US20090101322A1

US20090101322A1 - Heat Exchange Device

Info

Publication number: US20090101322A1
Application number: US12/227,180
Authority: US
Inventors: Wolfgang Hahmann; Rudolf Kunz
Original assignee: Hydac System GmbH
Current assignee: Hydac System GmbH
Priority date: 2006-06-03
Filing date: 2007-02-27
Publication date: 2009-04-23
Also published as: WO2007140829A1; CN101438120A; DE102006026075A1; EP2024704A1

Abstract

Heat exchange device with a plate element (1) which has a shaped part (5) which extends over a heat exchange surface, is of at least partly flexible design and forms a partial boundary of a cavity (13), through which a heat transfer medium can flow and which is tightly closed off on the base side by a web (11) which forms on the heat exchange surface the contact surface for the heat transfer to a body (3), against which body the plate element (1) can be placed, wherein a flexible retaining plate (21) for pressing the plate element (1) against the body (3) rests on that top side of the shaped part (5) which is remote from the heat exchange surface on the base side, and wherein the flexibility of retaining plate (21) and the deformability of shaped part (5) and web (11) on the base side are selected in such a way that the plate element (1) can be adapted to the geometry of the body (3).

Description

The invention relates to a heat exchange device having a plate element which has a shaped part which extends over a heat exchange surface.
In mechanical devices, for example, machine tools, heat loss from drives and highly loaded bearings as well as process-generated heat sources cause temperature elevations in regions in bearing parts if no measures to dissipate heat are taken. For high-precision machines, the deformation which is caused by heating up of components adversely affects the dimensional stability of the workpiece in a profound way. Providing cooling as a countermeasure is often extremely difficult or cannot be carried out since structural circumstances preclude the integration of cooling means such as holes or channels for a flowing heat transfer medium. Such holes of channels result not only in an adverse etfect on the bearing capacity of highly loaded components, but also result in greater cost of the mechanical device.
With respect to the aforementioned, the object of the invention is to make available a heat exchange device which is characterized by simple construction, and yet enabling dedicated heat transfer at designated locations, as near as possible to the heat generating site or to a transition site to a thermally sensitive assembly.
This object is achieved according to the invention by a heat exchange device which has the features of claim 1 in its entirety.
Accordingly, the invention calls for a plate element in the form of a flexible cooling collar (or analogously a heating collar, to which reference is made below), which conforms to the machine parts to be cooled (or heated) and which due to flexible conformation forms a large contact surface for heat transfer. In this way in-situ cooling is also enabled on components into which internal cooling systems cannot be integrated. In addition, one special advantage is that the device according to the invention can also be added later. The device according to the invention can be of modular design and can be flexibly made larger or smaller by attaching the desired number of plate elements or collars and connecting them among one another, wherein the connection can be made as a parallel or series connection.
In advantageous embodiments the shaped part can be formed from an elastomer, preferably from nitrile rubber NBR. A shaped part such as this on the one hand has the desired flexibility and on the other hand is resistant to conventional heat transfer media, for example, to water-glycol and water with anticorrosion agents. Moreover, there is resistance to other fluids, such as oil, which can be found in the vicinity of mechanical systems.
The bottom-side web which tightly seals the cavity for the heat transfer medium against the shaped part and which forms the contact surface for heat exchange is formed by a film which has been made thin compared to the wall thickness of the shaped part, preferably likewise from nitrile rubber NBR.
The retaining plate which rests on the top of the shaped part, in order to apply a compressive force to the latter to press the plate element against the pertinent body, is preferably formed by a thin metal plate. Its thickness can be chosen such that it enables, by hand, the adaptation of the plate element to the geometry of the body to be cooled, but at the same time has a thickness such that it can transfer the necessary contact forces.
The arrangement can be made such that the heat exchange surface has a rectangular outline which is rounded on the corner regions, the retaining plate extending superficially over the entire heat exchange surface while exposing openings in the access regions for supply and discharge of the heat transfer medium. The collar thus has the shape of a closed, flat plate which is planar in the undeformed state, the planar surface on the top being interrupted only by access openings for supply and delivery of the heat transfer medium.
In advantageous embodiments the shaped part forms a plate with a planar sealing edge which extends continuously along the outside edge of the heat exchange surface and to which the bottom-side web is attached with the formation of a seal, preferably by cementing, the plate in the region within the sealing edge running offset away from the bottom-side web in order to form the inner cavity between the plate and the bottom-side web. In this way the space for the heat transfer medium extends over the entire surface region of the plate, aside from the outer sealing edge, so that advantageously heat transfer can accordingly take place effectively over a large area.
In especially advantageous embodiments, on the side of the plate facing the bottom-side web, there are burls projecting into the cavity as spacers between the bottom-side web and the plate and for producing turbulence of the flow of the heat transfer medium. The burls, which can be made in one piece in a large number on the shaped part, keep the film provided on the bottom-side web not only at a defined distance from the opposite wall of the cavity, but due to the generation of turbulence also provide for good mixing of the heat transfer medium flowing into the cavity and thus likewise contribute to an increase of efficiency.
Preferably the arrangement is such that the plate has a connecting branch molded to the top for supply and discharge of heat medium into and out of the cavity, the connecting branch penetrating the access openings which are made in the retaining plate which adjoins on the top. In this way there are simple connection possibilities for the lines which run on the outside of the pertinent body which is to be cooled, and connections between several plate elements can be formed without difficulty.
Preferably the plate which forms the shaped part on its top in the central region above the cavity forms a planar contact surface for the retaining plate, on the sealing edge which extends along the outside of the heat exchange surface at least one bead being formed which projects on the top and which extends peripherally along the edge region in order to cause an increase of the contact forces which are applied by the retaining plate and which act on the sealing edge.

