Double-tube heat exchanger

Abstract

The present invention relates to a heat exchanger (100) for transferring thermal energy between two streams of fluid. The heat exchanger (100) comprises an inner tube segment (101), through which a first stream of fluid (103) can flow, and an outer tube segment (102), which surrounds the inner tube segment (101) in such a way that a flow channel (105) can be provided between the inner tube segment (101) and the outer tube segment (102) for a second stream of fluid (104) to flow through. The inner tube segment (101) has a flow element portion (106), from the outer face of which flow elements (107) for influencing the flow in the flow channel (105) protrude into the flow channel (105) without making contact with an inner face of the outer tube segment (102). The outer tube segment (102) has an inflow opening (108) for the inflow of the second stream of fluid (104) into the flow channel (105), the inflow opening (108) being designed in such a way that the second stream of fluid (104) can flow into the flow channel (105) with a radial directional component, such that the second stream of fluid (104) can flow onto the outer surface (112) in an inlet region (113) of the inner tube segment (101). The outer surface (112) in the inlet region (113) of the inner tube segment (101) is at least partly free of the flow elements (107).

Description

[0001] Our reference: B 1587 WO

[0002] Double pipe heat exchanger

[0003] Technical field

[0004] The present invention relates to a heat exchanger, in particular a double-pipe heat exchanger, for transferring thermal energy between two fluid flows and to a method for operating the heat exchanger.

[0005] Background of the invention

[0006] In double-pipe heat exchangers, heat (thermal energy) is transferred from one fluid stream to another. Double-pipe heat exchangers have two coaxially arranged pipes. A fluid stream flows between an inner and an outer pipe, allowing thermal energy to be exchanged via the wall of the inner pipe with another fluid stream flowing inside the inner pipe. This allows thermal energy from one fluid stream at a higher temperature to be transferred to another at a lower temperature. However, a large design is required to efficiently design a double-pipe heat exchanger.

[0007] Description of the invention

[0008] It is an object of the present invention to provide an efficient heat exchanger in a compact design.

[0009] This task is accomplished with a heat exchanger for transferring thermal energy and a method for operating a

[0010] AD: IG :tp Our reference: B 1587 WO

[0011] Heat exchanger according to the subject matter of the independent claims solved.

[0012] According to a first aspect of the present invention, a heat exchanger for transferring thermal energy between two fluid flows is described. The heat exchanger has an inner pipe segment through which a first fluid flow can pass, and an outer pipe segment which surrounds the inner pipe segment in such a way that a flow channel is provided between the inner pipe segment and the outer pipe segment for the flow of a second fluid flow. The inner pipe segment has a flow element section from the outer surface of which flow elements project into the flow channel to influence the flow, without touching an inner surface of the outer pipe segment.The outer pipe segment has an inlet opening for the second fluid flow to enter the flow channel. The inlet opening is designed such that the second fluid flow can enter the flow channel with a radial directional component, allowing it to flow onto the outer surface in an inlet region of the inner pipe segment. The outer surface in the inlet region of the inner pipe segment is partially or completely free of flow elements.

[0013] The inner and outer pipe segments can be made of the same material or of different materials. Materials with a high thermal conductivity coefficient are particularly common, such as steel, copper, aluminum, brass, or copper-nickel alloys. Furthermore, both the inner and outer pipe segments share a central axis. The central axis of the inner and outer pipe segments is, in particular, identical, so that both pipe segments extend coaxially. Our reference: B 1587 WO

[0014] Pipe segments can run in a straight line or have various curves. For example, the inner and outer pipe segments can meander.

[0015] The inner pipe segment, for example, has fluid openings at its axial ends, allowing the first fluid flow to enter or exit the inner pipe segment. Furthermore, the inner pipe segment can also have openings on its outer surfaces to allow the first fluid flow with a radial component to enter or exit.

[0016] The outer pipe segment completely encloses the inner pipe segment. In particular, the outer pipe segment can enclose the inner pipe segment along its entire length. In an exemplary embodiment, the outer pipe segment encloses the inner pipe segment only in sections. For example, a corresponding outer pipe segment can be arranged at several sections of the inner pipe segment.

[0017] The inlet area refers to the axial section of the inner

[0018] Pipe segment that is covered by a section of the outer pipe segment's outer surface, in which the inlet opening is formed.

[0019] The first and second fluid streams can, for example, be in a gaseous, vaporous, or liquid state. For instance, a second fluid stream is a heat-transferring fluid and flows through the flow channel between the inner and outer pipe segments. The first fluid stream flows within the first pipe segment, so thermal energy is exchanged between the first and second fluid streams via the wall of the inner pipe segment. The first and second fluid streams can flow along the same channel. Our reference: B 1587 WO

[0020] Flow direction (parallel to the central axis) or opposite, i.e., flow in opposite axial directions.

