Heat exchanger with a circumferential seal

Abstract

A heat exchanger may include a plate, a seal and a cover. The plate may have at least two receiving grooves having a respective groove base, an intermediate region disposed in a plane between a plurality of rim holes, and a ramp extending between the intermediate region and the respective groove base of the at least two receiving grooves. The seal extends in the at least two receiving grooves. The ramp may be rounded at a transition to the receiving grooves with a first radius and at a transition to the intermediate region with a second radius, and the ramp may be inclined between 20<<65 relative to the intermediate region or has an S-shaped progression. An inflection point of the plate may be arranged in a region from 10% to 80% of a height difference between the intermediate region and the respective groove base.

Claims

1. A heat exchanger comprising: a plate, a seal and a cover; the plate including at least two receiving grooves that are spaced apart in parallel and extend in a longitudinal direction of the plate, the at least two receiving grooves arranged on two mutually opposite sides of the plate and configured to receive a lateral projection of the cover; the at least two receiving grooves having a respective groove base; wherein the plate has at least three rim holes arranged in a plane spaced apart from one another in parallel and spaced apart from the at least two receiving grooves, the at least three rim holes extending perpendicular to and between the at least two receiving grooves; an intermediate region disposed in the plane between at least two rim holes of the at least three rim holes, wherein the intermediate region is arranged spaced apart from the respective groove base of the at least two receiving grooves in parallel by a height difference; at least two ramps respectively disposed between the intermediate region and the respective groove bases, wherein the at least two ramps extend parallel to a longitudinal direction of the at least three rim holes and are spaced apart from one another in parallel; wherein the seal includes an encircling sealing cord; the seal extending in the at least two receiving grooves and via a seal web over a corresponding one of the at least two ramps and the intermediate region; wherein the at least two ramps are rounded with a first radius at a transition to the at least two receiving grooves and with a second radius at a transition to the intermediate region; and wherein the at least two ramps have a curved profile with an inflection point arranged in a region of 10% to 80% of the height difference from the respective groove base of the at least two receiving grooves to the intermediate region.

2. The heat exchanger as claimed in claim 1, wherein a ratio of the height difference to a diameter of a section of the seal in the at least two receiving grooves in a non-compressed state of the seal is 0.7 to 2.5.

3. The heat exchanger as claimed in claim 2, wherein the ratio is between 1.0 and 2.0.

4. The heat exchanger as claimed in claim 1, wherein a ratio of the first radius to a third radius of a section of the seal in the at least two receiving grooves in a compressed state of the seal is 0.3 to 3.0.

5. The heat exchanger as claimed in claim 1, wherein at least one rim hole has a longitudinal end facing toward a respective one of the at least two receiving grooves that is disposed between 1 mm to 15 mm closer to the respective one of the at least two receiving grooves than a transition of at least one of the at least two ramps to the intermediate region.

6. The heat exchanger as claimed in claim 1, wherein at least one of the at least two ramps is configured as a groove that extends parallel to the longitudinal direction of the rim holes and the seal runs in sections in the groove, wherein a ratio of a degree of groove filling by the seal in the groove to a degree of groove filling by the seal in at least one of the at least two receiving grooves in a compressed state of the seal is between 1.0 and 1.4.

7. The heat exchanger as claimed in claim 1, wherein the at least two ramps have a first width and the intermediate region has a second width, and wherein a ratio of the first width to the second width is between 0.3 and 1.0.

8. The heat exchanger as claimed in claim 1, wherein the seal further includes at least one preload web for reducing tensile stresses on the seal, wherein the at least one preload web is arranged parallel to the seal web.

9. The heat exchanger as claimed in claim 1, wherein the cover is configured as a box and includes at least two lateral projections respectively running along a longitudinal side on an outer region of the box at two mutually opposite sides, wherein the at least two lateral projections extend in the at least two receiving grooves and have a protrusion projecting longitudinally beyond the seal.

10. The heat exchanger as claimed in claim 1, wherein the cover is configured as a box and includes a box foot, wherein the box foot has a projection arranged on a longitudinal side of an outer region of the box foot, there is arranged a projection (20) for positioning the box on the plate.

