DE20114850U1 - Heat-exchange radiator has protruberances on sheets from hollow plate plane facing inwards - Google Patents

Abstract

The radiator (1) consists of several hollow plates (4) combined into a block or pack (16) and composed of paired sheets (22), enclosing at least one cavity serving as a channel. Each sheet has protruberances (26, 33') from the hollow plate plane, facing inwards and outwards. The protruberances are produced by deformation of the material.

Description

Patent Attorney Dipl.-Ing. Walter Jackisch & Partner

Menzelstr. 40 - 70192 Stuttgart

Behr GmbH & Co. A 41 847/lrgie

Mauserstr. 3 Ol-B-055

D-70469 Stuttgart Q September 7th 2001

Heat exchanger

The invention relates to a heat exchanger of the type specified in the preamble of claim 1.

EP 0 935 115 A2 discloses a heat exchanger which consists of heat-conducting plates which are joined together in pairs and which have a large number of outward-facing ribs. Passages for a coolant are formed within a pair of heat-conducting plates. Air flows outside the plates perpendicular to the flow direction of the coolant. The ribs prevent the air from passing through the plates in a straight line and create a turbulent flow.

The invention is based on the object of creating a heat exchanger of the generic type which is simple in construction and inexpensive to manufacture.

This object is achieved by a heat exchanger having the features of claim 1.

When creating raised areas on both sides of the sheets, small drawing depths are required to achieve the required flow cross-sections. This means that hard and corrosion-resistant materials can be used for the sheets. Hard materials mean that the sheets have to be thinner and therefore the weight is reduced and/or the heat exchanger is more rigid.

The sheets in particular have a wall thickness of 0.25 mm to 0.40 mm, a width of 35 mm to 70 mm and a length of 200 mm to 270 mm. In an embodiment of the invention, the raised areas of the sheets facing the inside of the disk are designed as studs. The studs expediently have an oval base with a width of 2 mm to 7 mm and a length of about 3 mm to 25 mm. This design of the studs results in a favorable flow guide for the internal fluid. The oval design of the studs results in a high rigidity of the sheets and thus of the entire heat exchanger. In particular, sheets forming a disk are soldered to one another at contact surfaces that are formed between touching studs. This results in a solid connection that is favorable in terms of flow. The enlarged free flow cross-section leads to a reduction in the pressure loss in the internal fluid. It can be expedient for the raised areas of the sheets facing the inside of the disk to be designed as beads. In particular, sheets forming a disk are soldered at contact points between intersecting beads.

In an embodiment of the invention, it is provided that the raised areas of the metal sheets directed towards the outside of the disk are designed as elongated beads. In particular, the beads have a width of 2 mm to 4 mm and a length of 15 mm to 50 mm. This design of the beads deflects the external fluid as it flows through the disk pack both in the longitudinal direction and perpendicular to the disk surface. The flow speed of the external fluid is increased and the heat transfer is thereby increased. Adjacent disks are soldered to one another, in particular at contact points between intersecting elongated raised areas, which increases the stability of the evaporator. In particular,

The beads are of different heights along their length, with crossing beads being soldered, particularly in areas with a large height. The beads are usefully of two heights, with the ratio of the small height to the large height being between 0.2 and 0.8.

It is practical to form two parallel channels in a pane, which are delimited by edge webs arranged on the sheets on the long sides and a central web arranged in the middle in the longitudinal direction, with the webs projecting onto the inside of the pane and webs inside and on the edge of the panes being soldered to one another. The channels have a width of 15 mm to 40 mm in particular. The beads are arranged parallel and/or perpendicular and/or inclined to the longitudinal direction of the pane. Good condensate drainage is achieved in particular when the beads are arranged parallel or inclined to the longitudinal direction of the pane.

The elevations are expediently arranged in an area on the sheet in a pattern that repeats along a longitudinal section of the sheet. This achieves a uniform flow profile. The length of the longitudinal section is expediently 15 mm to 35 mm. In particular, two elevations directed towards the inside of the disk are formed in each longitudinal section in the longitudinal direction of a sheet, which makes the heat exchanger highly stable.

It is provided that in each longitudinal section in each channel two elevations are formed which are directed towards the outside of the pane and which are offset from one another in particular in the longitudinal direction of the pane, the amount by which the elevations are offset from one another being expediently

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corresponds to the longitudinal pitch. The length of the beads can be greater than the longitudinal pitch. The ratio of the transverse pitch, which is the total height of a disk, to the inlet gap width, which is the width of the gap through which the external fluid can flow between two disks adjacent on the outside, is preferably 4:3 to 4:1. The relatively small inlet gap width achieves a high heat transfer to the external fluid.