[0021] The flow element forms a flow body that projects from the outer surface of the inner pipe segment into the flow channel. This allows the flow element to influence the flow of the second fluid stream within the flow channel. The flow element can differ structurally from the inner pipe segment and may be made of the same or a different material. For example, the flow element can be detachably attached to the outer surface of the inner pipe segment. Furthermore, the flow element can be materially bonded to the outer surface of the inner pipe segment, for example, by welding. Finally, the flow element can be integrally formed as a single piece with the inner pipe segment.

[0022] In particular, a multitude of flow elements are arranged on the outer surface of the inner pipe segment. These flow elements can be arranged in a column-like configuration and project into the flow channel. Furthermore, the flow elements can extend in an axial and / or circumferential direction. For example, the flow elements can extend in a ring-like pattern along the circumference. Additionally, the flow elements can form fin-like elements extending in the axial direction. Furthermore, the flow elements can have helical windings and extend across the outer surface of the inner pipe segment with an axial and a circumferential direction. The flow elements can be spaced apart and run parallel to each other within the flow element section. The flow elements increase the contact area with the secondary fluid flow, thus making thermal exchange more efficient.Our reference: B 1587 WO.

[0023] According to one aspect of the present invention, the flow elements are not arranged over the entire outer surface of the inner pipe segment, but only in a flow element section that does not extend over the entire outer surface in the axial direction. In the region of the inlet opening, where the second fluid flow enters the flow channel through the inlet opening of the outer pipe segment, the outer surface of the inner pipe segment is free of flow elements and accordingly has a homogeneous and smooth outer surface. The flow channel thus forms circumferentially around the smooth outer surface of the inner pipe segment. If the second fluid flow now enters through the inlet region with a radial directional component, the flow elements initially do not influence the second fluid flow in the inlet region.In the inlet area, the second fluid flow can thus distribute itself homogeneously around the entire circumference of the inner pipe segment before flowing axially into the flow element section. The flow element section therefore connects axially downstream of the inlet area.

[0024] This offers the technical advantage that a complete circumferential distribution of the second fluid flow around the outer surface of the inner tube segment is initially provided, without the flow elements obstructing this distribution within the adjustment range. This further results in the second fluid flow only entering the flow element section and the flow elements within it once a predominantly homogeneous circumferential distribution has been achieved. Thus, all flow elements are circumferentially permeated by the second fluid flow, increasing the efficiency of the heat exchanger and allowing for a smaller design with the same heat exchanger performance. Our reference: B 1587 WO

[0025] According to another exemplary embodiment, the inner surface of the outer pipe segment maintains a constant distance from a central axis of the outer pipe segment in the inlet region and in the flow element section. In other words, the inner diameter of the outer pipe segment can remain constant in the inlet region and in the flow element section. Thus, flow losses in the axial direction can be avoided.

[0026] For example, the flow channel between the inner surface of the outer pipe segment and the outer surface of the inner pipe segment can vary in the axial direction to create specific flow channel characteristics. According to the exemplary embodiment, the outer diameter of the inner pipe segment can vary, while the inner diameter of the outer pipe segment remains constant. Furthermore, the radially projecting flow elements can vary in the axial direction.

[0027] According to another exemplary embodiment, the flow element section adjoins the inlet region of the inner pipe segment at one end, and a termination section adjoins it at an axially opposite end. At this termination section, an end segment of the outer pipe segment is sealedly coupled to the outer surface of the inner pipe segment to axially delimit the flow channel. The outer pipe segment can, for example, form an end face whose normal is parallel to the axial direction, with the end face forming a sealing collar around the outer surface of the inner pipe segment. This sealing collar can, for example, be attached to the outer surface of the inner pipe segment by means of a weld.

[0028] According to another exemplary embodiment, the flow elements extend in the axial direction within the Our reference: B 1587 WO

[0029] The flow elements extend into a section of the flow. These flow elements can extend in an axial direction and / or along the circumferential direction. For example, the flow elements can extend in a ring-like shape along the circumferential direction. Furthermore, the flow elements can form fin-like elements extending in the axial direction.

[0030] According to another exemplary embodiment, the flow elements extend axially in a helical fashion within the flow element section. The flow elements form, for example, screw-like turns and extend with an axial directional component and a circumferential directional component over the outer surface of the inner pipe segment. The flow elements can be spaced apart and run parallel to each other within the flow element section.

[0031] According to another exemplary embodiment, the flow elements have an angle of 30° to 60°, in particular 45°, along their outer surface relative to the axial direction. This angle is determined, in particular, on a projection surface of the flow elements and the axial direction. Thus, the fluid flowing axially from the inlet opening to the outlet opening is deflected at an angle between 30° and 60°, so that the second fluid flow 104 flows both axially and along the surface of the inner pipe segment. This creates a long contact area between the second fluid flow and the outer surface of the inner pipe segment.