11. The heat exchanger as claimed in claim 1, wherein the at least two receiving grooves have a wall at least partially bent and configured to engage behind at least a part of the lateral projection of the cover.

12. The heat exchanger as claimed in claim 11, wherein the wall of the at least two receiving grooves includes a plurality of crenellations having a repetitive geometrical shape and arranged symmetrically with respect to the at least three rim holes of the plate, and wherein the plurality of crenellations are bendable around the lateral projection of the cover.

13. The heat exchanger as claimed in claim 1, further comprising a side part insertable through at least one of the at least three rim holes of the plate, wherein the side part includes a side part protrusion for connecting the plate to the cover, and wherein an average spacing between the side part and an adjacent, outer flat tube has a value, wherein a ratio of the side part protrusion to the value of the average spacing is between 0.3 and 0.7.

14. The heat exchanger as claimed in claim 1, wherein the at least three rim holes have an equal contour and an equal area.

15. The heat exchanger as claimed in claim 1, wherein at least two of the rim holes arranged at a respective lateral end of the plate have an area which differs from an area of another rim hole by a factor of 0.8 to 1.3.

16. The heat exchanger as claimed in claim 1, wherein a plurality of intermediate regions are arranged interposed between the at least three rim holes, and wherein at least two ramps are associated with each of the plurality of intermediate regions and extend between a corresponding one of the plurality of intermediate regions and the respective groove base of the at least two receiving grooves.

17. The heat exchanger as claimed in claim 1, wherein a ratio of the second radius to a third radius of a section of the seal in the at least two receiving grooves in a compressed state of the seal is 0.3 to 3.0.

18. A heat exchanger, comprising: a cover including at least two projections; a plate including at least two receiving grooves disposed spaced apart from one another in parallel and extending in a longitudinal direction of the plate, the at least two receiving grooves having a respective groove base; wherein the at least two receiving grooves are arranged on mutually opposite sides of the plate and are configured to receive a respective one of the at least two projections of the cover; the plate further including a plurality of rim holes arranged in a plane spaced apart from one another in parallel and spaced apart from the at least two receiving grooves, wherein the plurality of rim holes extend perpendicular to and between the at least two receiving grooves; the plate further including a plurality of intermediate regions respectively interposed between the plurality of rim holes, wherein the plurality of intermediate regions are arranged in the plane and spaced apart from the respective groove base of the at least two receiving grooves in parallel by a height difference; at least two ramps associated with a corresponding one of the plurality of intermediate regions, wherein the at least two ramps extend between the corresponding one of the plurality of intermediate regions and the respective groove base of the at least two receiving grooves, and wherein the at least two ramps extend parallel to a longitudinal direction of the plurality of rim holes and are arranged spaced apart from one another in parallel; a seal extending in the at least two receiving grooves, wherein the seal includes an encircling sealing cord and a seal web, wherein the seal web extends over at least one of the plurality of intermediate regions and the at least two ramps; wherein the at least two ramps are rounded with a first radius at a transition to the at least two receiving grooves and with a second radius at a transition to the corresponding one of the plurality of intermediate regions, and wherein the at least two ramps have a curved profile with an inflection point arranged in a region of 10% to 80% of the height difference from the respective groove base of the at least two receiving grooves to the corresponding one of the plurality of intermediate regions.

19. The heat exchanger as claimed in claim 18, further comprising a side part insertable through at least one of the plurality of rim holes, wherein the side part includes a side part protrusion for connecting the plate to the cover, and wherein an average spacing between the side part and an adjacent outer flat tube has a value, and a ratio of the side part protrusion to the valve value of the average spacing is between 0.3 and 0.7.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings, in each case schematically:

(2) FIG. 1 is a sectional illustration through a heat exchanger having a cover, a plate and a seal according to the prior art,

(3) FIG. 2 shows a view from above of a plate according to the invention,

(4) FIG. 3 is a sectional illustration, in the section plane A-A, through the plate as per FIG. 2 in the region of a receiving groove, a ramp and an intermediate region,

(5) FIG. 4 shows a diagram illustrating the pressing force FD of the seal as a function of the angle of the ramp,