It is expedient to have openings at at least one end of the channels, which form a collecting channel in the longitudinal direction of the heat exchanger. In particular, openings are formed at each end of the channels, so that four collecting channels are formed with two channels. It is expedient to have elevations in the disc in the area of a sheet metal adjacent to the collecting channel, which are designed as inflow knobs and which in particular have a larger base area than the knobs. It is expedient for the inflow knobs to point towards the inside of the disc. The inlet and outlet of the internal fluid are arranged on the same side of the heat exchanger. This results in favorable conditions when installing the heat exchanger. It is expedient for the elevations to be produced by deep drawing. However, it can be advantageous for the elevations to be produced by embossing.

Embodiments of the invention are explained below with reference to the drawing.

Fig. 1 is an exploded view of a heat exchanger constructed from discs,

Fig. 2 a perspective view of two sheets between which the external fluid flows,

Fig. 3 is a detail of a view of a disc from the discs shown in Fig. 2,

Fig. 4 is a section through a disc package in a plane along the line IV-IV in Fig. 3,

Fig. 5 is a schematic representation of the flow pattern in the heat exchanger shown in Fig. 1,

Fig. 6 another embodiment of the sheets,

Fig. 7 shows a detail of a view of a disc according to Fig. 6,

Fig. 8 another embodiment of the sheets,

Fig. 9 shows a detail of a view of a disc according to Fig. 8,

Fig. 10 another embodiment of the sheets,

Fig. 11 is a detail of a view of a sheet according to Fig. 10 with the beads of the adjacent sheet shown,

Fig. 12 is a section along the line XII-XII in Fig. 10.

Fig. 1 shows a heat exchanger 1, which comprises a disk pack 16, which is made up of sheets 2. Two

Identical sheets 2 are joined together rotated by 180° around the longitudinal axis to form a disk 38 (Fig. 3). The sheets 2 forming a disk 38 can also have a different structure, in particular two mirror-image sheets can be joined together to form a disk. The sheets 2 each have two passages 18 at their longitudinally arranged ends, which are arranged next to one another in the width of the sheets 2 and which form a total of four collecting channels 17. Each collecting channel 17 extends in the width B of the heat exchanger 1. Each disk 38 comprises a cavity which contains two channels which are delimited by a central web 13 and two edge webs 12 as well as by the inner sides of the sheets 2. The channels extend in the longitudinal direction of the disks 38, i.e. in the direction of the height H of the heat exchanger 1. Inside the disks 38, the inner fluid, for example a coolant, flows in the channels.

The outer fluid flows perpendicular to the flow direction of the inner fluid in the direction indicated by the arrow 3. On the sheets 2, knobs 10 directed towards the inside of the disk and beads 9 directed towards the outside of the disk are arranged. The disk package 16 is made up of stacked disks 38. On the sides directed towards the inside of the disk, the sheets 2, which form a disk 38, are soldered together at the touching knobs 10, the central web 13 and the edge webs 12. The individual disks 38 are soldered together at the contact points of the beads 9 and the passages 18. The passages 18 touch each other at a circular ring surface 19 (Fig. 2), which represents a good contact surface for soldering. The knobs 10 and the beads 9 are advantageously produced by deep drawing or embossing. Advantageously,

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the webs 12, 13, the elevations 9, 10 and the passages are manufactured in one tool.

The disk pack 16 is delimited on one side in the direction of the width B of the heat exchanger 1 by an end disk 6 which is made of sheet metal and has an inlet 4 and an outlet 5 for the internal fluid. The inlet 4 and the outlet 5 are designed as pipe connections, the outlet 5 having a larger diameter than the inlet 4. On the opposite side of the heat exchanger 1, the disk pack 16 is delimited by the end disk 7 which is also made of sheet metal and which is connected to the disk pack 16 via a connecting disk 8. The connecting disk 8 has two openings which correspond to the openings of the two lower collecting channels 17 and are arranged congruently with them. The end disk 7 has a deflection channel 20 which creates a fluidic connection between the two collecting channels 17 connected to it. The deflection channel 20 can also be designed as a pipe, for example.