[0032] According to another exemplary embodiment, the flow channel between the outer surface of the inner pipe segment and the inner surface of the outer pipe segment has a flow width in the radial direction, wherein the flow elements are designed, Our reference: B 1587 WO, such that the flow elements have a height in the radial direction between 50% and 95%, in particular between 60% and 75%, of the flow width. It has been found that this dimensioning results in an optimal ratio between flow resistance and heat output. The gap between the inner surface of the outer pipe segment and the flow elements allows the pressure in the flow channel to be reduced.For example, if the flow elements were to come into contact with the inner surface of the outer pipe segment and thus close the gap, very high pressures would occur, which could cause damage in the outer pipe segment.

[0033] Furthermore, this design offers an advantage in heat transfer. For example, if the inner pipe segment is hot, the thermal energy is transferred through its wall to the flow elements. The undisturbed gap between the flow elements and the inner surface of the outer pipe segment allows sufficient unimpeded flow for the second fluid stream, while a portion of this stream flows between the flow elements, exchanging thermal energy. If the flow elements were to touch the outer, for example, colder pipe segment, the tips of the flow elements would cool down more than, for example, the base of the flow elements on the inner pipe segment. This can lead to thermal stresses, thus increasing the risk of damage.

[0034] According to another exemplary embodiment, the flow elements have a cross-sectional shape with a base at the outer surface of the inner pipe segment and a free end in the flow channel. The cross-sectional width of the flow elements at the base is greater than the cross-sectional width at the free end. From the outer surface of the inner pipe segment, the flow elements taper towards their free end, so to speak (Our reference: B 1587 WO), resulting in a cross-sectional shape that is, for example, pyramidal. Furthermore, as mentioned in the following example, the apex can be plateau-shaped.

[0035] According to another exemplary embodiment, the flow elements each have a free end section with a flow surface in the flow channel, wherein the flow surface in the flow channel has the narrowest cross-section between the free end section and the inner surface of the outer pipe segment, and wherein the flow surface extends with a directional component in the axial direction.

[0036] According to another exemplary embodiment, the flow surface runs parallel to the inner surface of the outer pipe segment. This means that the flow surface of the free end section and the inner surface of the outer pipe segment have no deviations or inclinations relative to each other and maintain a uniform distance over their entire length or area. The second fluid flow can thus flow without loss between the flow surface of the free end section and the inner surface of the outer pipe segment, and a pressure increase inside the pipe can be reduced.

[0037] According to another exemplary embodiment, the flow surface is curved. This can have a homogenizing effect on the flow characteristics.

[0038] According to another exemplary embodiment, the flow surface is tapered to a point. This can result in the desired formation of vortices.

[0039] According to another exemplary embodiment, the

[0040] Flow surface in axial direction: two elevation sections with a deeper one. Our reference: B 1587 WO

[0041] The connecting area that links the raised sections is affected. This can have a positive influence on flow efficiency and, for example, result in the desired vortex formation.

[0042] According to another exemplary embodiment, at least one of the two raised sections is tapered to a point. This can have a positive influence on flow efficiency and, for example, result in the desired formation of vortices.

[0043] According to another exemplary embodiment, at least one of the two raised sections is curved. This can have a positive influence on flow efficiency and, for example, result in the desired vortex formation.

[0044] According to another exemplary embodiment, the deeper connection area is concavely or convexly curved. This can have a positive influence on flow efficiency and, for example, result in the desired vortex formation.

[0045] According to another exemplary embodiment, two wall sections opposite the end section are formed between the end section and the outer surface of the inner pipe segment.

[0046] According to a further exemplary embodiment, at least one of the wall sections has a homogeneous flat surface, wherein the flat surface forms a surface angle of 60° to 89°, in particular 90°, with respect to the outer surface of the inner pipe segment. This can have a positive influence on the flow efficiency and, for example, result in the desired vortex formation. Our reference: B 1587 WO

[0047] According to another exemplary embodiment, at least one of the wall sections is concavely or convexly curved. This can have a positive influence on flow efficiency and, for example, result in a desired adjustment of the flow characteristics.

[0048] According to a further exemplary embodiment, the outer pipe segment has an outlet opening for the second fluid flow to flow out of the flow channel. The outlet opening is designed such that the second fluid flow can flow out of the flow channel with a radial component in an outlet region of the inner pipe segment. In particular, the outlet opening is arranged in a lateral surface of the outer pipe segment. The outlet region denotes the axial section of the inner pipe segment that is covered by a section of the lateral surface of the outer pipe segment in which the outlet opening is formed.