(6) FIG. 5 is an illustration as in FIG. 3, but in the case of a ramp of S-shaped form,

(7) FIG. 6 shows a diagram illustrating possible leakage L as a function of a radius R1 or R2 at the transition of the ramp to the receiving groove or to the intermediate region relative to the radius R3 of the seal,

(8) FIG. 7 shows a view from above of the plate according to the invention for the purposes of illustrating a spacing a between a longitudinal end of a rim hole and the transition of the ramp to the intermediate region,

(9) FIG. 8 shows a diagram illustrating the dependence of the tube stress .sub.R on the spacing a,

(10) FIG. 9 shows a view from above of the plate according to the invention for the purposes of illustrating the width b1 of the ramp and the width b2 of the intermediate region,

(11) FIG. 10 shows a view from above, and a sectional illustration, of the seal belonging to the plate according to the invention, for the purposes of illustrating the profile of the seal with seal web and preload webs,

(12) FIG. 11 is a sectional illustration through the heat exchanger according to the invention for the purposes of illustrating the protrusion s of a side wall and the spacings of the individual flat tubes to one another and of an outer flat tube to the side wall,

(13) FIG. 12 shows a diagram for illustrating the strength of the flanged connection realized by way of the bent-over protrusion s, as a function of a ratio s/q,

(14) FIG. 13 is a sectional illustration through the heat exchanger according to the invention with lateral protrusion for the fixing of the cover to the plate.

DETAILED DESCRIPTION

(15) Correspondingly to FIGS. 1 and 11, a heat exchanger 1 has a plate 2, a seal 3 and a cover 4. Here, FIG. 1 shows a heat exchanger 1 according to the prior art, whereas FIG. 11 illustrates a heat exchanger 1 according to the invention. Considering the plate 2, it can be seen that said plate has two parallel receiving grooves 5, 5 which are spaced apart from one another in parallel and extend in a longitudinal direction of the plate 2 and are arranged on two mutually opposite sides of the plate 2 and are designed to receive lateral projections 6, that is to say the box foot 15, of the cover 4. Here, each of the receiving grooves 5, 5 has a groove base 7, 7. Furthermore, the plate 2 has at least three rim holes 8, which are arranged in a plane so as to be spaced apart from one another in parallel and so as to be spaced apart from the receiving grooves 5, 5 and extend perpendicular to and between the receiving grooves 5, 5 (cf. in particular also FIGS. 2, 7, 9 and 11). Flat tubes 9 are led sealingly through the rim holes 8, wherein in each case one side part 19 is inserted through the two outer rim holes. In the plane, between two rim holes 8, there is formed an intermediate region 10 which is arranged so as to be spaced apart from the groove bases 7, 7 of the receiving grooves 5, 5 in parallel by a height difference h (cf. FIGS. 3 and 5). Furthermore, between each intermediate region 10 and the groove bases 7, 7, parallel to the longitudinal direction of the rim holes 8, there runs in each case one ramp 11, wherein the ramps 11 of adjacent intermediate regions 10 are spaced apart from one another in parallel. The seal 3 is in the form of an encircling sealing cord.

(16) According to the invention, the seal 3 now runs in the receiving grooves 5, 5 and with in each case one seal web 12 (cf. FIG. 10) over two ramps 11 and the interposed intermediate region 10, wherein, according to the invention, the ramps 11 are inclined relative to the intermediate region 10, and commonly also relative to the horizontal, by an angle of between 20 and 65 (cf. FIG. 3) or have an S-shaped profile (cf. FIG. 5), wherein an inflection point W is arranged in the region of 10% to 80% of the height difference h proceeding from the groove base 7, 7 of the receiving groove 5, 5. Here, in FIG. 3, the plate 2 has been cut away in order to illustrate the radius R2, but self-evidently does not have an opening in said region. Each of the ramps 11 is in this case rounded with a radius R1 at the transition to the receiving groove 5, 5 and with a radius R2 at the transition to the intermediate region 10. The radii R1 and R2 may self-evidently be different sizes, wherein larger radii assist in reducing the stress peaks acting on the seal 3. By way of an angle of less than 20, it is possible for disadvantages firstly in the subsequent process of deformation of the rim hole 8, and secondly in the lateral guidance of the seal 3 along the receiving groove 5, 5, to be reduced. In the case of an angle of greater than 65, the pressing force FD exerted on the seal 3 by the cover 4 would be too low, as illustrated by FIG. 4. In the angle range 20<<65 established by way of tests, an optimum pressing force FD can be achieved, by way of which the desired sealing action can be ensured. The stated height range of the inflection point W between 10 and 80% of the height difference h would yield radii R1 and R2 which are particularly expedient for the abutment of the seal 3 against the plate 2. Below and above said stated range, radii R1 and R2 have been obtained which would have an adverse effect on the width of the plate 2 and thus on the structural space requirement. It is furthermore particularly advantageous that the plate 2 according to the invention can now be produced as an endless metal sheet, and it is thus possible for heat exchangers 1 of a wide variety of sizes to be produced in a highly flexible manner.

