PLASTIC MATERIAL INTERNAL HEAT EXCHANGER

Abstract

The invention relates to a device (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i) for heat exchange, in particular in a refrigerant circuit. The device (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i) comprises at least one first flow path (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i) and at least one second flow path (3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i) which, in a cross section perpendicular to a longitudinal direction (L) of the device (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i), are disposed coaxially with respect to one another with each comprising at least one flow channel (4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i). One wall of the at least one flow channel (4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i) of at least one flow path (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i) is realized of a synthetic material. The flow paths (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i) are each implemented as a multiplicity of flow channels (4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i).

Claims

1-14. (canceled)

1. A device for heat exchange, in particular in a refrigerant circuit, comprising at least one first flow path and at least one second flow path which, in a cross section perpendicular to a longitudinal direction (L) of the device, are disposed coaxially with respect to one another, wherein the flow paths comprise in each instance at least one flow channel and one wall of the at least one flow channel of at least one flow path is realized from a synthetic material, wherein the flow paths are each implemented as a multiplicity of flow channels.

2. A device according to claim 1, wherein at least one flow path is implemented as a multiplicity of flow channels each with circular flow cross section.

3. A device according to claim 2, wherein one wall of the at least one flow channel of at least one second flow path is realized from a metal.

4. A device according to claim 1, wherein each flow channel is developed with a separate wall, wherein the walls of adjacently disposed flow channels are in contact on one another.

5. A device according to claim 1, wherein each flow channel is developed such that it is delimited by a wall, wherein adjacently disposed flow channels are in each instance separated from each other by a common wall.

6. A device according to claim 1, wherein a first flow path is disposed in the proximity of an axis of symmetry of the device as well as has a circular form in cross section, and that flow channels of a second flow path are disposed coaxially about the first flow path which, in their entirety, have a circular ring form.

7. A device according to claim 6, wherein, starting at the axis of symmetry toward the outside, flow channels of a first flow path are disposed coaxially about flow channels of a second flow path which, in their entirety, have a circular ring form, such that at least one second flow path is disposed such that it is delimited by two first flow paths and that flow channels of a further second flow path are disposed coaxially about flow channels of a first flow path which, in their entirety, have a circular ring form.

8. A device according to claim 6, wherein the flow channels are disposed in a single row or in multiple rows.

9. A device according to claim 1, wherein the flow channels are aligned parallel to one another in the longitudinal direction (L).

10. A device according to claim 1, wherein at least one flow path is developed such that it is circular ring-shaped in a cross section perpendicular to the longitudinal direction (L), wherein the flow path is distribute into partial circular ring-shaped flow channels by webs oriented in the direction of a radius.

11. A device according to claim 10, wherein flow channels are developed in the webs.

12. A device according to claim 1, wherein at the front faces one connection element in each case for the first flow path and one connection element for the second flow path or a combination connection element is disposed in which are disposed connection flow channels continuing the flow channels of the first flow paths in the longitudinal direction (L), and at least one ring channel is implemented as a connection flow channel of the second flow paths, which connects the volumes of the second flow channels with one another.

13. A device according to claim 12, wherein the ring channel comprises an outlet opening into which opens out a connection line.

14. A refrigerant circuit comprising an internal heat exchanger, wherein the internal heat exchanger comprises the device of claim 1.

15. A refrigeration circuit according to claim 14, wherein the refrigeration circuit is an air conditioning system for conditioning the air of a passenger compartment of a motor vehicle.

Description

[0036] Further details, features and advantages of embodiments of the invention are evident in the following description of embodiment examples with reference to the associated drawing. Therein depicts in each Figure a device for heat exchange with first and second flow paths disposed coaxially with respect to one another:

[0037] FIG. 1a-1e: in cross section and in perspective view, respectively, flow paths developed with circular flow channels, wherein the flow channels of the first flow path form a circular flow path and the flow channels of the second flow path are disposed as a circular ring about the first flow path,

[0038] FIG. 2: in cross section and perspective view flow paths implemented with circular flow channels which are disposed, from the inside toward the outside, adjacently as circular rings,

[0039] FIG. 3a, 3b: in cross section with flow paths, implemented with circular flow channels, disposed, from the inside to the outside, adjacently and alternatingly as circular rings,

[0040] FIG. 3c: from FIG. 3a in cross section with flow paths implemented of circular flow channels adapted to interspaces,

[0041] FIG. 4: in cross section flow paths, implemented with one circular flow channel and rectangular flow channels, which are disposed, from the inside to the outside, adjacently as circular rings,

[0042] FIG. 5: in perspective view in cross section with flow paths, implemented with one circular flow channel and elongated as well as curved flow channels, which are disposed, from the inside to the outside, adjacently as circular rings,

[0043] FIG. 6a-6e: in a configuration with a connection element each for the first and the second flow path or with a combination connection element.