[0049] According to another exemplary embodiment, the outer surface in the outlet region of the inner pipe segment is partially or completely free of flow elements. In the region of the outlet opening, where the second fluid flow exits the outer pipe segment through the outlet openings, the outer surface of the inner pipe segment is free of flow elements and thus has a homogeneous and smooth outer surface. The flow channel is therefore formed circumferentially around the smooth outer surface of the inner pipe segment. If the second fluid flow now exits the outlet region with a radial directional component, the flow elements in the outlet region initially do not influence the second fluid flow. In the outlet region, the second fluid flow can exit without the flow elements amplifying disruptive turbulence in the outlet openings.The outlet area thus connects axially behind the flow element section. Our reference: B 1587 WO.

[0050] According to a further exemplary embodiment, the flow element section connects to the outlet region of the inner pipe segment at one end, and a further termination section connects to the axially opposite end. At this termination section, another end section of the outer pipe segment is sealedly coupled to the outer surface of the inner pipe segment to axially delimit the flow channel. The outer pipe segment can, for example, form an end face whose normal is parallel to the axial direction, with the end face forming a sealing collar around the outer surface of the inner pipe segment. This sealing collar can, for example, be attached to the outer surface of the inner pipe segment by means of a weld.

[0051] It should be noted that the embodiments described here represent only a limited selection of possible embodiments of the invention. It is possible to combine the features of individual embodiments in a suitable manner, so that a multitude of different embodiments are considered to be obviously disclosed to the person skilled in the art with regard to the embodiments explicitly described here. In particular, some embodiments of the invention are described by apparatus claims and other embodiments by method claims. However, it will be immediately clear to the person skilled in the art upon reading this application that, unless explicitly stated otherwise, in addition to a combination of features belonging to one type of subject matter, any combination of features belonging to different types of subject matter is also possible. Our reference: B 1587 WO

[0052] Brief description of the drawings

[0053] For further explanation and better understanding of the present invention, exemplary embodiments are described in more detail below with reference to the accompanying drawings. These show:

[0054] Fig. 1 shows a schematic representation of a partial area of ​​a heat exchanger according to an exemplary embodiment of the present invention.

[0055] Fig. 2 shows an enlarged view of cross-sections of flow elements according to an exemplary embodiment of the present invention.

[0056] Fig. 3 shows a heat exchanger with an inner tube segment and several outer tube segments according to an exemplary design.

[0057] embodiment of the invention.

[0058] Figs. 4 to 16 show exemplary embodiments of different cross-sectional shapes of the flow element according to exemplary embodiments of the invention.

[0059] Detailed description of exemplary implementation forms

[0060] Identical or similar components in different figures are identified by the same reference numbers. The representations in the figures are schematic.

[0061] Fig. 1 shows a schematic representation of a section of a heat exchanger 100 for transferring thermal energy between two fluid flows. The heat exchanger 100 has an inner pipe segment 101, Our reference: B 1587 WO, through which a first fluid flow 103 can pass, and an outer pipe segment 102, which encloses the inner pipe segment 101 in such a way that a flow channel 105 is provided between the inner pipe segment 101 and the outer pipe segment 102 for the flow of a second fluid flow 104. The inner pipe segment 101 has a flow element section 106, from the outer surface of which flow elements 107 project into the flow channel 105 to influence the flow, without touching an inner surface of the outer pipe segment 102.The outer pipe segment 102 has an inlet opening 108 for the second fluid flow 104 to flow into the flow channel 105, wherein the inlet opening 108 is designed such that the second fluid flow 104 can flow into the flow channel 105 with a radial directional component, such that the second fluid flow 104 can flow onto the outer surface 112 in an inlet region 113 of the inner pipe segment 101. The outer surface 112 in the inlet region 113 of the inner pipe segment 101 is free of the flow elements 107.

[0062] The inner pipe segment 101 and the outer pipe segment 102 have a central axis 110. The central axis 110 of the inner pipe segment 101 and the outer pipe segment 102 are, in particular, identical, so that both pipe segments 101, 102 are coaxial with each other. The inner pipe segment 101 and the outer pipe segment 102 can be straight or have different curves.

[0063] The inner pipe segment 101 has fluid openings at its axial ends, allowing the first fluid flow 103 to flow into or out of the inner pipe segment 101. Furthermore, the inner pipe segment 101 can also have openings on its outer surfaces to allow the first fluid flow 103 to flow in or out with a radial component 111. Our reference: B 1587 WO

[0064] The outer pipe segment 102 completely encloses the inner pipe segment 101. In the exemplary embodiment, the outer pipe segment 102 only partially encloses the inner pipe segment 101.

[0065] The inlet area refers to the axial section of the inner tube segment 101, which is covered by a section of the outer surface of the outer tube segment 101, in which the inlet opening is formed.