The invention is detailed below using the drawings:

FIG. 1 shows a schematically simplified perspective oblique view of one embodiment of the heat exchange device according to the invention, the plate element being shown in the state matched to one wall section of a body to be cooled and the wall section of the body being shown only schematically;

FIG. 2 shows a perspective oblique view similar to FIG. 1, an example being shown with a plate element which is made more elongated relative to FIG. 1 and which is matched to a circular cylindrical outside wall of a body;

FIG. 3 shows a perspective oblique view in which the plate element made according to FIG. 1 is shown in the undeformed state of a planar plate;

FIG. 4 shows a perspective oblique view, looking at the top solely of the shaped part of the plate element from FIG. 3;

FIG. 5 shows a perspective oblique view, looking at the underside of the shaped part from FIG. 4;

FIG. 6 shows a top view of the embodiment from FIGS. 3 to 5 shown approximately at half the size of one practical embodiment;

FIG. 7 shows a section drawn approximately in natural size along line VII-VII from FIG. 6;

FIG. 8 shows a section drawn approximately in natural size along line VIII-VIII from FIG. 6;

FIG. 9 shows a cross section of the shaped part according to cutting line IX-IX from FIG. 4, shown approximately on a scale corresponding to FIG. 4;

FIG. 10 shows a partial section of the region designated as X in FIG. 9, shown on a scale more or less doubled compared to natural size, and

FIG. 11 shows a perspective oblique view of one embodiment drawn on a substantially smaller scale, provided with retaining clamps for placing the plate element on a body which is not shown.

