DE102008003975A1 - Heat exchanger fins module, heat exchanger and electric heating module - Google Patents

Abstract

A heat exchanger fin module is proposed, which consists of a metal strip, which defines a first plane in the initial state by its longitudinal direction and width direction and is transformed such that it alternately extends from the first plane to a second plane parallel to the first plane forming a number of fluid-flowable heat-exchanger fins connecting the first and second planes, wherein in the first and second planes substantially planar heat-transfer sections are formed, which line up in the longitudinal direction and at least partially cover the first and second planes , The metal strip is superposed in two layers on a partial surface of the heat transfer sections. The invention further comprises a heat exchanger and an electrical heating module for air flow heating with at least one PTC heating element and at least one adjoining, air-flowable heat dissipation area in which at least one heat exchanger fin module is arranged and is in operative connection with the PTC heating element.

Description

The The invention relates to a heat exchanger fin module according to the preamble of claim 1 and a heat exchanger and an electric heating module for air flow heating, each with such heat exchanger lamella modules.

One Heat exchanger fin module of the present type exists So from a metal strip in the initial state by its longitudinal direction and Width direction defines a first plane and is reshaped that it periodically from the first level to a second, to the first Level parallel plane alternates to a number from the first and the second level connecting fluid-flowable Form heat exchanger fins. The metal band forms substantially planar heat transfer sections in the first and second planes from, which line up in the longitudinal direction and the first and second levels each at least partially, preferably essentially cover up.

Such Heat exchanger lamella modules are used in heat exchangers, such as automotive radiators or heating modules used for air flow heating. They serve to heat from the heat transfer sections into the fluid throughflowable Heat exchanger fins to direct where the heat then delivered to the fluid flowing through, usually air or vice versa. At the heat transfer sections are heating elements (in the case of heating modules for air flow heating), if necessary cooling elements (if that through the slats flowing fluid to be cooled) or in turn fluid durchströmmare Channels (for example in the case of motor vehicle radiators) in heat-conducting contact with the heat transfer sections arranged.

Known heat exchanger lamella modules of this type extend, seen in plan view on their narrow side, ie in the width direction, in rectangular meanders or in sinusoidal or sinusoidal waves, or in a triangular shape, which arises because the metal strip of a heat transfer section in the Starting from the first plane, it is deflected diagonally backwards to the second plane in order to be able to connect there to the preceding heat transfer section. Examples of the described forms of known heat exchanger fin modules can be found in 17 ,

One preferred field of application for heat exchanger lamella modules of the aforementioned type is in electrical heating modules for Air flow heating, especially in vehicles, with PTC heating elements. PTC heating elements are semiconductor resistors made of ceramic, whose ohmic resistance is temperature-dependent. The resistance-temperature characteristic behaves nonlinear: The resistance of a PTC heating element initially decreases slightly with increasing component temperature, then at a characteristic temperature (reference temperature) to rise very steeply. This overall positive course of the resistance-temperature characteristic (PTC = Positive Temperature Coefficient) causes a PTC heating element has self-regulating properties. At a Component temperature, which is significantly lower than the reference temperature is located, the PTC heating element has a low resistance, so that correspondingly high currents are passed through can. If for good heat dissipation is provided by the surface of the PTC heating element is So a lot of electrical power was added and as Given off heat. Increases the temperature of the PTC heating element however, above the reference temperature, the PTC resistance increases rapidly, so the electrical power consumption to a very low Value is limited. The component temperature then approaches an upper limit, which depends on the heat absorption the environment of the PTC heating element. Under normal environmental conditions Thus, the component temperature of the PTC heating element can not over a characteristic highest temperature rise, even if the desired heat dissipation in case of failure completely un interrupted. This and the self-regulating properties of a PTC heating element, due to which the electrical power absorbed corresponds exactly to the thermal output, predestined PTC heating elements for use in heating or air conditioning systems of vehicles or in other applications of air flow heating in vehicles. Because for security reasons may in this application, even in case of failure no flammable Temperatures in the heating element arise, but nevertheless in normal operation a high heating capacity is required.