[0044] In FIG. 1a to 1e a device 1a for heat exchange with first and second flow paths 2a, 3a, disposed coaxially with respect to one another, is shown in cross section and in perspective view along the direction of flow, respectively, which direction of flow corresponds to the longitudinal direction L. The device 1a is substantially developed in circular cylindrical form and extends in a longitudinal direction L.

[0045] The flow paths 2a, 3a are each implemented with flow channels 4a, 5a that are circular in cross section. The flow channels 4a of the first flow path 2a form a circular flow path and the flow channels 5a of the second flow path 3a are disposed in the form of a circular ring about the first flow path 2a. The flow channels 4a of the first flow path 2a are identical as are the flow channels 5a of the second flow path 3a, wherein the flow channels 4a of the first flow path 2a can differ from the flow channels 5a of the second flow path 3a. The differences refer in particular to the free flow cross sections as well as the wall thicknesses and therewith to the inner and outer radii or the diameters.

[0046] As the throughflow areas, the free cross sections of the flow paths 2a, 3a can correspond approximately to the throughflow areas of the coaxial tubes of aluminum known within prior art.

[0047] The flow channels 4a, 5a extend in a straight line and parallel along the longitudinal direction L. According to an embodiment, not shown, the flow channels 4a, 5a are disposed in the longitudinal direction L turned or twisted about a center axis of the device.

[0048] FIGS. 1a, 1d and 1e show clearly that the flow channels 4a, each spaced apart at the same distance from the center axis of the device la and therewith from the flow channel 4a, disposed in the center, of the first flow path 2a, according to a first embodiment are aligned circularly about the center axis. The number of flow channels 4a per circle increases with increasing distance from the center axis.

[0049] According to a second embodiment, not shown, the number of flow channels 4a per circle remains constant with increasing distance from the center, wherein the outer radii of the flow channels 4a increase with increasing distance from the center axis.

[0050] In the device 1a depicted in FIGS. 1b and 1c the flow channels 4a of the first flow path 2a according to a second embodiment are each aligned in rows with respect to one another in a direction perpendicular to the longitudinal direction L, The flow channels 4a of adjacently disposed rows are each aligned offset with respect to one another about the outer radius of the flow channel 4a. The number of flow channels 4a per row increases with increasing distance from the row disposed through the center axis.

[0051] As the flow channels 4a of the first flow path 2a, the flow channels 5a of the second flow path 3a can each be disposed in the first or the second embodiment, wherein the flow channels 5a of the second flow path 3a can also be disposed in the first embodiment and the flow channels 4a of the first flow path 2a in the second embodiment, or conversely. The different embodiments refer herein to the formation of the diameters of the flow channels depending on the distance from the center axis.

[0052] FIG. 2 depicts in perspective view along the direction of flow a device 1b in cross section for heat exchange with first and second flow paths 2b, 3b, disposed coaxially with respect to one another.

[0053] In contrast to the device 1a of FIGS. 1a, 1d and 1e, the flow channels 4b of the first flow paths 2b and the flow channels 5b of the second flow paths 3b form each circular ring-shaped flow paths 2b, 4b, which are disposed, from the inside to the outside, adjacently as circular rings. Only the circular flow channel 4b disposed in the center as the single component forms a first flow path 2b.

[0054] In the direction of the radius of the device 1b the first flow paths 2b are each implemented as circular rings with the width of one flow channel 4b, i.e. implemented of one flow channel 4a, while the second flow paths 3b are implemented with the width of two flow channels 5b, i.e. implemented of two flow channels 5b. Each first flow path 2b is therewith encompassed by two flow channels 5b of the second flow path 3b. The flow channels 5b of the second flow paths 3b, adjacently disposed in the direction of the radius of device 1b, are disposed in contact with one another.

