DE3728303A1 - HEAT EXCHANGER WITH A RIB TUBE ARRANGEMENT - Google Patents

Description

The invention relates to a heat exchanger according to the preamble of claim 1. Such a heat exchanger is from the DE-PS 35 32 493 known. With this design, one becomes art fabric-made tube sheet in a particularly simple manner Connected metal pipes. That happens there because the free ends of the tubes, each in a known manner to a Ribbed tube block are grouped in grooves by holding approaches of the tube sheets. The so in the Tube ends are then in the Sealed tube sheet that after pressing in the tube ends with a widening mandrel both the plastic of the holding piece, and the end of the tube is expanded radially. Such Types are known because of the use of metallic Rib tube block bound to certain design specifications.

It is also known to form heat exchangers by positive engagement to assemble individual components from plastic (EP-OS 01 91 956). To build such a heat exchanger used plastic parts are extruded. Such designs are not for everyone due to the lack of finned tube arrangement Purposes. The necessary wall thicknesses of such extru dated plastic components are also relatively high, so that Heat exchange capacity is affected.

Finally, it is also known (DE-OS 35 36 527), one Heat exchanger block for a liquid / air / heat exchanger from a one-piece injection molded part, in particular from aluminum produce, the tubes of which are each wedge-shaped up to Narrow the center so that the cores necessary for the casting are re-formed can be removed during manufacture. Even those on both Sides of one piece cast-on tube sheets must be  Removing the core can be designed appropriately. Except that a narrowing of the flow cross section in the pipes is unfavorable, it is with such a manufacturer Only possible, certain, given by the form To manufacture heat exchanger types. A way to There is no variation in the finned tube block shape or size.

The invention has for its object a heat exchanger with a finned tube arrangement, in particular a water / air cooler for motor vehicles made of plastic so that there is largely freedom for the construction of the heat exchanger, so that both in the form, as well as in the Performance of different heat exchangers with the same components are producible.

To solve this problem with a heat exchanger the characterizing features of the patent Claim 1 provided. In contrast to the well-known construction types where the tube sheets are already in die casting or injection molding are partially connected to the finned tube block is invented According to the invention, only either a tube equipped with fins or a group of tubes that have common fins as uses a module component, which is then connected to a tube sheet is connected to the final shape in the desired manner. Here can the ends of the pipes or the pipe groups in relative simple and well-known way with the associated tube sheet be connected as both the pipes or pipe groups finally, their ribs arranged in one piece, as also the tube sheet are made of plastic. Known verb types of application, such as friction or laser welding, Ultrasonic welding, but also gluing or mechanical joining can therefore be used to assemble tube sheets and modular components be used. The advantage of laser welding achieved that different materials can be welded are.

Since the pipes with the associated ribs made of plastic after  the injection molding process, do not need a cone shaped extensions of the pipes to be provided to the To be able to remove cores. The new modular components therefore have an even flow cross-section for heat exchange media on.

Advantageous developments of the inventive concept are in marked the subclaims. The features show of subclaims 2 to 5 have the advantage that despite the Use of a positive connection when pressing in the pipe ends no constrictions in the area of the openings of the tube sheets either or expansion of the flow cross-section must occur.

A uniform flow through the finned tube arrangement is therefore possible.

The features of subclaims 6 and 7 have the advantage that through the flange a relatively large, for example for suitable contact surface on the tube sheet is available stands. The raised edge stiffens the Module component reached.

The features of subclaims 8 to 10 have the advantage that the individual module components, especially individual ones Tubes with the outer edges of their ribs to different construction forms of the entire heat exchanger block can be combined can, without being adjacent between the aligned ribs Module components the gaps influencing the flow occur.

The features of subclaims 11 to 13 offer the advantage that the air flowing through stimulates increased turbulence is, which improves the heat transfer. The characteristics of subclaims 14 to 17 outline different possibilities due to cross-sectional influences in the pipes that can be specially designed as flat tubes, even the  Turbulence and heat transfer from the liquid to the To improve pipe walls.