In Fig. 2, two sheets 2 are shown, between which the external fluid flows on the side of the sheets 2 facing the outside of the pane in the direction shown by the arrow 3. On the side of the sheets 2 facing the outside of the pane, the beads 9 are arranged transversely to the longitudinal direction of the sheets 2. The beads 9 are inclined to the longitudinal axis by an angle that can advantageously be between 20° and 30". However, different angles of inclination are also possible. The beads are offset in the longitudinal direction of the sheets 2 by the length of the longitudinal section L shown in Fig. 3. The length of the longitudinal section L is 17.5 mm. Also deviating from this

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Different lengths, in particular from 15 mm to 35 mm, can be useful, especially with different inclinations of the beads 9. Due to the beads 9 on the outer sides of the disks 38, the external fluid is redirected in the direction of the arrow 3 both in the width B and in the height H of the heat exchanger 1 when passing through the heat exchanger 1.

On the side of the sheets 2 facing the inside of the pane, on which the inner fluid flows in the direction indicated by the arrow 11, studs 10 are arranged. The studs 10 advantageously have a length of 3 mm to 7 mm, in particular 4.6 mm, and a width of 2 mm to 4 mm, in particular 2.7 mm. In the longitudinal direction of the sheets, in a longitudinal section L on each sheet 2, two studs 10 are arranged on a channel and one stud 10 is arranged at a distance in the longitudinal direction that corresponds approximately to half the length of the longitudinal section L. In the area of the sheet 2 adjacent to the passage, two inflow studs 14 are arranged that are directed towards the inside of the pane and have a larger base area than the studs 10. The bead 15 adjacent to the inflow studs 14 is shortened for reasons of space. The edge webs 12 follow the contour of the passages 18 in the area of the through-holes 18 and merge into the middle web 13 in the area of the latter, so that when the inner sides of adjacent sheets 2, which form a disk 38, are joined together, each channel is closed off at the top and bottom and the inner fluid can only flow out of or into the channel through the through-holes 18 forming the collecting channel 17.

Fig. 3 illustrates the position of the elevations 9, 10 in the direction of the width B of the heat exchanger 1. The beads 9 of adjacent discs 38 cross each other at the three contact points 21 of each bead 9. At the contact points, the

Beads 9 are soldered together. The studs 10 are arranged between the beads 9 on the opposite side of a sheet 2, wherein studs 10 of adjacent sheets 2, which form a disk 38, touch one another flatly at contact surfaces 22 and are soldered together.

It may be useful for the knobs 10 to only touch one another at certain points. It may be useful for the beads 9 to touch one another over their entire surface. The edge webs 12 and the center webs 13 of two sheets 2 forming a disk 38 touch one another and are soldered together, with the width of the contact surface being designed in such a way that good soldering is achieved.

A disk 38 has a height that corresponds to the transverse pitch Q. The inlet gap width S, through which the external fluid can flow between two disks 38, is one quarter to three quarters, in particular approximately one third, of the transverse pitch Q. The arrow 3, which indicates the flow direction of the external fluid through the disk pack 16, illustrates the deflection of the external fluid by the beads 9 in the direction of the width B of the heat exchanger 1.

In Fig. 5, the flow direction 11 of the inner fluid through the heat exchanger 1 shown in Fig. 1 is shown. The inner fluid flows through the inlet 4 into a section of the collecting channel 17 in the channel row 23 arranged downstream of the flow direction of the outer fluid. The inlet 4 and the outlet 5 open into upper collecting channels 17a, and the collecting channels 17 arranged on the opposite side of the channels are lower collecting channels 17b. The four collecting channels 17 are each divided into two sections by a partition wall 25. The inner fluid flows from the first section of the upper collecting channel 17a

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in channels of the channel row 23 into a section of the lower collecting channel 17b, from there into a section of the upper collecting channel 17a fluidically separated from the inlet 4 by a partition wall 25 and through further channels of the channel row into a further section of the lower collecting channel 17b of the channel row 23.

In the end plate 7, the fluid is diverted from the channel row 23 into the channel row 24, which is arranged upstream of the flow direction of the external fluid, and flows in this in the opposite flow direction to the channel row 23 to the outlet 5, where it exits the heat exchanger 1. More than one partition 25 can be provided in a collecting channel 17. The partition 25 can be designed as a separate component. However, it can also be integrated into a sheet 2 in which, for example, only a raised area is arranged as a soldering point instead of the passage 18.

Fig. 6 and 7 show a further arrangement of the beads and the knobs 10 on a disk 28. Between two beads 9, which are inclined to the longitudinal axis of the sheet 28, two knobs 10 are arranged. In a disk 39 shown in Fig., the beads 9 touch each other at four contact points 29 on each bead 9. In the longitudinal direction of the disks 28, the beads 9 have approximately one and a half times the length of the longitudinal section L. The knobs are each arranged in a space formed by the beads 9 of two adjacent disks 39. The knobs 10 touch each other flatly at contact points 30 and are soldered to each other. The central web 13 has widenings 31 and the edge webs 12 have widenings 32. The widenings 31 and 32 correspond approximately in the longitudinal direction

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the disk 28 halved studs 10. The widenings 31, 32 lead to an increased stability of the disk 39.

