Heat exchanger

Abstract

A heat exchanger may include an outer casing extending in a longitudinal direction and delimiting a volume through which a first fluid is flowable, and a tube bundle including a plurality of tube bodies arranged in the volume and through which a second fluid is flowable. In a cross section, the volume may have an inner surface area and an inner circumference and each tube body may have an outer circumference and an outer surface area. A ratio of a sum of the outer circumferences to the inner circumference may be at least 5.5, and a sum of the outer surface areas may account for 64% or less of the inner surface area. A residual cross section area of the inner surface area may be delimited between the outer casing and the plurality of tube bodies.

Claims

1. A heat exchanger, comprising: an outer casing extending in a longitudinal direction and delimiting a volume through which a first fluid is flowable in the longitudinal direction during operation; a width direction extending transversely to the longitudinal direction; a height direction extending transversely to the longitudinal direction and transversely to the width direction; a tube bundle including a plurality of tube bodies through which a second fluid is flowable in the longitudinal direction during operation, the plurality of tube bodies arranged in the volume and extending in the longitudinal direction, the second fluid fluidically separated from the first fluid; wherein, in a cross section defined by the width direction and the height direction, the volume has an inner surface area and an inner circumference and each tube body of the plurality of tube bodies has an outer circumference and an outer surface area; wherein, in at least one portion of the volume extending in the longitudinal direction, at least one of: a ratio of a sum of the outer circumference of each of the plurality of tube bodies to the inner circumference is at least 5.5; and a sum of the outer surface area of each of the plurality of tube bodies accounts for 64% or less of the inner surface area; wherein a residual cross section area of the inner surface area, through which the first fluid is flowable during operation, is delimited between the outer casing and the plurality of tube bodies.

2. The heat exchanger according to claim 1, wherein the plurality of tube bodies are each structured as a flat tube.

3. The heat exchanger according to claim 1, wherein: each tube body of at least one subset of the plurality of tube bodies in the at least one portion of the volume have a tube height extending in the height direction; and the tube height corresponds to 4.80% to 6.90% of a surface height of the inner surface area that extends in the height direction.

4. The heat exchanger according to claim 1, wherein: each tube body of at least one subset of the plurality of tube bodies in the at least one portion of the volume have a tube width extending in the width direction; and the tube width corresponds to 24.00% to 24.90% of a surface width of the inner surface area that extends in the width direction.

5. The heat exchanger according to claim 1, wherein: each tube body of the plurality of tube bodies is disposed a width distance from each laterally adjacent tube body of the plurality of tube bodies; and in at least one subset of the plurality of tube bodies in the at least one portion of the volume, the width distance corresponds to 2.00% to 3.00% of a surface width of the inner surface area that extends in the width direction.

6. The heat exchanger according to claim 1, wherein: each tube body of the plurality of tube bodies is disposed a height distance from each vertically adjacent tube body of the plurality of tube bodies; and in at least one subset of the plurality of tube bodies in the at least one portion of the volume, the height distance corresponds to 1.80% to 2.30% of a surface height of the inner surface area that extends in the height direction.

7. The heat exchanger according to claim 1, wherein each tube body of at least one subset of the plurality of tube bodies in the at least one portion of the volume have a wall thickness that corresponds to 0.48% to 0.56% of a surface width of the inner surface area that extends in the width direction.

8. The heat exchanger according to claim 1, wherein the tube bundle includes a plurality of rows of the plurality of tube bodies, the plurality of rows extending in the width direction and disposed spaced apart from one another in the height direction.

9. The heat exchanger according to claim 8, wherein each row of the plurality of rows includes 3 to 5 tube bodies of the plurality of tube bodies.

10. The heat exchanger according to claim 1, wherein at least one tube body of the plurality of tube bodies is structured as a winglet tube body including a plurality of elements protruding into the at least one tube body.