(17) In an advantageous refinement of the solution according to the invention, a ratio of the height difference h to the diameter D of a section of the seal 3 in the receiving groove 5, 5 in the non-compressed state amounts to 0.7<h/D<2.5, preferably 1.0<h/D<2.0. By way of the ratio of h to D selected in said range, a strength advantage can be achieved by way of the resulting plate geometry.

(18) It is likewise advantageous if a ratio of the radius R1 or R2 to a radius R3 of the section of the seal 3 in the receiving groove 5, 5 in the compressed state amounts to 0.3<R1/R3<3.0 or 0.3<R2/R3<3.0. A lower ratio could, under some circumstances, lead to a leak owing to too low a contact pressure at the transition region between the receiving groove 5, 5 and the ramp 11. If the ratio is too high, this results in too low a pressing force along the ramp 11 and/or in a structural space disadvantage, because a wider plate 2 is required. Here, in FIG. 6, the leak (leakage L) is illustrated as a function of the stated radii ratio, wherein it can be clearly seen that, in the case of a radii ratio R1/R3 or R2/R3 of between 0.3 and 3.0, the leakage, that is to say the leak, is at its smallest.

(19) Furthermore, in order to be able to keep the mechanical stresses .sub.R in the flat tube 9 as low as possible, a longitudinal end, facing toward the receiving groove 5, 5, of a rim hole 8 lies between 1 mm<a<15 mm, in particular between 2 mm<a<6 mm, closer to the receiving groove 5, 5 than a transition of the ramp 11 to the intermediate region 10. The meaning of the spacing a is in this case illustrated in FIG. 7, wherein a dependency of the tube stress R on the spacing a is indicated in the diagram in FIG. 8. It can be clearly seen here that the tube stress R can be minimized in the case of a value a of between 2 and 6 mm.

(20) At least one of the ramps 11 may furthermore be formed as a groove 13 which extends parallel to the longitudinal direction of the rim holes 8 and in which the seal 3 runs in sections, wherein the ratio of the degree of groove filling by the seal 3 in the groove 13 to the degree of groove filling by the seal 3 in the receiving groove 5, 5 in the compressed state of the seal 3 should amount to between 1.0 and 1.4. If the ratio lies in the stated range, the seal 3 can, on the one hand, be optimally guided and fixed, and secondly, an optimum sealing function can be achieved by way of more intense compression in the ramp region 11 and/or in the transition region of the ramp 11 to the receiving groove 5, 5 and/or to the intermediate region 10.

(21) Considering FIG. 9, it can be seen that the ramps 11 have a width b1 and the intermediate regions 10 have a width b2, wherein the ratio of the width b1 to b2 should amount to between 0.3 and 1.0. Furthermore, the cross section of the seal 3 in the region of the ramp 11 should amount to >40% of the cross section of the seal 3 in the region of the receiving groove 5, 5, preferably between 50% and 70%. In this way, an optimum degree of groove filling can be achieved by way of simple structural means.

(22) Considering FIG. 10, it can be seen that the seal 3 has, in addition to the seal web 12 itself, at least one further preload web 14 which runs parallel to the seal web 12 and which effects a reduction of tensile stress on the seal 3. In this way, it is possible for the desired optimum position required for the sealing action to be ensured both along the receiving groove 5, 5 and between the rim holes 8.