Electrical heating modules with PTC heating elements and heat exchanger lamella modules of the type mentioned are usually made of several layers of surface next to each other, with its narrow side in the air flow PTC heating elements, which are electrically contacted at their flat tops and bottoms with contact surfaces. Adjacent thereto are heat exchanger lamellar modules as described above, which are also with their narrow side in the air flow and contact on their broadside the contacting surface of the PTC heating elements at regular intervals, namely with their heat transfer sections, thermally overlying. In order to achieve a good heat dissipation from the PTC heating elements to the heat exchanger lamella modules, adhesive connections can be made or other joining techniques are used; However, it has been found to be the most efficient solution to put the PTC heating elements and the heat exchanger lamellae modules in a frame that summarizes this to a heating module and to provide within the frame at least one spring element, the alternately arranged heat exchanger fins modules and the webs with the PTC Heaters pressed together. An example of such a known electric heating module is in EP-A-0 350 528 described.

The just described for electric heating modules spring loaded Pressing the heat exchanger fin modules to the PTC elements or at the contacting surfaces requires a high Stability of the heat exchanger lamella module meandering lamellas; because the Heat transfer from the PTC heating element into the heat exchanger fin modules requires relatively high contact pressures to be efficient. But also in other appli cations, such as in motor vehicle radiators, is a high intrinsic stability of the heat exchanger lamella modules highly desirable.

Of the The present invention is therefore based on the object, a heat exchanger fins module of the type mentioned in terms of its stability and improve efficiency, as well as a heat exchanger and an electric heating module for air flow heating with specify improved heat exchanger lamella modules.

Solved this task is achieved by a heat exchanger lamella module with the features of claim 1, by a heat exchanger with the features of claim 10 and by an electrical Heating module with the features of claim 11.

preferred Embodiments of the heat exchanger fin module according to the invention result from the claims 2 to 9, preferred developments the corresponding electric heating module are in the claims 12 to 14 laid down.

One initially described heat exchanger fins module is according to the present invention thus improved in that the metal strip, which makes up the lamellae module, on a partial surface the heat transfer sections superimposed two layers is, wherein the resulting two-ply face and the remaining single-ply face of the heat transfer sections over extend the entire width of the metal strip and in the longitudinal direction of the metal strip are arranged one behind the other. This means, that the metal strip after the formation of a heat transfer section not proceeding directly from this, forming a lamella to the other Level, but first completely bent over and a second layer of the heat transfer section Forming again runs backwards until it at the rear end of this two-ply face, preferably about halfway along the longitudinal extent of the heat transfer section, is bent down and forming a lamella to the other level crossed over, where it is again bent to the front and the single-layer part of a heat transfer section there forms. The course of the blade is preferably orthogonal to However, this does not have to be the first and second level of the fin module so be and depends in particular on the wanted two-ply overlap the heat transfer sections from.

The partially two-layered design of the heat transfer sections leads to a high stability of the same. simultaneously It is through the inventive design of Slat modules possible for the first time, the heat transfer sections to line up directly adjacent to one another and still Form fins orthogonal to the plane of the heat transfer sections run and thus a force that the first level against the second Level push seeks to provide maximum resistance. simultaneously are the heat exchanger plate modules according to the invention by a purely mechanical (cold) deformation of a metal strip produced. The metal band may be made of any suitable material good heat conduction, z. As aluminum, brass or copper be made.

Under "first "Level" and "second level" are also included The present invention is not always in mathematical levels Meaning to understand. Rather, these "levels" also along a curved surface with a relatively large one Bend radius extend, for example, a circular Arrangement of several heat exchanger lamella modules instead to allow a strictly row-like arrangement.

The Inherent stability of the lamella module according to the invention can be improved even if in one of the two-ply Partial faces facing away from the rear transverse edge of the single-layered Part surface of each heat transfer section a recess for receiving one of the single-layer partial surface facing away from the front edge of the two-ply part of the next molded adjacent heat transfer section is, so that adjacent heat transfer sections can overlap in the longitudinal direction so far.

Such a development of the lamella module according to the invention can thus be optimized are when the leading edges of the two-ply faces are pressed against the recesses of the rear transverse edges of the single-ply faces, in such a way that the contact pressure is fluid-tight. This fluid-tightness makes it possible for the lamella module in particular to be able to flow through liquids without these being able to escape laterally from the lamella module. The lamella module thus forms fluid-tight channels between the individual lamellae.