[0055] The flow paths are disposed, starting at the center toward the outside, in the sequence first flow path 2b, second flow path 3b, first flow pat 2b, second flow path 3b, first flow path 2b as well as second flow path 3b.

[0056] The total throughflow area of the first flow paths 2b is in the range of 180 mm to 450 mm.sup.2, in particular in the range, for example, of 200 mm.sup.2 to 420 mm.sup.2, specifically in the range of 300 mm.sup.2 to 420 mm.sup.2, while the total throughflow area of the second flow paths 3b is in the range of 40 mm.sup.2 to 100 mm.sup.2, in particular approximately 50 mm.sup.2 or 70 mm.sup.2, specifically in the range of 45 mm.sup.2 to 63 mm.sup.2.

[0057] When operating the device lb as internal heat exchanger of a refrigerant circuit, the first flow paths 2b are passed through by refrigerant at low-pressure level and the second flow paths 3b by refrigerant at high-pressure level. Due to the material-specific properties of the refrigerant on the high-pressure side, the requisite total throughflow area is herein markedly lower on the high-pressure side than the requisite total throughflow area on the low-pressure side.

[0058] A flow channel 4b of the first flow path 2b has an inner diameter in the range of 0.8 mm to 1.5 mm, preferably of 1.2 mm, and a wall thickness in the range of 0.1 mm to 0.3 mm, preferably of 0.2 mm. A flow channel 5b of the second flow path 3b is also developed with an inner diameter in the range of 0.8 mm to 1.5 mm, preferably of 1.2 mm, as well as a wall thickness in the range of 0.2 mm to 0.6 mm, preferably of, for example, 0.4 mm, specifically of 0.37 mm.

[0059] The device 1b has an outer diameter in the range of 20 mm to 30 mm, preferably in the range of 22 mm to 27 mm, specifically in the range of 24 mm to 26 mm, and is scalable in size, in particular in total diameter. The configuration, or the number of flow paths 2b, 3b, and that of the flow channels 4b, 5b forming the flow paths 2b 3b, can herein be varied.

[0060] In FIG. 3a is depicted in cross section in perspective view along the direction of flow, a device 1 c for heat exchange with first and second flow paths 2c, 3c disposed coaxially with respect to one another. In contrast to the device lb of FIG. 2, the flow channels 4c of the first flow paths 2c and the flow channels 5c of the second flow paths 3c form each circular ring-shaped flow paths 2c, 4c which, starting from the inside to the outside, are disposed adjacently and alternatingly as circular rings.

[0061] The essential difference from the device 1b of FIG. 2 is consequently that in the direction of the radius of the device 1c the first flow paths 2c as well as also the second flow paths 3c are each developed as circular rings with the width of a flow channel 4c, 5c, i.e. formed of a flow channel 4c, 5c. Each first flow path 2c is therewith in each instance encompassed by a second flow path 3c. The first flow path 2c located at the outer radius can, furthermore, be encompassed by a second flow path 3c, which is not shown in FIG. 3a.

[0062] On the outside as well as also on the inside, the flow channels 5c of the second flow paths 3c are in direct thermal contact with a flow channel 4c of the first flow paths 2c. The flow channels 4c, 5c, disposed adjacently in the direction of the radius of device 1c, of a type of flow path 2b, 3b are disposed such that they are not in contact with one another. The terms outside and inside always refer to the outer wall of the flow channels 4c, 5c depending on the radius of the device 1c.

[0063] FIG. 3b depicts a detailed view of the device 1c of FIG. 3a. By forming constant wall thicknesses and constant numbers of flow channels 4c, 5c either overlappings of the walls of the flow channels 4c, 5c occur or undesirable as well as unused interspaces between adjacent flow channels 4c, 5c develop. To the interspaces no fluid for heat exchange is applied and, as potential insulation, would affect and impair the heat transfer. Due to the specified pressure loading, the wall thicknesses are predetermined.

[0064] Maintaining the flow channels 5c, circular in cross section, of the second flow paths 3c, the flow channels 4c of the first flow paths 2c have to be adapted.

[0065] FIG. 3c depicts a detailed view of a device 1c with a cross section with circular flow channels 5c of the second flow paths 3c as well as, by example, a flow channel 4c of a first flow path 2c adapted to the interspaces between the second flow paths 3c.

