Abstract
A flat tube for a heat exchanger may include a longitudinal-end inlet for letting a fluid into the flat tube, and a longitudinal-end outlet spaced apart from the inlet in a longitudinal direction for letting the fluid out from the flat tube. The flat tube may also include flow elements around at least a portion of which the fluid may be flowable around the flow elements in such a manner that the fluid may have a flow direction component perpendicular to the longitudinal direction. The outlet and the inlet each may be delimited on a partial cross-sectional area of the flat tube and arranged diagonally opposite one another.
Claims
1. A flat tube for a heat exchanger, comprising: a longitudinal-end inlet for letting a fluid into the flat tube; a longitudinal-end outlet spaced apart from the inlet in a longitudinal direction for letting the fluid out from the flat tube; and flow elements around at least a portion of which the fluid is flowable around the flow elements in such a manner that the fluid has a flow direction component perpendicular to the longitudinal direction; wherein the outlet and the inlet are each delimited on a partial cross-sectional area of the flat tube and are arranged diagonally opposite one another.
2. The flat tube according to claim 1, further comprising: an inlet section running in a transverse direction transverse to the longitudinal direction, the inlet section containing the inlet; an outlet section running in the transverse direction and containing the outlet; and a heat exchange section arranged in the transverse direction between the inlet section and the outlet section, the flow elements being arranged in the heat exchange section.
3. The flat tube according to claim 2, wherein at least one of: a cross-section of the inlet section decreases in the longitudinal direction towards the outlet; and a cross-section of the outlet section decreases in the longitudinal direction towards the inlet.
4. The flat tube according to claim 3, wherein at least one of the inlet section and the outlet section runs in a wedge shape in the longitudinal direction.
5. The flat tube according to claim 2, wherein the heat exchange section runs obliquely in the longitudinal direction.
6. The flat tube according to claim 1, wherein the flow elements are arranged in at least two lines spaced apart in the longitudinal direction, wherein each line has at least two flow elements spaced apart in a transverse direction transverse to the longitudinal direction.
7. The flat tube according to claim 6, wherein the flow elements of one line are arranged offset in the transverse direction to the flow elements in an adjacent line.
8. The flat tube according to claim 1, wherein the flow elements are at least partially combined in a turbulence insert formed separately from a body of the flat tube.
9. The flat tube according to claim 1, wherein at least one flow element is formed as an inwardly directed deformation of a body of the flat tube.
10. The flat tube according to claim 9, wherein at least one flow element configured as an inwardly directed deformation touches an opposite wall of the body of the flat tube.
11. The flat tube according to claim 1, wherein at least one flow element includes a porous material.
12. The flat tube according to claim 1, wherein the flow elements are arranged such that the fluid is flowable in the flat tube in a diagonal meander-shaped.
13. A heat exchanger comprising: two opposite collectors; at least two flat tubes arranged between the two opposite collectors, each flat tube including: a longitudinal-end inlet for letting a fluid into the flat tube; a longitudinal-end outlet spaced apart from the inlet in a longitudinal direction for letting the fluid out from the flat tube; and flow elements around at least a portion of which the fluid is flowable around the flow elements in such a manner that the fluid has a flow direction component perpendicular to the longitudinal direction; the outlet and the inlet each being delimited on a partial cross-sectional area of the flat tube and arranged diagonally opposite one another; wherein a first fluid flows in the flat tubes and the collectors, and the second fluid flows around the flat tubes.
14. The heat exchanger according to claim 13, wherein a flow through the heat exchanger takes place in a cross-counter-flow.
15. The heat exchanger according to claim 13, further comprising a first inlet collector and a second inlet collector, and an outlet collector is arranged therebetween the inlet collectors, and at least one flat tube is arranged between each inlet collector and the outlet collector.
16. The heat exchanger according to claim 15, wherein at least one flat tube between the first inlet collector and the outlet collector and at least one flat tube between the second inlet collector and the outlet collector are arranged inclined to one another.
17. The flat tube according to claim 9, wherein the inwardly directed deformation is at least one of an embossing and a dimple.
18. The flat tube according to claim 11, wherein the porous material is a metal foam.
19. The heat exchanger according to claim 16, wherein the at least one flat tube between the first inlet collector and the outlet collector and the at least one flat tube between the second inlet collector and the outlet collector are arranged transversely to one another.