The invention is explained below using the embodiment of a cooling collar through which a heat transfer medium can flow, for example, a conventional heat transfer fluid, such as water-glycol or water with anticorrosion agents, in conjunction with a coolant circuit which is not shown. As indicated briefly above, the exchange device according to the invention could also be used as a heating collar for dedicated in-situ heating of desired sections, the plate element being connected to a heater system and a heated heat transfer medium flowing through it.
FIGS. 1 and 2 illustrate application examples for which a plate element 1 which forms a cooling collar is deformed for respective matching to a wall section of a body 3, in the example from FIG. 1 the plate element 1 being adapted to the staggered outside shape of the body 3. FIG. 2 shows one example in which the plate element 1 compared to the example from FIG. 1 has a more strongly elongated shape and is adapted to a wall section of a circular cylindrical body 3. Retaining means for placement against the body 3 are omitted in FIGS. 1 and 2, as well as the connecting lines for supply and discharge of the used, flowable heat transfer medium.
The main component of the embodiment of the plate element 1, which is to be described here and which is shown in its entirety in particular in FIG. 3 in an oblique top view and in the sectional views of FIGS. 7 and 8, is a shaped part formed by a flexible plate 5 which is shown separately in FIGS. 4 and 5 and which extends superficially over the entire heat exchange surface. The plate 5 has the outline of a rectangle with rounded corner regions. As a comparison of FIGS. 1 and 2 shows, the outline shape can be more or less elongated for adaptation to circumstances. The plate 5, which acts as a shaped part in this example, is formed from an elastomer, in a special case from a nitrile rubber NBR. The use of such a material is advantageous in that there is both sufficient flexibility for adaptation and conformation of the plate element 1 to the corresponding contours, and there is also insulating action to the outside and resistance to the fluids under consideration. When the plate element 1 is made as a shaped part with a wall thickness approximately in the range from 3 to 5 millimeters, the necessary compression strength, for example, for media pressures of approximately 2 bar, also arises.
As is best shown in FIGS. 4, 7 and 8, the plate 5 on its top has planar wall regions which are offset to one another, specifically a central part 7 which extends along most of the plate surface and a sealing edge 9 which surrounds the central part. As is especially apparent from FIGS. 7 and 8, the planar central part 7 is offset relative to the surrounding sealing edge 9 such that a gap is formed between the plane defined by the underside of the sealing edge 9 and the underside of the central part 7. Thus, when a tight termination is formed by a bottom-side web 11 as a bottom-side termination on the underside of the sealing edge 9, in the embodiment a film which is cemented to the underside of the sealing edge 9, then a cavity 13 which is used as a flow chamber for the pertinent heat transfer medium is formed in the gap region between the underside of the central part 7 and the web 11. A plurality of burls 15 are molded onto the underside of the central part 7 of the plate 5; they are not all numbered in the figures and they project in the direction to the web 11 within the cavity 13. These burls 15 form both spacer elements which keep the web 11 at a uniform distance from the opposing wall of the cavity 13 so that the web 11, with the plate 5 undeformed, runs in a common plane with the underside of the sealing edge 9, but the burls 15 also cause turbulence in the flow of the heat transfer medium within the cavity 13; this causes good mixing and an increase of the efficiency of the heat transfer. On the underside of the sealing edge 9 the web 11 is sealed, in addition to cementing, by means of strand-shaped sealing elements which are not shown in the drawings and which sit in grooves 17 which are made peripherally on the underside of the sealing edge 9.
Placed on the longitudinal center line of the rectangular shape of the plate 5, on the two end regions of the cavity 13 which border the sealing edge 9, that is, in the transition region between the central part 7 and the sealing edge 9, connecting branches 19 are made in one piece with the plate 5 and extend perpendicular to the plane of the plate in the illustrated example. Depending on local circumstances and connection conditions, these connecting branches, however, could also be provided in a different tilt relative to the plane of the plate or could be made bent or angled. At the wall thickness of the shaped part which is formed by the plate 5, which thickness remains essentially the same over the plate surface, because the central part 7 to form the cavity 13 is offset relative to the heat exchange surface which is defined by the web 11 which adjoins the underside of the sealing side 9, a step is formed between the top of the central part 7 and the top of the sealing edge 9, as is apparent most clearly from FIGS. 7 to 9. As components of a retaining means for pressing the plate element 1 which is used as the cooling collar against the pertinent body 3, there is a retaining plate 21 in the form of a sheet metal plate with a wall thickness which is chosen such that manual deformation is possible for matching the plate element 1 to the outside contour of the pertinent body 3. The retaining plate 21 which extends superficially with the same surface area as the plate 5 over the entire heat exchange surface has openings 23 which are aligned to the connecting branches 19 for passage of the connecting branches. The retaining plate 21 which rests on the top of the planar central part 7 enables transfer of a contact force to the plate 5, for example, using retaining clamps 25 which extend over the edge of the retaining plate 21 (FIG. 11).
For reliable operation care must be taken that the contact force produced by way of the retaining plate 21 is effective especially on the sealing edge 9. Since the top of the sealing edge 9, as already mentioned, is staggered relative to the plane of the top of the central part 7, that is to say, is offset relative to the plane of the retaining plate 21 which rests on the central part 7, between the top of the sealing edge 9 and the facing underside of the retaining plate 9, there is an edge body 27 which constitutes a spacer body by way of which the contact force is transferred from the retaining plate 21 to the sealing edge 9, see FIGS. 7 and 8.
As an additional special means for increasing the contact pressure acting on the sealing edge 9, on the top of the plate two annular beads 29 and 31 are formed which project against the retaining plate 21 and whose position can be seen most clearly from the highly enlarged detail from FIG. 10. For active contact force which is applied by way of the retaining plate 21 and the edge body 27 and for the resilience of the plate 5 which as the shaped part consists of an elastomer, the beads 29, 31 in the operating state of the plate element 1 are pressed flat, see FIG. 8. As FIG. 7 shows, only a short longitudinal section of the annular bead 29 in the region of the openings 23 for the connecting branches 19 is exposed and therefore is not pressed flat at this location.
As already mentioned, for a wall thickness of the plate 5 which is used as a shaped part and which for practical examples can be in the range between 3 and 5 millimeters, there are both sufficient compressive strength when it is an elastomer, such as NBR, and also deformability so that the plate element 1 can be matched to the pertinent body 3 by deformation of the retaining plate 21. The flexibility of the plate element 1 is not adversely affected either by the bottom-side termination element which forms the contact surface, since in this example it is a flexible web 11 which can be thin-walled as a film, for example, in the form of an NBR film.
The entire plate element 1 can be applied to the pertinent body 3 by means of a heat conducting paste in order to promote heat transfer.