[0066] At the contact sides with the flow channels 5c, the wall of flow channel 4c is herein adapted to the wall of the flow channels 5c and formed concavely such that the walls of the adjacently disposed flow channels 4c, 5c are fully in contact over their entire area. The radii of the outsides of the walls of the flow channels 4c, 5c are identical.

[0067] The walls of flow channels 4c at the contact sides with one another, i.e. in the circumferential direction, are planar and are also fully in contact with one another over their entire surface. The planar walls are each preferably oriented in the direction of the radius of device 1c.

[0068] When operating the device lc as internal heat exchanger of a refrigerant circuit, the flow channels 4c, adapted in cross section, of the first flow paths 2c are passed through by refrigerant at low pressure level and the circular flow channels 5c of the second flow paths 3c by refrigerant at high pressure level.

[0069] Herein, furthermore, the disposition of the flow channels 4c, 5c of device 1c according to FIG. 3c, as refrigerant flow channels in direct thermal contact with the refrigerant at high pressure level and the refrigerant of low pressure level, is to be preferred to the disposition of the flow channels 4b, 5b of device 1b according to FIG. 2 in a double row of the second flow channels 5b for the high pressure flow.

[0070] The devices 1a, 1b, 1c according to FIG. 1a to 1e and FIG. 2 as well as 3a to 3c can be implemented such that the first flow paths 2a, 2b, 2c as well as also the second flow paths 3a, 3b, 3c are each implemented as one integral element, which at the assembly of the device 1a, 1b, 1c are connected with one another as integral elements, in particular are plugged one into the other.

[0071] In FIG. 4 is depicted in cross section a device 1d for heat exchange with first and second flow paths 2d, 3d, coaxially disposed with respect to one another, with flow paths 2d, 3d formed of a circular, centrally disposed flow channel 4d and rectangular flow channels 4d, 5d, which flow paths 2d, 3d are, from the inside out, disposed adjacently as circular rings. Only the flow channel 2d in the center of the device 1d has a circular flow cross-section.

[0072] The device 1d is comprised of several circular cylindrical tubes disposed coaxially, wherein the flow paths 2d, 3d, from the inside out, are in each instance disposed such they are alternatingly adjacent. Between the adjacent tubes are developed fins or webs distributed uniformly over the circumference. The fins or webs, disposed in the direction of the radius of device ld, divide the flow paths 2d, 3d into the flow channels 4d, 5d, each of which is delimited in the circumferential direction by a tube wall and in the direction of the radius by a fin.

[0073] In comparison with the devices 1a, 1b, 1c according to FIG. 1 to 3, in which each flow channel 4a, 4b, 4c, 5a, 5b, 5c is delimited by its own wall and the walls of adjacently disposed flow channels 4a, 4b, 4c, 5a, 5b, 5c are in contact on one another, the flow channels 4d, 5d of device 1d of FIG. 4 have walls which delimit the flow channels 4d, 5d on both sides. Thus one wall separates flow channels 4d, 5d either of a first flow path 2d or of a second flow path 3d or it separates the flow channels 4d, 5d of different flow paths 2d, 3d from one another.

[0074] FIG. 5 depicts in perspective view a device 1e in cross section for heat exchange with first and second flow paths 2e, 3e, coaxially disposed with respect to one another, with the flow paths 2e, 3e implemented as a circular flow channel 4e and partial circular ring-shaped flow channels 4e, 5e which, from the inside out, are disposed adjacently as circular rings. Only the flow channel 4d, disposed in the center of device 1e has a circular flow cross section.

[0075] The essential difference from the device 1d of FIG. 4 consists in the form of the cross sections of the partial circular ring-shaped flow channels 4e, 5e being curved and elongated about the center axis of the circular cylindrical device 1d. Herein the four fins, disposed between the several circular cylindrically tubes that are coaxial with respect to one another and adjacent, are distributed uniformly over the circumference such that each flow channel 4e, 5e, with the exception of the flow channel 4e in the center, describes a quarter circular ring.

[0076] The embodiments of the devices 1d, 1e according to FIGS. 4 and 5 are also scalable, wherein in particular the disposition or the number of flow paths 2d, 2e, 3d, 3e are varied.

[0077] To distribute the fluid mass flow, between which the heat is to be transferred, for example when operating the device 1a, 1b, 1c, 1d, 1e as internal heat exchanger of a refrigerant circuit, between the refrigerant mass flows at high-pressure level and at low-pressure level, onto the individual flow channels 4a, 4b, 4c, 4d, 4e, 5a, 5b, 5c, 5d, 5e and to combine them again after they have passed through the device 1a, 1b, 1c, 1d, 1e, connection components are to be provided.