Preferably is the heat exchanger plate module according to the invention formed by a metal band, which is reshaped so that it for forming a first heat transfer section in the first plane extends longitudinally forward, then crimped at a first leading edge to the second plane is and, lying on the heat transfer section, forming a two-ply face of the same, returned is until it comes out of the first level and one forming the first section of lamella extending towards the second plane is bent, and then in the second plane again in the longitudinal direction bent forwards to a second heat transfer section to form in the second level, where it is then at a second leading edge is flanged to the first level and, on the second heat transfer section lying on, forming a two-ply part of the same, is traced back to it from the second level leading out and forming a second sipe section bent back to the first level, etc. Accordingly uncomplicated is the machine production of the invention Slat module made of a commercially available metal strip.

A Another preferred embodiment of the invention is that in the heat exchanger fins substantially transversely and / or directed substantially along the fluid flow Beading are molded to better swirl through the To cause slats through flowing fluid. Such Whirling in the lamella area increases the heat transfer from the fins into the fluid (and vice versa).

To the same purpose, the heat exchanger fins also with substantially transverse to the fluid flow Be provided Ausbrechungen. These can be especially easy be introduced into the slats.

The Heat exchanger fins of the invention Finally, lamella modules can be used with fluid flow-conducting Be provided bends to the leading through the slats fluid flow distract.

One Heat exchanger fin module according to the present invention can be used in all types of heat exchangers. However, a particularly preferred application is in electrical heating modules for air flow heating, the at least one PTC heating element and at least one adjoining, air-permeable Heat release area include. In this heat release area is then at least one heat exchanger fin module according to the invention arranged, which is in operative connection with the PTC heating element and the heat from this in through the lamella module discharges sweeping airflow.

One very good heat transfer from the PTC heating element in the heat exchanger fins module and there naturally in the heat transfer sections is due to the Peculiarity of the PTC heating element of particular importance; because this then absorbs a lot of electrical power and sets them to heat when kept at a low temperature The heat generated is thus fast and complete is derived. The heat transfer between the PTC heating element and a lamella module is then according to experience best if the lamella module to the surface of the PTC heating element is pressed. The extraordinarily high Inherent stability of the invention Heat exchanger fins module is therefore just in this Scope of application of great advantage.

There PTC heating elements usually formed plate-shaped are an electric heating module is expediently designed so that in each case at least one PTC heating element between two heat exchanger plate modules according to the invention is arranged, which with their heat transfer sections rest directly or indirectly on the PTC heating element. Thus, will On the one hand, the heat generated in the PTC heating element on both sides dissipated in the airflow, which reduces the efficiency of the heating module increased, and on the other hand, the PTC heating element then completely simply via the two heat exchanger lamella modules be contacted electrically.

Between the PTC heating element and the heat exchanger lamella modules can each be arranged a metallic contact element. This then serves not only for electrical contact, but also for a mechanical pressure distribution to load peaks on the PTC heating element to avoid. As far as the PTC heating elements themselves not over the entire area of the heat transfer sections the lamella modules extend, but smaller in comparison are designed to ensure such intermediate metallic contact elements also a more even heat distribution in the lamella modules.

A further advantageous embodiment of an inventive Finally, the electric heating module is that the PTC heating element not as a plate-like structure, but is designed as a fluid-flowable tube. In this case, the PTC heating element then can not only air flow by means of the heat exchanger lamella modules, but also a flowing through the PTC heating element further fluid flow, in particular liquid flow. at Need can from such an electric heating module even a cooling unit for transmitted air, and then if that PTC heating element off and a cooling fluid through this is passed through.