11. The heat exchanger according to claim 1, wherein each tube body of at least one subset of the plurality of tube bodies in the at least one portion of the volume have a wall thickness that corresponds to 0.43% to 0.50% of a surface height of the inner surface area that extends in the height direction.

12. The heat exchanger according to claim 1, wherein the tube bundle includes a plurality of columns of the plurality of tube bodies, the plurality of columns extending in the height direction and disposed spaced apart from one another in the width direction.

13. The heat exchanger according to claim 12, wherein each column of the plurality of columns includes 9 to 14 tube bodies of the plurality of tube bodies.

14. A heat exchanger, comprising: an outer casing extending in a longitudinal direction and delimiting a volume through which a first fluid is flowable in the longitudinal direction during operation; a width direction extending transversely to the longitudinal direction; a height direction extending transversely to the longitudinal direction and transversely to the width direction; a tube bundle including a plurality of tube bodies through which a second fluid is flowable in the longitudinal direction during operation, the plurality of tube bodies arranged in a plurality of rows and a plurality of columns within the volume and extending in the longitudinal direction, the second fluid fluidically separated from the first fluid; wherein, in a cross section defined by the width direction and the height direction, the volume has an inner circumference surrounding an inner surface area and each tube body of the plurality of tube bodies has an outer circumference surrounding an outer surface area; wherein, at least one of: a ratio of a sum of the outer circumference of each of the plurality of tube bodies to the inner circumference is at least 5.5; and a sum of the outer surface area of each of the plurality of tube bodies accounts for 64% or less of the inner surface area; wherein a residual cross section area of the inner surface area, through which the first fluid is flowable during operation, is delimited between the outer casing and the plurality of tube bodies.

15. The heat exchanger according to claim 14, wherein: the plurality of tubes bodies of each row of the plurality of rows are disposed a width distance from one another; and the width distance corresponds to 2.00% to 3.00% of a surface width of the inner surface area that extends in the width direction.

16. The heat exchanger according to claim 14, wherein: the plurality of tubes bodies of each column of the plurality of columns are disposed a height distance from one another; and the height distance corresponds to 1.80% to 2.30% of a surface height of the inner surface area that extends in the height direction.

17. A heat exchanger, comprising: a longitudinal direction, a width direction extending transversely to the longitudinal direction, and a height direction extending transversely to the longitudinal direction and transversely to the width direction; an outer casing extending in the longitudinal direction and delimiting a volume through which a first fluid is flowable during operation; a tube bundle including a plurality of flat tube bodies through which a second fluid is flowable during operation, the plurality of tube bodies arranged within the volume and extending in the longitudinal direction; wherein, in a cross section defined by the width direction and the height direction, the volume has an inner circumference surrounding an inner surface area and each tube body of the plurality of tube bodies has an outer circumference surrounding an outer surface area; wherein a ratio of a sum of the outer circumference of each of the plurality of tube bodies to the inner circumference is at least 5.5; and wherein a residual cross section area of the inner surface area is delimited between the outer casing and the plurality of tube bodies, the residual cross section area defining a through flow area of the first fluid during operation.

18. The heat exchanger according to claim 17, wherein a sum of the outer surface area of each of the plurality of tube bodies accounts for 64% or less of the inner surface area.

19. The heat exchanger according to claim 17, wherein: each tube body of the plurality of tube bodies have a tube height extending in the height direction; and the tube height corresponds to 4.80% to 6.90% of a surface height of the inner surface area that extends in the height direction.

20. The heat exchanger according to claim 17, wherein: each tube body of the plurality of tube bodies have a tube width extending in the width direction; and the tube width corresponds to 24.00% to 24.90% of a surface width of the inner surface area that extends in the width direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) It shows, in each case schematically

(2) FIG. 1 shows an isometric view of a heat exchanger,

(3) FIG. 2 shows a section through the heat exchanger,

(4) FIG. 3 shows an isometric view of a tube body of the heat exchanger,

(5) FIG. 4 shows the view from FIG. 2 with another exemplary embodiment,

(6) FIG. 5 shows the view from FIG. 2 with a further exemplary embodiment,

(7) FIG. 6 shows a section through the tube body with another exemplary embodiment.