[0066] For example, a second fluid stream 104, a heat-transferring fluid, flows through the flow channel 105 between the inner pipe segment 101 and the outer pipe segment 102. The first fluid stream 103 flows within the first pipe segment 101, so that thermal energy is exchanged between the first fluid stream 103 and the second fluid stream 104 via the wall of the inner pipe segment 101. The first fluid stream 103 and the second fluid stream 104 can flow in opposite directions (parallel to the central axis 110).

[0067] The flow element 107 forms a flow body that projects from the outer surface of the inner pipe segment 101 into the flow channel 105. The flow element 107 thus influences the flow of the second fluid stream 104 within the flow channel. The flow element 107 can differ structurally from the inner pipe segment 101 and may be made of the same or a different material. For example, the flow element 107 can be integrally formed as a single piece with the inner pipe segment 101.

[0068] In particular, a large number of flow elements 107 are arranged on the outer surface 112 of the inner pipe segment 101. The flow elements 107 extend in helical coils and, with an axial directional component 110 and a circumferential directional component, over the outer surface 112 of the inner pipe segment 101. The flow elements 107 can be spaced apart and run parallel to each other in the flow element section 106. In the embodiment shown, the flow elements 107 have an angle of approximately 45° along the outer surface 112 relative to the axial direction 110.Thus, the second fluid flow 104, which flows in axial direction 110 from the inlet opening 108 to the outlet opening 109, is deflected at an angle of 45°, so that the second fluid flow 104 flows on the one hand in axial direction 110 and on the other hand in circumferential direction around the outer surface 112 of the inner pipe segment 101.

[0069] According to the invention, the flow elements 107 are not arranged over the entire outer surface 112 of the inner pipe segment 101, but only in the flow element section 106 that does not extend over the entire outer surface of the first pipe segment 101 in the axial direction 112. In the region of the inlet opening 108, where the second fluid flow 104 enters the flow channel 105 through the inlet opening 108 of the outer pipe segment 102, the outer surface 112 of the inner pipe segment 101 is formed without flow elements 107 and accordingly has a homogeneous and smooth outer surface 112.

[0070] From the inlet opening 108 in the axial direction 110 to the beginning of the flow element section 106, where the flow elements 107 begin to form, a transition section 117 is provided in which no flow elements 107 are formed. In the transition section 117, the distance between the outer surface 112 of the inner pipe segment 101 and the inner surface 201 of the outer pipe segment 102 is constant. Only after a certain distance in the axial direction 110 do the flow elements 107 begin to form. Thus, the second fluid flow 104 has more time and space to fill the entire circumference around the inner pipe segment 101 and subsequently utilize the flow elements 107 around the entire circumference of the inner pipe segment 101.

[0071] The flow channel 105 thus forms circumferentially around the smooth outer surface 112 of the inner pipe segment 101. If the second fluid flow 104 now flows in through the inlet opening 108 with a radial directional component 111, the flow elements 107 in the inlet region 113 initially do not influence the second fluid flow 104. In the inlet region 113, the second fluid flow 104 can thus distribute itself homogeneously in the circumferential direction completely around the inner pipe segment 101 before the second fluid flow 104 flows in the axial direction 110 into the flow element section 106. The flow element section 106 thus connects in the axial direction 110 downstream of the inlet region 113.

[0072] For example, in the axial direction 116, the flow channel 105 between the inner surface 201 of the outer pipe segment 102 and the outer surface 112 of the inner pipe segment 101 can vary in order to produce specific flow channel properties. The outer diameter of the inner pipe segment 101 can vary, while the inner diameter of the outer pipe segment 102 remains constant.

[0073] The inlet region 113 of the inner pipe segment 101 is joined at one end by the flow element section 106 and at an axially opposite end by a closing section 114, to which an end section of the outer pipe segment 102 is sealedly coupled with the outer surface 112 of the inner pipe segment 101 in order to axially delimit the flow channel 105. The outer pipe segment 102 can, for example, form an end face whose normal is parallel to the axial direction 110, Our reference: B 1587 WO, wherein the end face forms a sealing collar around the outer surface 112 of the inner pipe segment 101.

[0074] The flow elements 107 extend in an axial direction 110 in a helical fashion within the flow element section 106. The flow elements 107 form, for example, helical windings and extend with an axial directional component and a circumferential directional component over the outer surface 112 of the inner pipe segment 101. The flow elements 107 run spaced apart and parallel to each other within the flow element section 106.

[0075] The inner surface 201 of the outer pipe segment 102 has a constant distance to the central axis of the outer pipe segment 102 in the inlet region 113 and in the region of the flow element section 106. In other words, the inner diameter of the outer pipe segment 102 can remain constant in the inlet region 113 and in the region of the flow element section 106.