Claims

1. A heat exchange device having a plate element (1) which has a shaped part (15) which is at least partially designed to be flexible, which extends over the heat exchange surface, and which forms the partial boundary of a cavity (13) through which a heat transfer medium can flow and which is sealed tight on the bottom by a web (11) which on the heat exchange surface forms the contact surface for heat transfer with the body (3) against which the plate element (1) can be placed, resting on the top of the shaped part (5) which faces away from the bottom-side heat exchange surface, there being a flexible retaining plate (21) for pressing the plate element (1) against the body (3) and the flexibility of the retaining plate (21) and the deformability of the shaped part (5) and bottom-side web (11) being chosen such that the plate element (1) can be adapted to the geometry of the body (3).

2. The heat exchange device according to claim 1, wherein the shaped part (5) can be formed from an elastomer, preferably from nitrile rubber NBR.

3. The heat exchange device according to claim 1, wherein the bottom-side web (11) is formed by a film which has been made thin compared to the wall thickness of the shaped part (5), preferably from nitrile rubber NBR.

4. The heat exchange device according to claim 1, wherein the retaining plate (21) is formed by a thin metal plate.

5. The heat exchange device according to claim 4, wherein the heat exchange surface has a rectangular outline which is rounded on the corner regions and wherein the retaining plate (21) extends superficially over the entire heat exchange surface while exposing openings (23) in the access regions for supply and discharge of the heat transfer medium.

6. The heat exchange device according to claim 1, wherein the shaped part forms a plate (5) with a planar sealing edge (9) which extends continuously along the outside edge of the heat exchange surface and to which the bottom-side web (11) is attached with the formation of a seal, and wherein the plate (5) in the region within the sealing edge runs offset away from the bottom-side web (11) in order to form the inner cavity (13) between the plate (5) and the bottom-side web (11).

7. The heat exchange device according to claim 6, wherein on the side of the plate (5) facing the web (11) there are burls (15) projecting into the cavity (13) as spacers between the bottom-side web (11) and the plate (5) and for producing turbulence of the flow of the heat transfer medium.

8. The heat exchange device according to claim 7, wherein the plate (5) has connecting branches (19) which are molded to the top for supply and discharge of heat medium into and out of the cavity and which penetrate the openings (23) which are made in the retaining plate (21) which adjoins on the top.

9. The heat exchange device according to claim 8, wherein the plate (5) on its top in the region (7) above the cavity (13) forms a planar contact surface for the retaining plate (21), and on the sealing edge (9) which extends along the outside of the heat exchange surface has at least one bead (29, 31) which projects on the top and which extends peripherally along the edge to increase the contact forces which are applied by the retaining plate (21) and which act on the sealing edge (9).

10. The heat exchange device according to claim 3, wherein the film provided as the bottom-side web (11) is connected by cementing to the sealing edge (9) of the shaped part (5).