20. A flat tube for a heat exchanger, comprising: an inlet section running in a first direction containing an inlet for letting a fluid into the flat tube; an outlet section running in the first direction and containing an outlet for letting the fluid out from the flat tube, the outlet being spaced apart from the inlet in a second direction transverse to the first direction; a heat exchange section arranged in the first direction between the inlet section and the outlet section; and a plurality of flow elements arranged in the heat exchange section; wherein the fluid is flowable around at least a portion of the flow elements in such a manner that the fluid has a flow direction component perpendicular to the second direction; wherein the outlet and the inlet are each delimited on a partial cross-sectional area of the flat tube and are arranged diagonally opposite one another; and wherein the flow elements are arranged in at least two lines spaced apart in the second direction, each line having at least two flow elements spaced apart in the first direction.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] In the figures, in each case schematically
[0039] FIG. 1 shows a spatial view of a flat tube,
[0040] FIG. 2 shows a section through a heat exchanger in the area of the flat tube in another exemplary embodiment of the flat tube, wherein the flat tube is shown partially cutaway,
[0041] FIG. 3 shows the view from FIG. 2 in a further exemplary embodiment of the flat tube,
[0042] FIGS. 4 to 6 each shows a longitudinal section through the heat exchanger in respectively different exemplary embodiments.
DETAILED DESCRIPTION
[0043] According to FIG. 1, the flat tube 1 has two longitudinal end sides 8 along a longitudinal direction 2, wherein an inlet 3 is arranged on one of the longitudinal end sides 8 and an outlet 4 is arranged on the opposite longitudinal end side 8. Inlet 3 and outlet 4 are used to let a first fluid into the flat tube 1 or to let the first fluid out of the flat tube 1. Inlet 3 and outlet 4 are in this case delimited to a partial cross-sectional area of the flat tube 1 and are arranged offset with respect to one another in a transverse direction 5 running transversely to the longitudinal direction 2. The inlet 3 is arranged on a first transverse end 6 running contrary to the transverse direction 5 whilst the outlet 4 is arranged at a second transverse end 7 of the flat tube 1 in the transverse direction 5. Inlet 3 and outlet 4 are thus arranged diagonally opposite one another. In addition, the longitudinal end sides 8 of the flat tube 1 are closed and therefore the first fluid cannot flow through it. A plurality of flow elements 9 are provided in the flat tube 1 around which the first fluid can flow in such a manner that the flowing first fluid has a flow direction component perpendicular to the longitudinal direction 2 or in transverse direction 5.
[0044] The flat tube 1 is used, as shown in FIG. 2 in a heat exchanger 10, wherein the flat tube 1 is shown partially cutaway in FIG. 2. The flat tube 1 can be divided into three sub-sections 11, 12, 13 in transverse direction 5. The inlet 3 is arranged in an inlet section 11 which is arranged in the area of the first transverse end 6. The flow elements 9 are arranged in a heat exchange section 12 whereas the outlet 4 is arranged in an outlet section 13 which is arranged in the area of the second transverse end 7. The heat exchange section 12 is arranged between inlet section 11 and outlet section 13, wherein inlet section 11 and outlet section 13 are free from flow elements 9. The inlet section 11 and the outlet section 13 as well as the inlet 3 and the outlet 4 are substantially the same size whereas the heat exchange section 12 is many times larger in transverse direction 5 than the inlet section 11 and the outlet section 13, in the example shown for example five times greater than the inlet section 11 or the outlet section 13. If the first fluid, as indicated by first dashed arrows 14, flows through the inlet 3 into the flat tube 1, it initially enters into the flat tube 1 in the inlet section. As a result of the offset arrangement of the outlet 4 and the flow elements 9, the first fluid in the flat tube 1 has the flow direction component perpendicular to the longitudinal direction 2 and is therefore deflected in transverse direction 5 in the direction of the outlet section 13 and thereby passes the heat exchange section 12. The first fluid then passes through the outlet 4 in the outlet section 13 from the flat tube 1. The first fluid therefore flows both in longitudinal direction 2 and also in transverse direction 5. In the heat exchanger 10 the first fluid exchanges heat with a second fluid wherein the second fluid, as indicated by a second arrow 15, flows contrary to the transverse direction 5 through the heat exchanger 10 and flows around the flat tube 1. Consequently, the first fluid flows through the flow in longitudinal direction 2 in cross-flow to the second fluid and through the flow in transverse direction 5 contrary to the flow direction of the second fluid or in the counter-flow direction. A cross-counter-flow of the first fluid to the second fluid is therefore achieved by means of the flat tube 1. The first fluid and the second fluid thereby flow through the heat exchanger in a fluidically separated manner.
[0045] In the exemplary embodiments of the flat tube 1 shown in FIGS. 1 and 2 the flow elements 9 are grouped in lines 16. The lines 16 are spaced apart in longitudinal direction 2 and each have at least two such flow elements 9, wherein the flow elements 9 of the respective line 16 are spaced apart in transverse direction 5. In addition, the longitudinal extension of the respective flow element 9 runs in transverse direction 5. It can be further deduced from FIGS. 1 and 2 that the flow elements 9 of neighbouring lines 16 are arranged in running bond manner with respect to one another. That is that the flow elements 9 of neighbouring lines 16 in longitudinal direction 2 are arranged offset with respect to one another in transverse direction 5, wherein in the example shown the respective flow element 9 in transverse direction 5 is arranged substantially centrally between the neighbouring flow elements 9 in transverse direction 5 of the neighbouring lines 16 in longitudinal direction 2.