The invention is in the drawing based on execution examples and is explained in the following. It demonstrate:

Fig. 1 shows a schematic longitudinal section of an invention by a part, at least one module component, and with two associated tube sheets constructed with radiator tanks of plastic heat exchanger,

Fig. 2 shows the section through the heat exchanger of FIG. 1 along the line II-II,

Fig. 3 shows a heat exchanger similar to FIG. 1, but in which used to produce the same size as in Fig. 1, a plurality and other module components,

Fig. 4 is a section through the heat exchanger of FIG. 3 along the line IV-IV,

Fig. 5 is an enlarged detail view of the connection area between tube end and tube plate, as may be seen in one of the heat exchanger of FIGS. 1 and 3 before,

Fig. 6 shows another connection possibility in a Dar position similar to FIG. 5,

Fig. 7 similarly shows the schematic representation of a partial section Fig. 4, but in an embodiment wherein the ribs of the associated tube having six corner shape,

Fig. 8 is a view similar to FIG. 7, but with a module component in which the ribs have trapezoidal shape,

Fig. 9 is a view similar to Figs. 7 and 8, but using flat tubes surrounded by ribs with a trapezoidal shape, wherein several, each made up of a tube modular components with the outer edges of their ribs combined to form a multi-row finned tube heat exchanger are,

, However, the individual modular components are assembled to form an annular heat exchanger Fig. 10 is a view similar to FIG. 9 in which,

Fig. 11 is a section through another embodiment of a modular component with a flat tube and having a rectangular rib arrangement, wherein the internal cross section of the flat tube is designed in a special way,

But slightly enlarges Fig. 12 is a sectional view similar to FIG. 11 ver and in one embodiment in which the internal cross-section is configured differently,

Fig. 13 is a sectional view similar to FIG. 11 with a flat tube which is constructed of a multi-chamber cross section,

Fig. 14 is a partial section similar to FIG. 6, but at a modular component with ribs in corrugated shape,

Fig. 15 shows the view of the module component of FIG. 14 in the direction of arrow XV,

Fig. 16 shows the enlarged representation of a partial section are provided by a rib of Fig. 14, wherein the turbulence generating the tips of the ribs and

Fig. 17 is a schematic representation of an embodiment in which the tubes of the heat exchanger are composed of several pipe sections.

In Figs. 1 and 2, a part is shown of a heat exchanger made of plastic ago, which consists of a single piece made of plastic modular component (10) and of the two, in each case with the ends of the tubes (1 '), this module component (10) connectable tubesheets ( 2 ) with water boxes ( 4 ) and ( 5 ) be. Tube plates ( 2 ) and water boxes ( 4 ) and ( 5 ) are also made of plastic in the embodiment.

The module component ( 10 ) of FIGS. 1 and 2 consists of 25 individual tubes ( 1 '), which were arranged in columns and rows each with the same distance from each other and by common, perpendicular to the tube axes ( 1 a ) extending lamellar other ribs ( 6 ') arranged in the form of square plates are firmly connected. Pipes ( 1 ') and fins ( 6 ') form a single component, molded or molded from plastic. The ends ( 9 ) of the tubes ( 1 ') protrude from this component and are connected to the tube sheets ( 2 ) in a manner yet to be explained (see, for example, FIG. 5). In the embodiment of FIGS. 1 and 3, the upper tube sheet ( 2 ) is part of an integrally connected water box ( 4 ). The lower tube sheet ( 2 ) is separate from the water box ( 5 ), which is ver bindable in a known manner with the tube sheet ( 2 ). As Fig. 2 shows, a further module component can (10 A) or other module components of the same type as the module component (10) are connected to this module component (10), wherein the compound of modular components (10, 10 A) with each other each has a common tube sheet ( 2 ) which is formed from the desired final shape of the heat exchanger.

FIGS. 3 and 4 show a modification of the heat exchanger of Fig. 1 and 2 in that there is here as the module component (1) only consists of a tube (1) having integrally disposed thereon ribs (6). As shown in FIG. 4, these individual modular construction parts ( 1 ), ie the tubes ( 1 ) with the associated ribs ( 6 ), are put together to form a heat exchanger block similar to FIG. 2 in that the outer edges of the ribs ( 6 ) are arranged abutting one another and the individual tubes ( 1 ) are received with their ends in common tube sheets ( 2 ).