DETAILED DESCRIPTION

(8) A heat exchanger 1, as shown in FIG. 1, comprises an outer casing 2, which extends in a longitudinal direction 3, a width direction 4 running transversely to the longitudinal direction 3 and a height direction 5 running transversely to the longitudinal direction 3 and transversely to the width direction 4. Here, the outer casing 2 delimits a volume 6 which during the operation of the heat exchanger 1 is flowed through by a first fluid, in particular in the longitudinal direction 3. On longitudinal end sides 7 of the heat exchanger 1 facing away from one another, an inlet opening 8 and an outlet opening 9 are provided in the shown example, through which the first fluid flows during the operation. In addition, a second fluid, separated from the first fluid, additionally flows through the heat exchanger 1 during the operation, which is brought into the volume 6 and out of the volume 6 via corresponding supply openings 10, so that during the operation of the heat exchanger 1 a heat exchange between the first fluid and the second fluid occurs. The first fluid can be exhaust gas while the second fluid is a coolant, so that during the operation of the heat exchanger a cooling of the exhaust gas occurs, so that the heat exchanger 1 is configured as an exhaust gas heat exchanger 11.

(9) The FIGS. 2, 4 and 5 each show a cross section 12 through the outer casing 2 of the heat exchanger 1 with a different exemplary embodiment each, wherein the respective cross section 12 is defined by the width direction 4 and the height direction 5. Accordingly, the heat exchanger 1 comprises a tube bundle 13 with multiple tube bodies 14, which extend through the volume 6 in the longitudinal direction. During the operation, the first fluid, i.e. in particular exhaust gas, flows through the tube body 14 of the tube bundle 13. In the shown examples, the tube bodies 14 are each identical and in each case formed as a flat tube 15. In the respective cross section, the volume 6 has an inner surface 16 delimited by the outer casing 2 and an inner circumference 17 defined by the outer casing 2. In the shown examples, the outer casing 2 and thus the volume 6 is formed rectangular in the cross section 12, so that the inner circumference 17 is formed by twice the sum of a surface width 18 of the inner surface 16 running in the width direction 4 and a surface height 9 of the inner surface 16 running in the height direction 5. In addition, the inner surface 16 corresponds to the product of surface width 18 and surface height 19.

(10) In FIG. 3, one of the tube bodies 14 is exemplarily shown. The respective tube body 14 has an outer width 20 running in the width direction 4, also called tube width 20 in the following, and an outer height 21 running in the height direction 5, also called tube height 21 in the following. In addition, the respective tube body 14 has a wall thickness 22 of a wall 23, which delimits a space 34 of the tube body 14 that can be flowed through in the longitudinal direction 3. The tube bodies 14 formed as flat tubes 15 have a tube width 20 in the shown examples, which is greater than the tube height 21. Thus, the respective tube body 14 in the respective cross section 12 has an outer circumference 24 and an outer surface 25, wherein the outer circumference 24 with a rectangular cross section of the respective tube body 14 corresponds to twice the sum of tube width 20 and tube height 21 and the outer surface 25 to the product of tube width 20 and tube height 21.

(11) According to the invention it is provided that in at least one portion of the volume 6 running in the longitudinal direction 3, preferentially along the entire tube bundle 13, the sum of the outer circumferences 24 of all tube bodies in each cross section 12 is at least 5.5 times greater than the associated inner circumference 17 of the volume 6 in the associated cross section 12 and/or that in the said portion in each cross section 12 the inner surface 16 of the volume 6 is maximally filled to 64% of the sum of all outer surfaces 25 of the tube bodies 14 in the associated cross section 12, namely in each case in such a manner that the tube bodies 14 delimit a residual cross section of the inner surface 16 flowed through by the first fluid during the operation. In the sum, the outer surfaces 25 of the tube bodies 14 define a heat-exchanging total outer surface of the tube bundle 13, which in the respective cross section 12 and thus in the said portion is optimised, in particular maximised, wherein an adequate residual cross section of the cross section 12 remains in order to optimise the through-flow of the first fluid and/or in order to reduce the weight of the tube bundle 13 and thus of the heat exchanger 1.