8 and 9 show a further arrangement of the elevations 9, 10 on a sheet 33. The beads 9 have a length in the longitudinal direction of the sheet 33 which corresponds to approximately three quarters of the length of the longitudinal section L. Two rows 34 and 35 of beads 9 are arranged on each channel, which are inclined at opposite angles to the longitudinal direction, but by the same angular amount. The studs 10 are arranged corresponding to the studs 10 in Figs. 6 and 7. In a disk 40 made of sheets 33 shown in Fig. 9, a bead 9 of row 34 is continued by a bead 9 of row 35 of a sheet 33 adjacent on the outside of the disk. The beads 9 of rows 34 and 35 each have two contact points 36 with beads 9 of adjacent disks 40. The studs 10 have contact surfaces 38 within a disk 40. The formation of the beads 9 in two rows 34 and 35 leads to a stronger deflection of the external fluid in the direction of the width B of the heat exchanger 1.

A further variant of a sheet 41 is shown in Figs. 10 to 12. The elevations projecting onto the inside of a disk formed from two sheets 41 are designed as beads 44. The beads 45 projecting onto the outside of the disks have a low height a and a high height b in a central region (Fig. 12). The ratio of the low height a to the high height b is in particular 0.2 to 0.8.

The beads 44 and 45 are arranged on each channel in two rows 42, 43, with the beads 44, 45 in a row 42 in opposite directions, but at the same angle.

amount to the longitudinal direction, like the beads in a row 43.

In the longitudinal direction of the sheet 41, beads 44 directed towards the inside of a disc and beads 45 directed towards the outside are arranged alternately. In each longitudinal section L, one bead 44 and one bead 45 are arranged in each row.

In Fig. 11, a sheet 41 is shown with the outward-facing beads 45 of an adjacent sheet 41. This arrangement is obtained by joining two identical sheets rotated by 180° around the longitudinal axis. The beads 45 of adjacent sheets 41 are soldered at contact points 46 and the beads 44 at contact points 47. In order to achieve contact surfaces, however, sheets 41 can also be joined together with sheets with a mirror-image arrangement of the beads 44, 45 to form disks.

Claims (25)

