) of the slats (2) of a first slat row (20) are offset from one another in the z-direction with a gap between them and the lower edges (16) of the slats (2) of a second slat row (21), the slats (2) of which are each connected via a connecting web (3) to a slat (2) of the first slat row (20) assigned to it, and / or - that the upper edges (17) of the slats (2) of the first slat row (20) and the upper edges (17) of the slats (2) of the second slat row (21), whose slats (2) are each connected via a connecting web (3) to a slat (2) of the first slat row (20) assigned to it, are offset from one another in the z-direction.

4. Fin heat exchanger (9) according to one of claims 1 to 3, characterized in that fins (2) are provided on their upper edge (17) and / or lower edge (16) with bevels (4) which have support surfaces.

5. Fin heat exchanger (9) according to one of claims 1 to 4, characterized in that the edges of the fins (2) adjacent to the interruptions have a shape (2a) which is geometrically adapted to an outer contour region of the pipeline (7) facing it and is designed in particular as a negative form of this outer contour region. tet, and that these edges preferably receive the pipe (7) in such a form-fitting manner that the pipe (7) is in thermal contact with the connecting web (3).

6. Fin heat exchanger (9) according to one of claims 1 to 5, characterized in that the connecting webs (3) have a shape which is geometrically adapted to an outer contour region of the pipeline (7) facing it and is designed in particular as a negative form of this outer contour region, and in that the connecting webs (3) come to rest flatly on the outer contour region of the pipeline (7).

7. Fin heat exchanger (9) according to one of claims 1 to 6, characterized in that the connecting webs (3) are flat and that the pipe (7) has a flattened cross-section which lies flat against the connecting webs (3).

8. Fin heat exchanger (9) according to one of claims 1 to 7, characterized in that the connecting webs (3) have on at least one side a tab-shaped widening (6) which is shaped such that it rests laterally on the pipe (7) and enlarges the contact surface.

9. Fin heat exchanger (9) according to one of claims 1 to 8, characterized in that the pipe (7) is integrally connected to the connecting webs (3) and in particular is glued or welded.

10. Fin heat exchanger (9) for heat transfer between a gaseous medium and a second medium, with a pipe (7) for the second medium and transversely arranged fins (2) spaced apart from one another by intermediate spaces (15), preferably made of aluminum, for increasing the surface area for the gaseous medium, wherein the fins (2) each have recesses for receiving the pipe (7), in particular according to one of claims 1 to 9, characterized in that the pipe (7) consists of an aluminum-plastic composite pipe with plastic on the inside and an aluminum layer on the outside, that the aluminum layer is designed such that it conducts the heat transferred by the fins (2) over the entire pipe circumference and the areas between the fins, and that the pipe (7) is bent from one piece.

11. Fin heat exchanger (9) according to claim 10, characterized in that the aluminum layer of the aluminum-plastic composite pipe has a thickness of 0.2 mm to 0.5 mm.

12. Fin heat exchanger (9) according to claim 10 or 11, characterized in that the pipeline (7) is connected to aluminum fins of a finned structure (1) by a welded connection, in particular an ultrasonic or laser beam connection.

13. Fin heat exchanger (9) according to claim 10 or 11, characterized in that the pipe (7) is connected to aluminum fins of a finned structure (1) by an adhesive connection.

14. Fin heat exchanger (9) according to one of claims 10 to 13, characterized in that the pipe (7) is provided at least at one of the two pipe ends with a transition piece (12) with a sleeve piece (14) made of plastic, which is pushed into the pipe and welded or glued to the pipe end of the pipe (7) by plastic welding, and that this transition piece (12) is tightly connected to a distribution or collector pipe (11) made of plastic or aluminum-plastic composite.

15. Fin heat exchanger (9) according to claim 14, characterized in that the transition piece (12) is provided with a distribution or collector pipe (11) made of plastic or aluminum-plastic composite, which has a radial Hole (13), is tightly connected by being received in the hole (13) and welded or glued by plastic welding.

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