(12) In the shown examples, as mentioned above, the tube bodies 14 are each formed identically and as flat tube 15. In addition, the respective tube bundle 13 comprises tube bodies 14 following one another in the width direction 4 and arranged at a width distance 26 relative to one another, and tube bodies 14 which are arranged next to one another in the height direction 5 having a height distance 27 relative to one another. In the shown examples, the tube bodies 14 following one another in the width direction 4 have a same width distance 26, are thus arranged equidistantly in the width direction 4. Thus, the tube bundle 13 comprises multiple rows 28 running in the width direction 4 and spaced apart in the height direction relative to one another, in particular by the height distance 27, and multiple columns 29 of tube bodies 14 running in the height direction 5 and in the width direction 4, which are in particular spaced apart relative to one another by the width distance 26. In the shown examples, the tube bodies 14 following one another in the height direction 5 have a same height distance 27, are thus arranged equidistantly in the height direction 5.

(13) In the shown examples, the tube height 21 of the respective tube body 14 corresponds to between 4.80% and 6.90% of the surface height 19 in the associated cross section 12. Alternatively or additionally, the tube width 20 of the respective tube body 14 amounts to between 24.00% and 24.90% of the surface width 18 in the associated cross section 12. Alternatively or additionally it can be provided that the width distance 25 of the tube bodies 14 relative to one another corresponds to between 2.00% and 3.00% of the surface width 18 in the associated cross section 12. The height distance 27 of the tube bodies 14 relative to one another can also correspond to between 1.80% and 2.30% of the surface height 19 in the associated cross section 12. It is conceivable, in particular, that the wall thickness 22 of the respective tube body 14 corresponds to between 0.48% and 056% of the surface width 18 and/or to between 0.43% and 0.50% of the associated surface height 19 in the associated cross section 12.

(14) Here, the volume 6 can have any surface width 18 and surface height 19. In particular, the surface width 18 can amount to between 50.00 mm and 60.00 mm, for example 55.5 mm. The surface height 19 can amount to between 55.0 and 65.0 mm, for example 61.5 mm. In the following it is assumed purely exemplarily and for comparative purposes that the surface width 18 amounts to 55.5 mm and the surface height 19 to 61.5 mm. In addition, as explained above, it is assumed for the purpose of an easier comparison that the respective cross section 12 and the respective tube body 14 are formed rectangularly in the cross section 12, even when the respective tube body 14, as visible in FIG. 3, can have rounded corners.

(15) As mentioned, the FIGS. 2, 4 and 5 each show a cross section 12 through the outer casing of the heat exchanger 1 with different exemplary embodiment each. Preferably, the remaining cross sections 12 in the said portion of the respective exemplary embodiment which are not shown are configured corresponding to the shown cross section 12 of the associated exemplary embodiment. In other words, all cross sections 12 in the portion of the respective exemplary embodiment are preferably configured like the shown cross section 12 of the exemplary embodiment.

(16) In the example shown in FIG. 2, four columns 29 and ten rows 28 of the tube bodies 14 and thus forty tube bodies 14 in total are provided. The tube bundle 14 thus comprises forty tube bodies 14, which are each formed identically. The respective tube body 14 has a tube width 20 of 24.32% of the surface width 18, in the assumed example thus a tube width 20 of 13.5 mm. In addition, the respective tube body 14 has a tube height 21, which corresponds to 6.34% of the surface height 19, thus in the assumed example 3.9 mm. Accordingly, the sum of the outer circumferences 24 of the tube bodies 14 is 5.94 times greater than the inner circumference 17 of the volume 6 in the respective cross section 12 of the said portion. In addition to this, the sum of the outer surfaces 25 of the tube bodies 14 amounts to 61.7% of the inner surface 16 of the volume 6. In addition, the width distance 26 of the tube bodies 14 each amounts to 2.70% of the surface width 18, thus in particular 1.5 mm. The height distance 27 of the tube bodies 14 amounts to 2.44% of the surface height 19 or likewise 1.5 mm.