1. Heat exchanger, in particular a coolant evaporator, with a plurality of disks ( 38 , 39 , 40 ) assembled to form a disk package ( 16 ), each of which is formed from sheets ( 2 , 28 , 33 , 41 ) joined together in pairs and encloses between them at least one cavity designed as a channel, which is delimited by the inner sides of the sheets ( 2 , 28 , 33 , 41 ), wherein an inner fluid flows in the longitudinal direction of the disks ( 38 , 39 , 40 ) in the channel and an outer fluid flows on the outer side of the disks ( 38 , 39 , 40 ) essentially transversely to the flow direction of the inner fluid, and wherein each sheet ( 2 , 28 , 33 , 41 ) has elevations ( 9 , 10 , 14 , 15 ) , 44 , 45 ) from the sheet plane, which are formed by material deformation, characterized in that the sheets ( 2 , 28 , 33 , 41 ) have elevations ( 9 , 10 , 14 , 15 , 44 , 45 ) directed both towards the inside of the pane and towards the outside of the pane. 2. Heat exchanger according to claim 1, characterized in that the sheets ( 2 , 28 , 33 , 41 ) have a wall thickness of 0.25 mm to 0.40 mm, a width of 35 mm to 75 mm and a length of 200 mm to 270 mm. 3. Heat exchanger according to claim 1 or 2, characterized in that the elevations of the sheets ( 2 , 28 , 33 ) directed towards the inside of the disc are designed as knobs ( 10 ). 4. Heat exchanger according to claim 3, characterized in that the knobs ( 10 ) have an oval base with a width of 2 mm to 4 mm and a length of 3 mm to 25 mm. 5. Heat exchanger according to claim 3 or 4, characterized in that sheets ( 2 , 28 , 33 ) forming a disk ( 38 , 39 , 40 ) are soldered to one another at contact surfaces ( 22 , 30 , 37 ) which are formed between contacting knobs ( 10 ). 6. Heat exchanger according to claim 1 or 2, characterized in that the elevations of the sheets ( 41 ) directed towards the inner side of the disc are designed as beads ( 44 ). 7. Heat exchanger according to claim 6, characterized in that sheets ( 41 ) forming a disk are soldered at contact points ( 47 ) between crossing beads ( 44 ). 8. Heat exchanger according to one of claims 1 to 7, characterized in that the elevations of the sheets ( 2 , 28 , 33 , 41 ) directed towards the outside of the disc are designed as beads ( 9 , 45 ). 9. Heat exchanger according to claim 8, characterized in that the beads ( 9 , 45 ) have a width of 2 mm to 4 mm and a length of 15 mm to 50 mm. 10. Heat exchanger according to claim 8 or 9, characterized in that adjacent discs ( 38 , 39 , 40 ) are soldered to one another at contact points ( 21 , 29 , 36 , 45 ) between crossing beads ( 9 , 45 ). 11. Heat exchanger according to one of claims 6 to 10, characterized in that the beads ( 45 ) are formed with different heights over their length, wherein crossing beads are soldered in particular in regions with a large height (b). 12. Heat exchanger according to claim 11, characterized in that the beads ( 45 ) have two heights, the ratio of the small height (a) to the large height (b) being 0.2 to 0.8. 13. Heat exchanger according to one of claims 1 to 12, characterized in that two parallel channels are formed in a disk ( 38 , 39 , 40 ), which are delimited by edge webs ( 12 ) arranged on the longitudinal sides of the sheets ( 2 , 28 , 33 , 41 ) and a central web ( 13 ) arranged in the middle in the longitudinal direction, wherein the webs ( 12 , 13 ) project onto the inside of the disk and webs ( 12 , 13 ) in the interior and on the edge of the disks ( 2 , 28 , 33 ) are soldered to one another. 14. Heat exchanger according to claim 13, characterized in that the channels have a width of 15 mm to 40 mm. 15. Heat exchanger according to one of claims 1 to 14, characterized in that the beads ( 9 , 45 ) are arranged parallel and/or inclined to the longitudinal direction of the disc ( 38 , 39 , 40 ). 16. Heat exchanger according to one of claims 1 to 15, characterized in that the elevations ( 9 , 10 , 44 , 45 ) are arranged in a region on the sheet ( 2 , 28 , 33 , 41 ) in a pattern on the sheet ( 2 , 28 , 33 , 41 ) which repeats itself along a longitudinal section (L) of the sheet ( 2 , 28 , 33 , 41 ). 17. Heat exchanger according to claim 16, characterized in that the length of the longitudinal section (L) is 15 mm to 35 mm. 18. Heat exchanger according to one of claims 16 or 17, characterized in that in each longitudinal section (L) in the longitudinal direction of a sheet ( 2 , 28 , 33 , 41 ) at least two elevations directed towards the inside are formed on a sheet ( 2 , 28 , 33 , 41 ). 19. Heat exchanger according to one of claims 16 to 18, characterized in that in each longitudinal section (L) in each channel two elevations directed towards the outside of the disc are formed on a sheet ( 2 , 28 , 33 , 41 ) on the outside, which are offset from one another in particular in the longitudinal direction of the disc ( 38 , 39 , 40 ). 20. Heat exchanger according to one of claims 1 to 19, characterized in that the ratio of the transverse pitch (Q), which designates the total height of a disk ( 38 , 39 , 40 ), to the inlet gap width (S), which designates the width of the gap through which the external fluid can flow between two disks ( 38 , 39 , 40 ) adjacent on the outside, is 4:3 to 4:1. 21. Heat exchanger according to one of claims 1 to 21, characterized in that passages ( 18 ) are formed at at least one end of the channels, which form a collecting channel ( 17 ) in the longitudinal direction of the heat exchanger ( 1 ). 22. Heat exchanger according to claim 21, characterized in that in the region of a sheet ( 2 , 28 , 33 , 41 ) adjoining the collecting channel ( 17 ), elevations are formed in the sheet ( 2 , 28 , 33 , 41 ), which are designed as inflow knobs ( 14 ) and which in particular have a larger base area than the knobs ( 10 ). 23. Heat exchanger according to one of claims 1 to 22, characterized in that the inlet ( 4 ) and outlet ( 5 ) of the internal fluid are arranged on the same side of the heat exchanger ( 1 ). 24. Heat exchanger according to one of claims 1 to 23, characterized in that the elevations ( 9 , 10 , 14 , 44 , 45 ) are produced by deep drawing. 25. Heat exchanger according to one of claims 1 to 23, characterized in that the elevations ( 9 , 10 , 14 , 44 , 45 ) are produced by embossing.