[0078] FIG. 6a to 6e depict each a configuration of devices 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i for heat exchange with first and second flow paths 2f, 2g, 2h, 2i, 3f, 3g, 3h, 3i, disposed coaxially with respect to one another, and each with either a connection element 6, 6f for the first flow path 2f and a connection element 7, 7f for the second flow path 3f or a combination connection element 11g, 11h, 11i.

[0079] The connection elements 6, 6f, 7, 7f, and the combination connection elements 11g, 11h, 11i, respectively, are each connected with one another and with the device 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i for example by means of adhesion, deforming, friction welding or welding. The connection elements 6, 6f, 7, 7f or the combination connection elements 11g, 11h, 11i advantageously comprise peanut fittings as connection elements to the connection lines.

[0080] As shown in FIGS. 6a and 6b at each of the front faces in the axial, and thus in the longitudinal, direction of the device 1a, 1b, 1c, 1d, 1e, if one connection element 6, 6f for the first flow path 2f is disposed. Between the particular front face of device 1a, 1b, 1c, 1d, 1e, 1f and the connection element 6, 6f for the first flow path, moreover, a connection element 7, 7f for the second flow path 3f is to be provided.

[0081] Depending on the direction of flow, the first fluid mass flow flowing into the first flow paths 2f is conducted through the connection element 6, 6f to the connection element 7, 7f and in the connection element 7, 7f distributed onto the flow channels 4f of the first flow paths 2f or the first fluid mass flow flowing out of the flow channels 4f of the first flow paths 2f is conducted through the connection element 7, 7f to the connection element 6, 6f and is mixed in the connection element 6, 6f. The connection element 6, 6f is connected with a connection line, not shown, to conduct the first fluid mass flow. Depending on the direction of flow, the second fluid mass flow flowing into the second flow paths 3f is distributed in the connection element 7, 7f onto the flow channels 5f of the second flow paths 3f or the second fluid mass flow flowing out of the flow channels 5f of the second flow paths 3f is conducted through the connection element 7, 7f and is mixed in a connection line 8 for conducting the second fluid mass flow. The connection line 8 is connected with the connection element 7, 7f.

[0082] FIG. 6b depicts in perspective view a device if in a cross section for heat exchange with first and second flow paths 2f, 3f, coaxially disposed with respect to one another, with flow channels 4f, implemented of honeycomb-shaped, in particular hexagonal, and specifically developed as hexagons, of the first flow paths 2f and circularly formed flow channels 5f of the second flow paths 3f.

[0083] The essential differences from the device 1e of FIG. 5 are the developments of the shapes of the cross sections as well as the disposition of the flow channels 4f, 5f, wherein the flow channels 4f are aligned as seven honeycombs with six individual honeycombs disposed uniformly about a single honeycomb in the center. The twelve fins formed between the honeycombs are herein distributed uniformly over the circumference. In terms of shape and dimension the honeycombs have identical flow cross sections. In the interspaces between each two of the six outer honeycombs and the outer diameter of device 1f the flow channels 5f are developed with the circular flow cross sections which are also uniformly distributed over the circumference.

[0084] At its core the connection element 7f has honeycomb-shaped connection flow channels 9f, which are developed and disposed such as to continue the flow channels 4f of the first flow paths 2f in the longitudinal direction L. The front faces in contact with one another of the device 1f and of the connection element 7f are identical in size and disposition of the honeycomb-shaped flow channels 4f and of the connection flow channels 9f, such that the flow channels 4f are extended through the connection element 7f up to the connection element 6f. Starting from the front face oriented toward the device 1f, the connection flow channels 9f taper on the way through the connection element 7f. In the connection element 6f the first fluid is distributed or mixed, depending on the direction of flow.

[0085] About the connection flow channels 9f disposed in the core a ring channel is realized as connection flow channel 10f of the second flow paths 3f, which ring channel is open in the direction toward the front face of the connection element 7f and encompasses, together with the circular flow channels 5f of the second flow paths 3f, a common volume. At the front faces of the device If and of connection element 7f the flow paths 3f open out into the common ring channel. The ring channel, in turn, is provided with an outlet opening which is disposed substantially perpendicularly to the longitudinal direction L and into which leads the connection line, not shown. In the ring channel of connection element 7f the second fluid is distributed or mixed, depending on the direction of flow.