(23) Considering FIG. 13, it is shown in said Figure that the cover 4 has lateral projections 6, or box feet 15, running along the longitudinal side at two mutually opposite sides, wherein, in the situation shown, only one of the two sides is illustrated, and wherein the lateral projections 6 extend in the receiving grooves 5, 5 and have a protrusion 16 which projects longitudinally beyond the respective receiving groove 5, 5. The protrusion 16 is intended to project beyond the region at which the seal 3 bends. Here, said seal may also project beyond the receiving groove 5, 5 or else terminate flush therewith. Owing to the position of the seal 3 between the rim holes 8 in the region of a narrow side, it is advantageous, for the sealing compression of the seal 3, if the connection between the plate 2 and the cover 4 extends along the receiving groove 5, 5 at least to the point where the seal 3 is led between the rim holes 8, particularly advantageous if the box foot 15 projects along the receiving groove 5, 5 beyond the seal 3, wherein said box foot may form a flush termination of the respective receiving groove 5, 5 or has the protrusion 16 described above. In this case, too, the protrusion 16 should project beyond the region at which the seal 3 bends.

(24) This gives rise to a H-shaped lateral projection design. FIG. 13 shows such a connection of the cover 4 to the plate 2, wherein the profile of the seal 3 and the position of an outer closure 17, which extends, through the likewise illustrated protrusion 16 on the box foot 15, beyond the profile of the seal 3 between the rim holes 8 are shown. In this way, an improved sealing function is possible in particular by way of a greater pressing action.

(25) It may also be provided that, on the box foot 15, there is arranged a projection 20 for the positioning of the cover 4 on the plate 2. A projection 20 of said type serves for the optimum positioning of the cover 4 relative to the plate 2 in a longitudinal direction, and furthermore makes it possible for the tolerances of the tolerance chain in the longitudinal direction to be halved.

(26) The receiving groove 5, 5 may furthermore have a wall 18 which, for the connection of the cover 4 to the plate 2, is at least partially bent, specifically in such a way that it engages behind a part of the box foot 15 of the cover 4. The wall 18 of the receiving groove 5, 5 may have multiple regions and/or crenellations which repeat in terms of their geometrical shape and which are arranged symmetrically with respect to the rim holes 8 of the plate 2 and which can be or are bent around the box foot 15 of the cover 4 (cf. FIG. 1). Furthermore, the heat exchanger 1 has a side part 19 with a side part protrusion s for the connection of the plate 2 to the cover 4, wherein the average spacing between the side part 19 and an adjacent, outer flat tube 9 has the value q, and wherein the ratio s/q should amount to between 0.3 and 0.7 (cf. FIGS. 11 and 12). Here, in FIG. 11, a combination with a side part protrusion s is shown, wherein the ratio s/q is in this case 0.7. In the case of a ratio s/q=0.3, a smaller contact surface against the lateral projection 6 or box foot 15 is realized. The side part protrusion s should therefore be selected such that, on the one hand, the pressing force required for the sealed connection between the plate 2 and the cover 4 can be achieved, but the cover 4 does not impede a flow in the outermost flat tube 9. Here, FIG. 12 shows the strength of the closure and thus also indirectly the sealing action as a function of the ratio s/q.

(27) All of the rim holes 8 of the plate 2 may have the same contour and the same area for tubes 9 and side parts 19, whereby the manufacturing process is simplified. It is also possible for the outer rim holes 8 to have, depending on the wall thickness of the side part 19, a smaller or larger area than the other rim holes 8.

(28) Furthermore, the shape of the transition regions, in particular between the two outer rim holes 8, may differ from that of the other transition regions. For example, the ramp 11 may be implemented only between the outer three rim holes 8. The shape of the transition regions may also differ so as to yield a repeating pattern.

(29) With the heat exchanger 1 according to the invention, and in particular with a plate 2 according to the invention, it is possible for a plate 2 of said type to be produced as an endless metal sheet and thus to be used in a highly flexible manner in heat exchangers 1 of different dimensions. At the same time, an optimum sealing action can be achieved.