Several Exemplary embodiments of heat exchanger lamella modules according to the present invention are illustrated in the drawings and described and explained in more detail below. Show it:

1 a side view of a first embodiment of a heat exchanger fin module according to the invention;

2 a perspective view of the lamella module 1 ;

3 a side view of a second embodiment of a heat exchanger fin module according to the invention;

4 a perspective view of the lamella module 3 ;

5 a side view of a third embodiment of a heat exchanger fin module according to the invention;

6 a perspective view of the lamella module 5 ;

7 a side view of a fourth embodiment of a heat exchanger fin module according to the invention;

8th a perspective view of the lamella module 7 ;

9 a side view of a fifth embodiment of a heat exchanger fin module according to the invention;

10 a perspective view of the lamella module 9 ;

11 a perspective view of lamellae modules 2 in heat exchanger arrangement;

12 a perspective view like 11 but a kit for an electric heating module;

13 a representation like 12 but a modified embodiment;

14 a perspective view of an electric heating module as 13 but in assembled condition;

15 a perspective view of a section of a heat exchanger according to the present invention;

16 a representation like 12 but a still modified embodiment;

17 Examples of prior art heat exchanger fin modules.

In the 1 and 2 an embodiment of a heat exchanger fin module is shown in side view and perspective view, which exemplifies the present invention. How special 1 As can be seen, the lamellar module is made of a metal strip which alternates between a first plane A and a second plane B and thereby in the first plane A heat transfer sections 2a and in the second level B heat transfer sections 2 B forms, while the connectors between the planes A and B vertical heat exchanger fins 3 form. The metal strip here has been reshaped to form a first heat transfer section 2a in the first plane A, then at a first leading edge 4a crimped to the second level B and on the heat transfer section 2a overlying, a two-ply partial surface 5a forming, was returned against a longitudinal direction x, until it out of the first plane A leading out and a first fin section 3a has been bent to the second plane B, and then in the second plane B in the longitudinal direction x to the front - in the illustration so to the right - is bent away, to a second heat transfer section 2 B to form B in the second level. There, the metal band is again at a second leading edge 4b crimped to plane A and, on the heat transfer section 2 B overlying, a two-ply partial surface 5b forming, until it leads out of the second plane B and a second fin section 3b forming bent to the first plane A, etc., The leading edges 4a . 4b the heat transfer sections 2a . 2 B lie in each case at the rear transverse edges 6a . 6b the respective adjacent heat transfer sections, so that essentially how 2 illustrates a closed area lined up heat transfer sections 2a . 2 B formed. Because the heat exchanger fins 3a . 3b in the present embodiment, orthogonal to the planes A and B and the just mentioned, substantially closed design of the heat transfer sections 2a respectively. 2 B desired, results from geometric necessities that the heat transfer sections 2a and 2 B each half about two layers and formed on the other half of a single layer. The resulting stability of the illustrated heat exchanger fin module, in particular in a direction perpendicular to the planes A and B direction, is evident.

In the 3 and 4 another embodiment is shown, wherein the representations of the representations of 1 and 2 correspond. The difference of this embodiment of an inventively designed heat exchanger fin module to that shown in the previous figures is that the heat transfer sections 2a . 2 B no longer just strung together, but slightly overlapping. The single-layer partial surfaces of the heat transfer sections 2a . 2 B are each with a recess 7a . 7b provided, the leading edge 4a . 4b the next adjacent heat transfer section 2a . 2 B adjusted so that this one piece far into the single-ply face of the heat transfer section 2a . 2 B can extend and the heat transfer sections 2a . 2 B nevertheless form a substantially flat surface. Accordingly, in this embodiment, the two-layered partial area and the single-layered partial area of each heat transferring section are not equal in size, since the heat-exchanging fins 3a . 3b here again perpendicular to the levels A and B stand.

The leading edges 4a . 4b the heat transfer sections 2a . 2 B This embodiment are so in the recesses 7a . 7b pressed, that results in a fluid-tight connection. The spaces between the heat exchanger fins 3a . 3b thus form fluid-tight channels. In addition to the again significantly increased stability of this example of an inventive heat exchanger lamella module so it is also universally applicable due to the fluid tightness, although the production of the module is hardly more expensive than in the previous embodiments.

The in the 5 and 6 . 7 and 8th such as 9 and 10 In each case illustrated embodiments represent variations those embodiments of a lamella module according to the invention, which in the 1 and 2 is shown. The heat exchanger fins 3 in the 5 and 6 illustrated embodiment are with vertical beads 8th provided while the heat exchanger fins 3 in the 7 and 8th illustrated Ausfüh approximately example alternately introduced from above and below Ausbrechungen 9 exhibit. Both the beads 8th as well as the break-outs 9 cause a fluid to flow between the heat exchanger fins 3 flows through, in the spaces between the slats 3 more swirled and thus more efficient heat from the slats 3 receives or gives to this.