[0086] FIG. 6c depicts a perspective view of a device 1g in cross section for heat exchange with first and second flow paths 2g, 3g, disposed coaxially with respect to one another, with circularly implemented flow channels 4g, 5g of the first and the second flow paths 2g, 3g as well as rectangularly implemented flow channels 4g of the first flow paths 2g.

[0087] Similarly to the device 1d of FIG. 4, the device 1g is implemented of several, in particular two, coaxial circular cylindrical tubes, wherein the flow paths 2g, 3g, from the inside out, are disposed such that they are alternatingly adjacent. Between the adjacent tubes fins, uniformly distributed over the circumference, are implemented. The fins, disposed in the direction of the radius of the device 1g, distribute the flow paths 2g, 3g onto the flow channels 4g, 5g, which are each delimited in the circumferential direction by a tube wall and in the direction of the radius by a fin.

[0088] In contrast to the device 1d of FIG. 4, the walls forming the tube wall as well as also the walls forming the fins in the longitudinal direction are also provided with circular flow channels 4g, 5g. While within the tube proper and in the circular flow channels 5g developed in the fins, the first fluid flows through the flow channels 4g of the first flow paths 2g, the circular flow channels 5g, formed within the tube walls, of the second flow paths 3g are charged with the second fluid.

[0089] In the longitudinal direction L the combination connection element 11g comprises continuous connection flow channels 9g, which are implemented and disposed such that they continue the flow channels 4g of the first flow paths 2g. In the proximity of the fins of device 1g the combination connection element 11g is developed with webs which extend from the outer wall in the direction of the radius up to the height of the wall of the inner tube and, in the proximity of the center, in particular in the proximity of the inner tube as a first flow path 2g, leave open the flow path 2g.

[0090] The webs are disposed on the front faces, oriented toward one another, of the device 1g and of the combination connection element 11g spaced apart from the fins of the device 1g such that the flow channels 4g developed in the fins, also open out into the volume left open by the webs. The first fluid flows substantially in the longitudinal direction L through the combination connection element 11g and, depending on the direction of flow, is distributed onto the flow channels 4g or the first fluid, flowing through the flow channels 4g, is at least partially mixed in the combination connection element 11g, flows subsequently through the combination connection element 11g and is lastly mixed after the webs.

[0091] The combination connection element 11g comprises about the connection flow channels 9g, disposed in the core, as well as at the ends of the webs at the height of the wall of the inner tube, a ring channel as the connection flow channels 10g of the second flow paths 3g, which are open in the direction toward the front face of the combination connection element 11g and, through channels formed in the webs encompass together with the circular flow channels 5g of the second flow paths 3g of the device 1g, a common volume. The flow paths 3g, developed in the wall of the inner tube, open at the front faces of the device 1g and of the combination connection element 11g out into an inner ring channel and the flow paths 3g developed in the wall of the outer tube open at the front faces of the device 1g and of the combination connection element 11g out into an outer ring channel. The inner ring channel and the outer ring channel are fluidically connected with one another via the channels developed in the webs. The outer ring channel, in turn, is provided with an outlet opening which is oriented substantially perpendicularly to the longitudinal direction L and into which lead connection lines, not shown. In the ring channels of the combination connection element 11g the second fluid is either distributed or mixed depending on the direction of flow.

[0092] FIG. 6d depicts in perspective view a device 1h in a cross section for heat exchange with first and second flow paths 2h, 3h, disposed coaxially with respect to one another, with flow channels 5h, developed circularly, of the second flow paths 3h as well as rectangularly developed flow channels 4h of the first flow paths 2h.

[0093] In contrast to the device 1g of FIG. 6c, the flow channels 5h, implemented circularly in the tube walls and the fins, as the second flow paths 3h are charged with the second fluid while within the tube proper the first fluid flows through the flow channels 4h of the first flow paths 2h.