[0076] The outer pipe segment 102 has an outlet opening 109 for the outflow of the second fluid flow 104 from the flow channel 105. The outlet opening 109 is designed such that the second fluid flow 104, with a radial directional component 111, can flow out of the flow channel 105 in an outlet region 115 of the inner pipe segment 101. In particular, the outlet opening 109 is arranged in a lateral surface of the outer pipe segment 102. The outlet region 115 denotes the axial section of the inner pipe segment 101 that is covered by a section of the lateral surface of the outer pipe segment 102 in which the outlet opening 109 is formed.

[0077] The outer surface 112 in the outlet area 115 of the inner pipe segment 101 is also free of the flow elements 107. Our reference: B 1587 WO

[0078] In the area of ​​the outlet opening 109, where the second fluid flow 104 exits the outer pipe segment 102 through the outlet openings 109, the outer surface 112 of the inner pipe segment 101 is free of flow elements 107 and therefore has a homogeneous and smooth outer surface. The flow channel 105 thus forms around the entire smooth outer surface 112 of the inner pipe segment 101. If the second fluid flow 104 now exits through the outlet area 115 with a radial directional component 111, the flow elements 107 in the outlet area 115 initially do not influence the second fluid flow 104. In the outlet area 115, the second fluid flow 104 can exit without the flow elements 107 intensifying disruptive turbulence in the outlet openings 109. The outlet area 115 thus connects in axial direction 110 behind the flow element section 106.

[0079] The outlet region 115 of the inner pipe segment 101 is connected at one end to the flow element section 106, and at an axially opposite end to a further end section 114, to which another end section of the outer pipe segment 102 is coupled sealingly with the outer surface 112 of the inner pipe segment 101 in order to axially delimit the flow channel 105. The outer pipe segment 102 can, for example, form an end face whose normal is parallel to the axial direction 110, with the end face forming a sealing collar around the outer surface 112 of the inner pipe segment 101.

[0080] Fig. 2 shows an enlarged view of cross-sections of flow elements 107. The flow channel 105 has a flow width Sb in the radial direction 111 between the outer surface 112 of the inner pipe segment 101 and the inner surface 201 of the outer pipe segment 102, wherein the flow elements 107 are designed such that they have a height h in the radial direction 111 between 50% and 95% of the flow width Sb. The gap (flow channel 105) between the inner surface 201 of the outer pipe segment 102 and the flow elements 105 allows the pressure in the flow channel 105 to be reduced. The gap between the flow elements 107 and the inner surface 201 of the outer pipe segment 102, which is not interrupted by flow elements 107, allows the second fluid flow 104 to flow along without disturbance, while part of the second fluid flow 104 flows between the flow elements 107.

[0081] The flow elements 107 have a cross-sectional shape with a base 202 at the outer surface 112 of the inner tube segment 101 and a free end 203 in the flow channel 105. The cross-sectional width of the flow elements 107 at the base 202 is greater than the cross-sectional width at the free end 203. The flow elements 107 taper from the outer surface 112 of the inner tube segment 101 towards their free end 203.

[0082] The flow elements 107 have a free end section 203 in the flow channel 105, wherein the free end section 203 has a flow surface 204 which extends in the axial direction 110 and the flow surface 204 runs, in particular, parallel to the inner surface 201 of the outer pipe segment 102. This means that the flow surface 204 of the free end section 203 and the inner surface 201 of the outer pipe segment 102 have no deviations or inclinations relative to each other and maintain a uniform distance over their entire length or area. The second fluid flow 104 can thus flow between the flow surface 204 of the free end 203 and the inner surface 201 of the outer pipe segment 102. Our reference: B 1587 WO

[0083] Fig. 3 shows a heat exchanger 100 with an inner tube segment 101 and several outer tube segments 102 according to an exemplary embodiment of the invention. For example, a corresponding outer tube segment 102 can be arranged at several sections of the inner tube segment 101. The inner tube segment 101 has a meandering shape. The outer tube segments 102 are arranged section by section at straight sections of the inner tube segment 102.

[0084] An outer pipe segment 102 encloses an area of ​​the inner pipe segment.

[0085] 101 complete. Each of the outer tube segments 102 has corresponding inlet openings 108 and outlet openings 109, so that a second fluid flow 104 can flow into the corresponding flow channel 105. With the illustrated embodiment of a heat exchanger 100, a high power output can be achieved in a compact design.

[0086] Figures 4 to 15 show exemplary embodiments of different cross-sectional shapes of the flow element 103. The flow elements 107 each have a free end section 203 with a flow surface 204 in the flow channel 105, wherein the flow surface 204 in the flow channel 105 is the narrowest cross-section between the free end section 203 and the inner surface 201 of the outer tube segment.

[0087] 102 exhibits- The flow surface 204 runs along the flow element 107 and in the cross-section of the flow element 107 the flow surface 204 extends with a directional component in the axial direction 110. Between the end section 203 and the outer surface 112 of the inner pipe segment 101, two wall sections 123 opposite the end section 203 are formed.