Fig. 5 shows a first possibility of joining a tube plate (2) with the ends (9) of the tubes (1) of the execution form of the Fig. 3 and 4. In this embodiment, the tube ends (9) extended and have a diameter ( d _E ), which is larger than the inner diameter ( d ) of the tube ( 1 ) itself. These extended tube ends ( 9 ) are pressed into a circumferential slot ( 11 ) in an edge ( 8 ) of the tube sheet ( 2 ), which formed like a sleeve and is provided in the region of the opening ( 7 ) of the tube sheet ( 2 ) for the tube ( 1 ). The design is carried out so that the width of the insertion groove ( 11 ) speaks to the thickness of the wall of the tube end ( 9 ) ent and that the depth ( h ) of the insertion groove ( 11 ) the length ( 1 ) of the expanded area of the tube end ( 9 ) is adjusted. It is also ensured that the distance between the opening ( 7 ) facing the wall of the plug-in groove ( 11 ) and the inner wall of the opening ( 7 ), which has the diameter ( D _R ), the difference of the diameter ( d _E -d ) corresponds. In such an embodiment, there will be no change in diameter inside the tube ( 1 ) after the tube end ( 9 ) has been pushed into the plug-in groove ( 11 ) until the stop, because the enlarged area of the tube end ( 9 ) from the sleeve-like inner part ( 30 ) of the edge ( 8 ) is filled. Since both the tube sheet ( 2 ) including the rim ( 8 ), and the tube ( 1 ) with the ribs ( 6 ) arranged in one piece thereon are made of plastic, this form-fitting joining can result in a very tight connection between the tube sheet ( 2 ) and the tube ( 1 ) can be achieved.

Of course, it is also possible to bind additional adhesive for sealing and sealing between the tube sheet ( 2 ) and tube ( 1 ) before, if this should be necessary. Tight connections can also be achieved by ultrasonic or laser welding, the plug-in groove ( 11 ) only having to be designed for preassembly.

Another type of connection between the tube sheet ( 2 ) and tube ( 1 ) is shown in Fig. 6. Here, the pipe ends ( 9 ) have an outwardly projecting flange ( 12 ) which extends perpendicular to the pipe axis ( 1 a ) and is provided with a circumferential rib ( 13 ) which projects in the direction of the pipe axis ( 1 a ). The tube bottom ( 2 ) is provided in the region of the opening ( 7 ) with an edge ( 8 ') which has a counter surface ( 31 ) which runs parallel to the surface ( 32 ) of the flange ( 12 ) and which can be used for this Assemble the tube ( 1 ) with the help of the flange ( 12 ) with an adhesive connection to the tube sheet ( 2 ).

It would also be possible to make the connection using ultrasound or a laser. In the embodiment shown, the tightness of the connec tion is additionally increased by the rib ( 13 ); the rib ( 13 ) also has the advantage of stiffening the pipe end ( 9 ) and stiffening the heat exchanger.

In Figs. 7 to 10 are shown possibilities to shape the outer contour of the ribs (6) of a modular component consisting shown from a tube or a flat tube, unlike in Fig. 4. In FIG. 7, the shape of a hexagon (14) is shown for the outer contour of the ribs (6) of the module component (1).

These ribs can therefore be aligned with their outer edges ( 34 ) and ( 35 ) on adjacent hexagonal rib contours ( 14 A ) and ( 14 B ). The honeycomb shape of the fins ( 6 ) allows largely any type of heat exchanger to be manufactured.

This also applies if the ribs ( 6 ) of the modular component ( 1 ) have the shape of a trapezoid ( 15 ) which, as shown in FIG. 8, forms a series of with other adjacent ribs in a trapezoidal shape ( 15 E ) Pipes can be put together, which can of course be combined with other rows to form a finned tube block, which is held together by appropriate tube sheets.