[0094] The combination connection element 11h in a cross section comprises in its core a central circular connection flow channel 9h and rectangular connection flow channels 9h disposed about the central connection flow channel 9h, which are developed and disposed such that they continue the flow channels 4h of the first flow paths 2h in the longitudinal direction L. The front faces of the device 1h and of the combination connection element 11h in contact with one another are identical in terms of size and disposition of the flow channels 4h and connection flow channels 9h or they are at least nearly identical, such that the flow channels 4h are extended into the combination connection element 11h. The connection flow channels 9h end within the combination connection element 11h and open out into a common volume. In the combination connection element 11h the first fluid is distributed or mixed depending on the direction of flow. In the proximities of the fins of device 1h the combination connection element 11h is provided with webs which extend from the outer wall in the direction of the radius up to a circular ring disposed in the proximity of the wall of the inner tube of the device 1h. In the proximity of the inner tube the circular ring comprises a connection flow channel 9h with circular flow cross section as a first flow path 2h. At the front faces of the device 1h and of the combination connection element 11h the webs and the circular ring are in contact on the fins and the inner tube of the device 1h.

[0095] The combination connection element 11h comprises one ring channel each about the connection flow channels 9h, disposed in the core, as well as in the interior of the circular ring as connection flow channels 10h of the second flow paths 3h, which, like the webs, are open in the direction of the front face of the combination connection element 11h and, with the channels developed in the webs and the circular flow channels 5h of the second flow paths 3h of the device 1h, encompass a common volume. The flow paths 3h developed in the wall of the inner tube open at the front faces of the device 1h and of the combination connection element 11h out into an inner ring channel and the flow paths 3h developed in the wall of the outer tube, open at the front faces of the device 1h and of the combination connection element 11h out into an outer ring channel. The flow paths 3h developed in the fins open each at the front faces of device 1h and of the combination connection element 11g out into a channel developed in a web.

[0096] The inner ring channel and the outer ring channel are, moreover, fluidically connected with one another across the channels developed in the webs. The outer ring channel is provided with an outlet opening which is oriented substantially perpendicularly to the longitudinal direction L and into which the connection line, not shown, opens out. In the ring channels and in the channels developed in the webs of the combination connection element 11h the second fluid is distributed or mixed depending on the direction of flow.

[0097] FIG. 6e depicts in perspective view a device 1i in cross section for heat exchange with first and second flow paths 2i, 3i disposed coaxially with respect to one another, with flow paths 2i, 3i, developed with circular flow channel 4i and partial circular ring-shaped flow channels 4i, 5i, which, from the inside out, are disposed adjacently as circular rings. Only the flow channel 2i located in the center of the device 1i has a circular flow cross section.

[0098] In contrast to the device 1e of FIG. 5, three flow paths 2i, 3i are developed instead of two flow paths 2e, 3e disposed coaxially with respect to one another and disposed about the inner circular flow cross section as well as developed of partial circular ring-shaped flow channels 4e, 5e.

[0099] The combination connection element 11i corresponds substantially to the combination connection element 11h of FIG. 6d. The essential difference of the combination connection element 11h, 11i lies in the implementation of the webs which are closed in the direction of the front face of the combination connection element 11i and only form fluidic connections between the ring channels. The webs, moreover, at the front faces facing one another of the device 1i and of the combination connection elements 11i are not absolutely in contact on the fins and the inner tube of the device 1i.

[0100] The devices 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i are in particular directed at heat exchangers developed as coaxial tube heat exchangers, wherein the utilized mechanisms, materials and designs are also applicable to other types of heat exchangers.

[0101] The devices 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i permit their employment as internal heat exchangers of a refrigerant circuit which is employable for diverse refrigerants such as R1234yf, R1234ze, R134a, R290, R600a, R600, R717, R744, R32, R152a, R1270, R1150 and their mixtures.

LIST OF REFERENCE SYMBOLS

[0102] 1a, 1b, 1c, 1c, 1d, 1e, 1f, 1g, 1h, 1i Device

[0103] 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i First flow path

[0104] 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i Second flow path

[0105] 4a, 4b, 4c, 4c, 4d, 4e, 4f, 4g, 4h, 4i Flow channels first flow path

[0106] 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i Flow channels second flow path

[0107] 6, 6f Connection element first flow path

[0108] 7, 7f Connection element second flow path

[0109] 8 Connection line second fluid

[0110] 9f, 9g, 9h, 9i Connection flow channel first flow path

[0111] 10f, 10g, 10h, 10i Connection flow channel second flow path

[0112] 11g, 11h, 11i Combination connection element

[0113] L Longitudinal direction