[0046] In the exemplary embodiment shown in FIG. 2, the flow elements 9 are each configured as an inwardly directed deformation 17, in particular an embossing 17′ of the flat tube 1 or a dimple 17″. The flow elements 9 are therefore an integral component of the flat tube 1.
[0047] Alternatively the flow elements 9, as shown in FIG. 1, can be combined in a turbulence insert 18 configured separately to the flat tube 1. The turbulence insert 18 is arranged in the flat tube 1 and connected to the flat tube 1.
[0048] FIG. 3 shows another exemplary embodiment of the flat tube 1 in the heat exchanger 10. In this exemplary embodiment the flow elements 9 are combined in columns 19 which are spaced apart from one another in transverse direction 5. The respective column 19 has flow elements 9 which are spaced apart from one another in longitudinal direction 2. The flow elements 9 of the columns 19 extend with their longitudinal extension in longitudinal direction 2. The flow elements 9 of neighbouring columns 19 in transverse direction 5 are arranged with respect to one another in the running bond in such a manner that the flow elements 9 of neighbouring columns 19 in transverse direction 5 are arranged offset with respect to one another in longitudinal direction 2. This results in a diagonal meander-shaped flow of the first fluid in the flat tube 1, as indicated by the dashed first arrows 14.
[0049] It is further deduced from FIG. 3 that the flow elements 9 are configured as such inwardly directed deformations 17, in particular as embossings 17′ or dimples 17″ of the flat tube 1. It can be further identified in FIG. 3 that the respective deformation 17 extends over at least a part of a thickness 20 of the flat tube 1 running transversely to the longitudinal direction 2 and transversely to the transverse direction 5. In the exemplary embodiment shown in FIG. 3 the opposite walls 21 of the flat tube 1 along the thickness 20 are in contact and therefore touch. In this way, a particularly effective deflection of the first fluid in transverse direction 15 and therefore a large flow direction component of the first fluid perpendicular to the longitudinal direction 2 or in transverse direction 5 is possible.
[0050] The heat exchanger 10 can naturally also have a plurality of such flat tubes 1 which each having the second fluid flowing around them.
[0051] FIG. 4 shows a longitudinal section through the heat exchanger 10 of another exemplary embodiment. It can be seen here that the heat exchange section 12 runs obliquely in longitudinal direction 2 whilst the cross-section of the inlet section 11 decreases towards the outlet in longitudinal direction 5 and vanishes or falls to zero at the longitudinal end 8 of the outlet 4. The outlet section 13 decreases in longitudinal direction 2 towards the inlet and is reduced to zero at the longitudinal end 8 of the inlet 3. The heat exchanger 10 additionally has two opposite collectors 22 23, in longitudinal direction 2, namely an inlet collector 22 for letting the first fluid into the at least one flat tube 1 and an outlet collector 23 for letting the first fluid out of the at least one flat tube 1 which are arranged spaced apart from one another in longitudinal direction 2. The fluidic communication between the flat tube 1 and the respective collector 22, 23 can be achieved, for example, by means of non-visible passages formed in a base not shown of the respective collector 22, 23.
[0052] A further exemplary embodiment of the heat exchanger 10 is shown in FIG. 5. In this exemplary embodiment the heat exchanger 10 has two such inlet collectors 22, namely a first inlet collector 22′ and a second inlet collector 22″. A common such outlet collector 23 is arranged between the inlet collectors 22, wherein the respective inlet collector 22 is fluidically connected to the outlet collector 23 by means of at least one such flat tube 1 in such a manner that at least one such flat tube 1′ runs between the first inlet collector 22′ and the outlet collector 23 and at least one such second flat tube 1″ runs between the second inlet collector 22′ and the outlet collector 23. The first flat tube 1′ and the second flat tube 1″ have a common longitudinal direction 2 or are arranged parallel. The flat tubes 1′ and 1″ here each correspond to the flat tube 1 from FIG. 4.
[0053] A further exemplary embodiment of the heat exchanger 10 is shown in FIG. 6. This exemplary embodiment differs from the exemplary embodiment shown in FIG. 5 in particular in that the first flat tube 1′ and the second flat tube 1″ are run at an inclination, in particular transversely to one another. This results in an angled, in particular L-shaped configuration of the heat exchanger 10. In this exemplary embodiment therefore the longitudinal directions 2 of the first flat tube 1′ and the second flat tube 1″ run at an inclination, in particular, transversely to one another. Here the outlet collector 23 has a different shape to the outlet collector 23 in FIGS. 4 and 5.