FIGS. 9 and 10, finally, show the possibility, instead of tubes (1) having a circular cross section flat tubes (1 ') with about an oval cross section to be used which also may be surrounded by ribs having a trapezoidal shape (15). Here too, two or more rows of heat exchanger blocks can be built, for example by joining adjacent trapezoidal shapes ( 15 A and 15 B ). As shown in Fig. 10, it is also possible to build circular heat exchangers with the trapezoidal shape ( 15 ) and the correspondingly created trapezoidal shapes ( 15 C ) and ( 15 D ) of the fins of flat tubes ( 1 '). Of course, it is also possible to provide the hexagonal outer contour or the trapezoidal outer contour, as well as, for example, a uniform octagonal contour of the ribs, not only in the case of a modular component which is each constructed from a tube. Of course, the common fins ( 6 ') of FIG. 2 in a modular component ( 1 '), consisting of several individual tubes, can be brought into such polygonal shapes that can then be combined with one another to form larger heat exchanger blocks. The invention therefore makes it possible to manufacture heat exchangers of various shapes and capacities from uniform plastic module components. The arrangement of the fins connected in one piece to the tubes also allows the wall thickness of the tubes themselves to be chosen to be relatively small without affecting the strength. This has an advantageous effect on the heat transfer. The new modular components are preferably suitable for the construction of heat exchangers, such as those used in stationary and transient heating technology. By choosing a suitable plastic, such heat exchanger systems can also be used with corrosive and / or aggressive media.

To improve the heat transfer while maintaining stability, flat tube shapes according to FIGS . 11 to 13 can also be provided. Fig. 11 shows an embodiment in which a flat tube ( 1 ') with approximately rectangular ausgebil Deten ribs ( 6 ) is provided. However, this flat tube has an internal cross section that has no parallel side walls ( 22 ) and ( 23 ). Rather, these inner walls ( 22 and 23 ) are provided with ribs ( 24 ) extending parallel to the direction of flow and increasing the surface area, through which the heat transfer can be improved. The cross-sectional shape of the flat tube ( 1 ') of FIG. 12 has a similar effect, where the inner walls are designed in the form of two interlocking longitudinal teeth ( 25 ) and ( 26 ) which have a zigzag slot ( 27 ) leave. Such cross-sectional shapes of tubes for heat exchangers, which can be equipped with outer fins at the same time, can be produced when using plastic as the production material. The cross-sectional shape of the flat tube ( 1 ') of FIG. 13, which runs parallel to one another, is also particularly stable Chambers ( 21 ) is provided. The plastic used for production can also be stiffened in a manner known per se by fillers and also improved in terms of its heat transfer. A further improvement in the thermal efficiency can be achieved by coating the surface with highly thermally conductive substances, in particular metals, for example copper. The coating also serves as a diffusion barrier for media that can diffuse through plastic and can contribute to increasing the strength. The coating is preferably applied after the assembly of all the module components.

Figs. 14 to 16 show an embodiment of the module of FIG. 3, in which is fitted a pipe (1) with ribs (6), having the waveform. The course of the waves, ie the wave crests ( 18 ) which run parallel to one another, is in each case laid such that the crests ( 19 ) of the wave crests are each perpendicular to the flow direction ( 16 ) in which the air between the ribs ( 6 ) is carried out . In the case of a water / air cooler, the water flows through the pipes ( 1 ) in the direction ( 28 ) or in the opposite direction, as indicated in FIG. 14. The ribs ( 6 ) provided in this way with profiles ( 17 ) force the air flowing through to increased turbulence and thus to an improved heat absorption by the ribs, which in turn pass on the heat given off by the water to the pipes ( 1 ).

Fig. 16 shows a way of designing the wave form, which can be realized in the manufacture of plastic. Here, at the apex ( 19 ) of the wave crests ( 18 ) on one side of the ribs ( 6 ), inclined edges ( 20 ) against the flow direction ( 16 ) are provided, which help to promote the breaking off of the flow and the increase in turbulence. As can be seen from FIGS . 14 and 15 without further ado, the formation of the modular component of those figures is made possible by pulling out a cylindrical core from the tube ( 1 ) and by pulling off the mold halves in the direction of the wave crests. Since plastic is used as the production material, it is not absolutely necessary to provide conical core parts for the pipes. The plastic is still elastic during demolding and therefore also allows the demolding of cylindrical cores.

Fig. 17 shows a possibility to assemble the pipes ( 1 ) themselves from several, in the embodiment of two partial pipe sections ( 1 a , 1 b ). Here are the upper ends of the partial pipe sections ( 1 a ) in the tube sheet of a water tank ( 4 ') and the lower ends in a coupling piece ( 3 ). In the coupling piece ( 3 ) sit sealed the upper ends of the pipe sections ( 1 b ), which open into the second water tank ( 5 '). This structure makes it possible to realize heat exchangers with large pipe lengths.