(17) In the example shown in FIG. 4, the tube bundle 13 comprises four rows 28 and eleven columns 29 of the tube bodies 14. Thus, the tube bundle 13 comprises forty-four tube bodies 14 in total. The respective tube body 14 has a tube width 20 which amounts to 24.50% of the surface width 18, thus in the assumed example 13.6 mm. In addition, the respective tube body 14 has a tube height 21 which corresponds to 5.69% of the surface height 19, thus in the assumed example 3.5 mm. Thus, the sum of the outer circumferences 24 of the tube bodies 14 amounts to 6.43 times the inner circumference 17. In addition to this, the inner surface 16 is filled to 61.36% by the sum of the outer surfaces 25 of the tube body 14 and thus by the tube bundle 13. The width distance 26 amounts to 2.56% of the surface width 18, thus in the assumed example 1.42 mm. The height distance 27 corresponds to the width distance 26, thus in the assumed example 1.42 mm or 2.31% of the surface height 19.

(18) In the example shown in FIG. 5, the tube bundle 13 comprises twelve rows 28 and four columns 29 of tube bodies 14 and thus forty-eight tube bodies 14 in total. The tube width 20 of the respective tube body 14 corresponds to 24.77% of the surface width 18, thus in the assumed example to 13.75 mm. The tube height 21 of the respective tube body 14 corresponds to 5.24% of the surface height 19, thus in the assumed example to 3.22 mm. The width distance 26 of the tube body 14 corresponds to 2.34% of the surface width 18, thus in the assumed example to 1.3 mm. The height distance 27 corresponds to the width distance 26 and thus to 2.11% of the surface height 19, in the assumed example thus likewise to 1.3 mm. The sum of the outer circumferences 24 of all tube bodies 14 consequently amounts to 6.96 times the inner circumference 17, while the outer surfaces 25 of all tube bodies 14 and thus of the tube bundle 13 fill the inner surface 16 to 62.26%.

(19) In FIG. 6, a further exemplary embodiment of a tube body 14, which is likewise formed as a flat tube 15, is shown in section. This tube body 14 is formed as a so-called winglet tube 30 and comprises elements 31, so-called winglets 32, projecting on the inside. In this example, the winglets 32 are moulded towards the inside in the wall 23 of the tube body 14. In addition, the tube body 14 comprises elements 31 projecting to the outside in the form of nubs 33, which in particular can serve the purpose of spacing the neighbouring tube bodies 14 apart relative to one another. The elements 31 projecting to the outside are also formed by a moulding of the wall 23 in the shown example. In FIG. 3 it is illustrated that in such cases the tube width 20 and the tube height 21 relate to the state of the tube body 14 prior to the deformation, so that the elements 31 projecting to the inside and projecting to the outside are not taken into account.

(20) In the respective example, the wall thickness 22 of the tube bodies 14 corresponds to between 0.48% and 0.56% of the surface width 18 or to between 0.43% and 0.05% of the associated surface height 19. In particular, the wall thickness amounts to between 0.28 mm and 0.3 mm.

(21) In all shown examples, an optimisation of the tube bundle 13 as a whole in the available cross section 12, in particular the available volume 6, takes place for increasing the total outer surface of the tube bundle 13 with simultaneous reduction of the weight of the tube bundle 13 and optimisation of the residual cross section. This optimisation increases from the exemplary embodiment 2 shown in FIG. 2 to the exemplary embodiment shown in FIG. 4 and further to the exemplary embodiment shown in FIG. 5.