The heat exchanger fins 3 in the 9 and 10 illustrated embodiment of a fin module according to the invention are seen in the flow direction approximately centrally starting with bends 10 provided, which are shaped pocket-like and between the slats 3 Through deflecting fluid flow laterally. In addition to a deliberate deflection of the fluid flow, this measure also increases the efficiency of the heat transfer from the fins 3 on the fluid flowing through.

11 shows an example of a heat exchanger assembly of two heat exchanger fin modules of the type as shown in the 1 and 2 is shown. A first heat exchanger lamella module 11 and a second heat exchanger fin module 12 are arranged one above the other so that between the lower heat transfer sections 2a of the upper lamella module 11 and the heat transfer sections 2 B of the lower lamella module 12 a space remains, through which another fluid can be passed, or in which a heating element can be used.

The latter alternative is in the embodiment shown in FIG 12 is shown as a schematic exploded view realized. Between the upper heat exchanger fin module 11 and the lower heat exchanger fin module 12 becomes a PTC heating element 13 used, which in the assembled state, the heat transfer sections 2a . 2 B the two lamella modules 11 . 12 contacted, receives from this stream and gives off to this heat.

13 shows a variation of this construction: Here is provided between the heat transfer sections 2a . 2 B the two lamella modules 11 . 12 and the PTC heating element 13 in each case a plate-shaped metallic Kontaktele element 14 . 15 which ultimately leads to the in 14 shown construction of an electric heating module leads.

15 shows a portion of a heat exchanger with three inventively constructed heat exchanger fin modules 11 . 12 . 16 , These lamellar modules are constructed as in the 2 and 3 shown and therefore have a special this high inherent stability. Between them, each directly on the heat transfer sections 2a . 2 B lying, there are pipes 17 for the passage of liquids. The heat exchanger section shown here is therefore for heat transfer from a through the pipes 17 flowing liquid on through the lamellar modules 11 . 12 . 16 flowing fluid, usually air, and could be used for example in a motor vehicle radiator or in a heater fan.

The in 15 The structure shown can be used identically as an electric heating module when the pipes 17 made of PTC ceramic material. It then only has to be provided an electrical contact, in the simplest case as in the previous embodiments of the lamella modules 11 . 12 . 16 can be done. Such a construction with a pipe 17 made of PTC ceramic material in a schematic exploded view as in 12 is in 16 shown. The heat exchanger lamella modules 11 and 12 are those who are already using the 3 and 4 have been described. Between them is a pipe 17 made of PTC ceramic material, which can thus function both as a heating element and as a cooling element. The electrical contact of the tube 17 takes place via contacting surfaces 18 placed on the top (shown) and the bottom (not visible) of the pipe 17 are arranged and at the lower heat transfer sections 2a of the upper heat exchanger fin module 11 or the upper heat transfer sections 2 B of the lower heat exchanger fin module 12 rest. The electrical contacting of the PTC tube 17 takes place via the heat exchanger lamella modules 11 . 12 ; separate electrical contacting elements are therefore not necessary.

17 schematically shows three examples of lamination modules according to the prior art. The first lamella module is formed in rectangular meanders, whereby both the stability and the total area of the heat transfer sections are not optimal. The second lamella module has a triangular shape of the individual lamellae, which indeed optimizes the coverage of the planes A and B by the heat transfer sections, but is able to be improved in terms of its own stability. Finally, the third lamella module has s-shaped or sinusoidally shaped lamellae, which in turn is detrimental to the intrinsic stability.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• - EP 0350528 A [0006]

Claims (14)