Claims (19)

1. Heat exchanger consisting of a finned tube arrangement, the tubes ( 1 ) on both sides in the tube sheet ( 2 ) of a water tank ( 4 , 5 ) and the fins ( 6 , 6 ') transverse to the axis ( 1 a) of the tubes ( 1 , 1 ′) of air or the like. are flowed, whereby at least the tube sheet consists of plastic, characterized in that a tube ( 1 ) or a group ( 10 ) of tubes ( 1 ') with the surrounding ribs ( 6 , 6 ') in one piece as a module part made of plastic is formed, which can optionally be assembled with further module components ( 1 A , 1 B , 10 A ) and the tube sheet ( 2 ). 2. Heat exchanger according to claim 1, characterized in that the openings ( 7 ) of the tube sheets ( 2 ) for the tube ends ( 9 ) are provided with sleeve-like edges ( 8 ). 3. Heat exchanger according to claims 1 and 2, characterized in that the edges ( 8 ) of the openings ( 7 ) on their pipe ends ( 9 ) facing the end face are provided with a circumferential plug-in groove ( 11 ) for the pipe ends. 4. Heat exchanger according to claim 3, characterized in that the pipe ends ( 9 ) have a larger diameter than the remaining pipe diameter ( d ) ( d _E ) and that the inner diameter ( D _R ) of the edges ( 8 , 30 ) of the opening ( 7 ) corresponds to the inside diameter ( d ) of the tubes ( 1 ). 5. Heat exchanger according to claim 4, characterized in that the depth ( h ) of the plug-in groove ( 11 ) corresponds to the length ( 1 ) of the wider area of the pipe end ( 9 ). 6. Heat exchanger according to claim 1, characterized in that at the pipe ends ( 9 ) an outwardly perpendicular to the pipe axis ( 1 a ) extending flange ( 12 ) is provided. 7. Heat exchanger according to claim 6 and 3, characterized in that the flange ( 12 ) on its tube plate ( 2 ) pointing side is provided with a circumferential rib ( 13 ) which can be inserted into an insertion groove ( 11 '). 8. Heat exchanger according to claim 1, characterized in that the ribs of the module component ( 1 , 10 ) are all the same out and in a plan view in the direction of the tube axes ( 1 a ) have a polygonal, suitable for assembling adjacent module components. 9. Heat exchanger according to claim 8, characterized in that the ribs ( 6 ) have the shape of a regular hexagon ( 14 ). 10. Heat exchanger according to claim 8, characterized in that the ribs ( 6 ) have a trapezoidal shape ( 15 ). 11. Heat exchanger according to claim 8, characterized in that the ribs ( 6 ) transversely to the inflow direction ( 16 ) with Profilie stanchions ( 17 ) are provided. 12. Heat exchanger according to claim 11, characterized in that a waveform is provided as the profile ( 17 ). 13. Heat exchanger according to claims 11 and 12, characterized in that the turbulence-increasing sharp edges ( 20 ) are provided on at least one side at the apex ( 18 ) of the wave crests ( 19 ). 14. Heat exchanger according to claim 1 and one of the other claims, characterized in that the tubes are designed as flat tubes ( 1 '). 15. Heat exchanger according to claim 14, characterized in that the flat tubes ( 1 ') have a cross section with a plurality of mutually parallel chambers ( 21 ). 16. Heat exchanger according to claim 14, characterized in that the flat tubes ( 1 ') on their opposite longer inner sides ( 22 , 23 ) with in the flow direction ( 28 ) ver running to the free end tapered ribs ( 24 ) are seen ver which are arranged opposite each other. 17. Heat exchanger according to claim 14, characterized in that the opposite inner sides ( 22 , 23 ) are designed in the manner of interlocking longitudinal teeth ( 25 , 26 ) which leave a zigzag-shaped gap ( 27 ) between them. 18. Heat exchanger according to claim 1, characterized in that the tubes ( 1 ) are composed of mutually aligned partial pipe sections ( 1 a , 1 b ), the ends of which are at least partially held in coupling pieces ( 3 ). 19. Heat exchanger according to claim 1, characterized in that the module components ( 1 A , 1 B , 10 A ) coated at least in the region of the tubes ( 1 ) and fins ( 6 , 6 ') with a good heat-conducting material, in particular with metal are.