[0088] In Fig. 4, for example, wall sections 123 are concavely curved. Our reference: B 1587 WO

[0089] In Fig. 5, for example, the wall sections 123 are formed as flat and straight, with the wall sections 123 having a surface angle to the outer surface 112 of 75° to 80°.

[0090] In Figure 4 and Figure 5, the flow surfaces 204 run parallel to the inner surface 201 of the outer pipe segment 102.

[0091] In Fig. 6, the flow surface 204 between the wall sections 123 is curved. The wall sections 123 are concave.

[0092] In Fig. 7, the flow surface 204 is tapered between the wall sections 123. The wall sections 123 are concavely curved.

[0093] In Fig. 8, for example, the wall sections 123 are flat and straight, with the wall sections 123 having a surface angle to the outer surface 112 of 75° to 80°. The flow surface 204 between the wall sections 123 can be flat or slightly curved.

[0094] In Fig. 9, the wall sections 123 have a homogeneous, flat surface, with the wall sections 123 being orthogonal to the outer surface 112. The flow surface 204 between the wall sections 123 is curved.

[0095] In Fig. 10, the wall sections 123 have a homogeneous, flat surface, with the wall sections 123 having a surface angle to the outer surface 112 of 75° to 80°. The flow surface 204 is tapered between the wall sections 123. Our reference: B 1587 WO

[0096] In Fig. 11, for example, the wall sections 123 are convexly curved. The flow surface 204 between the wall sections 123 is curved.

[0097] Figures 12 to 15 show the flow surface 204 of the flow elements 107 in the axial direction 110 having two raised sections 121 with a deeper connecting area 122 that connects the raised sections 121.

[0098] In Fig. 12, the deeper connecting areas 122 are arched or concavely curved. The raised sections 121 taper to a point between the wall sections 123. The wall sections 123 are concavely curved.

[0099] In Fig. 13, the deeper connection areas 122 are arched or concavely curved. The flow surface 204 at the raised sections 121 is convexly curved. The wall sections 123 are orthogonal to the outer surface 112.

[0100] In Fig. 14, the deeper connection areas 122 are arched or concavely curved. The flow surface 204 at the raised sections 121 is tapered to a point. The wall sections 123 are orthogonal to the outer surface 112.

[0101] In Fig. 15, the deeper connection areas 122 are arched or concavely curved. The flow surface 204 at the raised sections 121 is convexly curved. The wall sections 123 are concavely curved.

[0102] In Fig. 16, for example, the wall sections 123 are formed as flat and straight surfaces, with the wall sections 123 forming a surface angle to the Our reference: B 1587 WO

[0103] The outer surface 112 has an angle of 100° to 115°. The flow surface 204 between the wall sections 123 can be straight or slightly curved. It should also be noted that "comprehensive" does not exclude any other elements or steps, and "a" or "an" does not exclude a plurality.

[0104] Furthermore, it should be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps from other embodiments described above. Reference numerals in the claims are not to be considered as limitations.

[0105]

[0106] 100 heat exchangers

[0107] 101 inner pipe segment

[0108] 102 outer pipe segment

[0109] 103 first fluid flow

[0110] 104 second fluid flow

[0111] 105 Flow channel

[0112] 106 Flow element section

[0113] 107 Flow element

[0114] 108 Inlet opening

[0115] 109 Outlet opening

[0116] 110 Axial direction

[0117] 111 Radial direction

[0118] 112 Exterior surface

[0119] 113 Entrance area

[0120] 114 Final Section

[0121] 115 Outlet area

[0122] 116 further concluding section

[0123] 117 Transition area

[0124] 201 Inner surface of the outer tube segment

[0125] 202 foot area

[0126] 203 free end, final section

[0127] 204 Flow area

[0128] 121 Survey Section

[0129] 122 Connection area

[0130] 123 Wall section a Angle

[0131] Sb flow width h height flow element

Claims

Our reference: B 1587 WO Patent claims 1. Heat exchanger (100) for transferring thermal energy between two fluid flows, the heat exchanger (100) having an inner tube segment (101) which is supplied by a first fluid flow (103) is permeable, an outer pipe segment (102) which encloses the inner pipe segment (101) in such a way that a flow channel (105) between the inner pipe segment (101) and the outer pipe segment (102) is provided for the flow of a second fluid stream (104), wherein the inner pipe segment (101) has a flow element section (106) from the outer surface of which flow elements (107) project into the flow channel (105) to influence the flow without touching an inner surface of the outer pipe segment (102), wherein the outer pipe segment (102) has an inlet opening (108) for the second fluid stream (104) to flow into the flow channel (105), wherein the inlet opening (108) is designed such that the second fluid stream (104) enters the flow channel (105) with a radial directional component. It is possible for the second fluid flow to flow in. (104) is flowable onto the outer surface (112) in an inlet area (113) of the inner tube segment (101), wherein the outer surface (112) in the inlet area (113) of the inner tube segment (101) is partially free of the flow elements (107).