Heat exchanger lamella module consisting of a metal strip ( 1 ) defined in the initial state by its longitudinal direction (x) and width direction (y), a first plane (A) and is so transformed that from the first plane (A) to a second plane parallel to the first plane (A) ( B) alternately extends to a number of the first (A) and the second level (B) connecting, fluid-flowable heat exchanger fins ( 3 ), wherein in the first (A) and the second plane (B) substantially flat heat transfer sections ( 2 ), which line up in the longitudinal direction (x) and respectively at least partially cover the first (A) and second plane (B), characterized in that the metal strip ( 1 ) on a partial surface of the heat transfer sections ( 2 ) is laid over one another in two layers, wherein the two-layer partial area and the remaining single-layer partial area of the heat transfer sections ( 2 ) over the entire width of the metal strip ( 1 ) and in the longitudinal direction (x) of the metal strip ( 1 ) are arranged one behind the other. Heat exchanger lamella module according to claim 1, characterized in that the heat transfer sections ( 2 ) are formed in two layers about half. Heat exchanger lamella module according to one of claims 1 or 2, characterized in that in a side facing away from the two-ply face rear transverse edge ( 6 ) of the single-ply face of each heat transfer section ( 2 ) a recess ( 7 ) for receiving a front edge facing away from the single-layer partial surface ( 4 ) of the two-ply part surface of the next adjacent heat transfer section ( 2 ) is formed so that adjacent heat transfer sections ( 2 ) in the longitudinal direction (x) overlap. Heat exchanger lamella module according to claim 3, characterized in that the leading edges ( 4 ) of the two-ply faces of the heat transfer sections ( 2 ) substantially fluid-tight to the recesses ( 7 ) of the rear transverse edge ( 6 ) of the single-layer partial surfaces of respectively adjacent heat transfer sections ( 2 ) are pressed. Heat exchanger lamellar module according to at least one of claims 1 to 4, characterized in that the metal strip ( 1 ) is converted so that it is for forming a first heat transfer section ( 2a ) in the first plane (A) in the longitudinal direction (x) forward, then at a first leading edge ( 4a ) is crimped to the second level (B) and, on the heat transfer section ( 2a ), forming a two-layer partial surface of the same, is led back until it leads out of the first plane (A) and a first heat exchanger lamella ( 3a ) is bent to the second plane (B), and then in the second plane (B) in turn in the longitudinal direction (x) is bent forward to a second heat transfer section ( 2 B ) in the second plane (B), where it then at a second leading edge ( 4b ) is flanged towards the first plane (A) and, on the heat transfer section ( 2 B ) lying on a two-ply part of the same surface, is guided back until it leads out of the second plane (B) and a two te heat exchanger blade ( 3b ) forming the first plane (A) is bent down, etc. Heat exchanger lamella module according to at least one of claims 1 to 5, characterized in that the heat exchanger fins ( 3 ) are substantially orthogonal to the first and second planes (A, B). Heat exchanger lamellar module according to at least one of claims 1 to 6, characterized in that in the heat exchanger fins ( 3 ) substantially transversely and / or substantially longitudinally directed to the fluid flow beads ( 8th ) are formed. Heat exchanger lamellar module according to at least one of claims 1 to 7, characterized in that the heat exchanger fins ( 3 ) with breaks directed essentially transversely to the fluid flow ( 9 ) are provided. Heat exchanger lamella module according to at least one of claims 1 to 8, characterized in that the heat exchanger fins ( 3 ) with fluid flow-conducting bends ( 10 ) are provided. Heat exchanger with heat exchanger lamella modules according to one of claims 1 to 9. Electric heating module for air flow heating, comprising at least one PTC heating element ( 13 ) and at least one adjoining, air-flowable heat dissipation area, in which at least one heat exchanger fin module ( 11 . 12 . 16 ) is arranged according to one of claims 1 to 9 and with the PTC heating element ( 13 ) is in operative connection. Electric heating module according to claim 11, characterized in that at least one PTC heating element ( 13 ) between two heat exchanger lamella modules ( 11 . 12 ) is arranged and these with their heat transfer sections ( 2a . 2 B ) directly or indirectly on the PTC heating element ( 13 ) rest. Electric heating module according to claim 12, characterized in that between the PTC heating element ( 13 ) and the heat exchanger lamella modules ( 11 . 12 ) each have a metallic contact element ( 14 . 15 ) is arranged. Electric heating module according to at least one of claims 11 to 13, characterized in that the PTC heating element ( 13 ) as a fluid-flowable tube ( 17 ) is trained.