2. Heat exchanger (100) according to claim 1, wherein the inner surface (201) of the outer tube segment in the inlet area and in the area of ​​the flow element section (106) forms a constant distance to a central axis of the outer tube segment (102). Our reference: B 1587 WO 3. Heat exchanger (100) according to claim 1 or 2, wherein the flow element section (106) is connected to the inlet region (113) of the inner tube segment (101) at one end and a termination section (114) is connected to an axially opposite end, in which an end section of the outer tube segment (102) is coupled sealingly to the outer surface of the inner tube segment (101) in order to axially limit the flow channel (105).

4. Heat exchanger (100) according to one of claims 1 to 3, wherein the flow elements (107) extend in the axial direction (110) within the flow element section (106).

5. Heat exchanger (100) according to claim 4, wherein the flow elements (107) extend in an axial direction (110) in a threaded manner within the flow element section (106).

6. Heat exchanger (100) according to claim 5, wherein the flow elements (107) along the outer surface (112) have an angle of 30° to 60°, in particular 45°, relative to the axial direction (110).

7. Heat exchanger (100) according to any one of claims 1 to 6, wherein the flow channel (105) between the outer surface (112) of the inner tube segment (101) and the inner surface (201) of the outer tube segment (102) has a flow width (Sb) in the radial direction (111), wherein the flow elements (107) are designed such that the flow elements (107) have a height (h) in the radial direction (111) between 50% and 95%, in particular between 60% and 75% of the flow width (Sb). Our reference: B 1587 WO 8. Heat exchanger (100) according to any one of claims 1 to 7, wherein the flow elements (107) have a cross-sectional shape with a foot region (202) on the outer surface (112) of the inner tube segment (101) and with a free end (203) in the flow channel (105), wherein a cross-sectional width of the flow elements (107) in the foot region (202) is greater than a cross-sectional width at the free end (203) of the flow elements (107).

9. Heat exchanger (100) according to any one of claims 1 to 8, wherein the flow elements (107) each have a free end section (203) with a flow surface (204) in the flow channel (105), wherein the flow surface (204) in the flow channel (105) has the narrowest cross-section between the free end section (203) and the inner surface (201) of the outer tube segment (102), wherein the flow surface (204) extends with a directional component in the axial direction (110).

10. Heat exchanger (100) according to claim 9, wherein the flow surface (204) runs parallel to the inner surface (201) of the outer tube segment (102).

11. Heat exchanger (100) according to claim 9, wherein the flow surface (204) is curved.

12. Heat exchanger (100) according to claim 9, wherein the flow surface (204) is tapered.

13. Heat exchanger (100) according to claim 9, wherein the flow surface (204) has two raised sections (121) in the axial direction (110) with a deeper connecting area (122) that connects the raised sections (121). Our reference: B 1587 WO 14. Heat exchanger (100) according to claim 13, wherein at least one of the two raised sections (121) is tapered.

15. Heat exchanger (100) according to claim 13 or 14, wherein at least one of the two raised sections (121) is curved.

16. Heat exchanger (100) according to one of claims 13 to 15, wherein the lower connection area (122) is concavely or convexly curved.

17. Heat exchanger (100) according to one of claims 9 to 16, wherein two wall sections (123) opposite the end section (203) are formed between the end section (203) and the outer surface (112) of the inner tube segment (101).

18. Heat exchanger (100) according to claim 17, wherein at least one of the wall sections (123) has a homogeneous straight surface, the surface forming a surface angle to the outer surface (112) of the inner tube segment (101) of 60° to 89°, in particular 90°.

19. Heat exchanger (100) according to claim 17 or 18, wherein at least one of the wall sections (123) is concavely or convexly curved.

20. Heat exchanger (100) according to any one of claims 1 to 19, Our reference: B 1587 WO wherein the outer pipe segment (102) has an outlet opening (109) for the outflow of the second fluid flow (104) from the flow channel (105), wherein the outlet opening (109) is designed such that the second fluid flow (104) can be discharged from the flow channel (105) with a radial directional component in an outlet area (115) of the inner pipe segment (101).

21. Heat exchanger (100) according to claim 20, wherein the outer surface (112) in the outlet area (115) of the inner tube segment (101) is free of the flow elements (107). 22 Heat exchanger (100) according to claim 20, or 21, wherein the flow element section connects to the outlet region (115) of the inner tube segment (101) at one end and a further termination section (116) connects to an axially opposite end, in which a further end section of the outer tube segment (102) is coupled sealingly to the outer surface of the inner tube segment (101) in order to axially limit the flow channel (105).

23. Method for transferring thermal energy between two fluid flows using a heat exchanger (100) according to any one of claims 1 to 22.

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