Heat exchangers, especially tube bundle heat exchangers, for installation in a rotor with a rotating axis

Description

[0001] The invention relates to a heat exchanger, in particular a tube bundle heat exchanger, for use with a rotor having a rotational axis, comprising: first heat exchange channels for conducting a first heat exchange medium, in particular a liquid, second heat exchange channels for conducting a second heat exchange medium, in particular a gas, preferably a noble gas, wherein the second heat exchange channels, based on the assembled state of use of the heat exchanger, have at least one inner heat exchange channel located closer to the axis of rotation and one outer heat exchange channel further away from the axis of rotation, a distribution element, widened, preferably conically widened, as seen in the flow direction of the second heat exchange medium, for supplying the second heat exchange medium from an inlet opening of the distribution element into inflow openings of the second heat exchange channels, and a tapered, preferably substantially conically tapered, as seen in the flow direction of the second heat exchange medium,Converging element for discharging the second heat exchange medium from outflow openings of the second heat exchange channels into an outlet opening of the converging element.

[0002] Furthermore, the invention relates to a rotor, in particular a rotary heat pump, comprising: a rotation axis, a heat exchanger.

[0003] Finally, the invention relates to a method for heat exchange between a first heat exchange medium, in particular a liquid, and a second heat exchange medium, in particular a gas, preferably a noble gas, in the interior of a rotor, comprising the steps: Rotating the rotor about a rotational axis, guiding the first heat exchange medium along first heat exchange channels of a heat exchanger, guiding a second heat exchange medium along second heat exchange channels of the heat exchanger at different distances from the rotational axis of the rotor.

[0004] WO2015 / 103656 discloses a rotary heat pump in which the centrifugal acceleration of the rotor is used to generate different pressure and temperature levels. High-temperature heat is extracted from the compressed working fluid, and comparatively low-temperature heat is added to the expanded working fluid. For this purpose, the rotary heat pump has internal heat exchangers and external heat exchangers arranged essentially parallel to the rotor's rotational axis. The internal heat exchangers are designed for heat exchange at lower temperatures, while the external heat exchangers are designed for heat exchange at higher temperatures.

[0005] In addition, shell-and-tube heat exchangers are often used in stationary applications. The working fluid flows through a bundle of tubes arranged within a cylindrical casing. The heat exchange medium flows through the casing space in loops formed by baffles. This type of heat exchanger promises particularly good heat transfer between the two media. In stationary applications of such shell-and-tube heat exchangers, the incoming flow of the working fluid is fanned out symmetrically to the main flow direction to distribute the working fluid accordingly among the individual tubes.

[0006] However, when attempting to use the known tube bundle heat exchangers in a rotor, especially in a rotary heat pump, it has been shown that the heat transfer between the media falls significantly short of expectations.

[0007] The general state of the art is further illustrated by GB 1 383 690 A and CH 576 615 A5.

[0008] The present invention therefore aims to alleviate or eliminate the disadvantages of the prior art. The invention preferably aims to create a heat exchanger that exhibits high efficiency when used in a rotor.

[0009] This object is achieved by a heat exchanger according to claim 1, a rotor according to claim 8 and a method according to claim 13. Preferred embodiments are specified in the dependent claims.

[0010] According to the invention, a device for equalizing the flow through the second heat exchange channels is provided. This device comprises a throttle element designed to throttle to different degrees an inner flow of the second heat exchange medium passing through the inner of the second heat exchange channels and an outer flow of the second heat exchange medium passing through the outer of the second heat exchange channels between the inlet opening of the dividing element and the outlet opening of the merging element.

[0011] For the purposes of this disclosure, the location and direction specifications refer to the intended use of the heat exchanger as part of a rotor. "Front" and "rear" refer to the flow direction of the second heat exchange medium. "Radial" and "axial" refer to the rotor's axis of rotation. "Inside" means closer to the rotor's axis of rotation. "Outside" means farther from the axis of rotation. The distances refer to the radial distances from the axis of rotation.

[0012] Thus, the invention is based on the surprising discovery that the heat exchanger cannot be operated effectively under the effect of centrifugal acceleration by uniformly dividing the second heat exchange medium. The invention solves this problem by at least partially, preferably substantially completely, compensating the different pressure differences of the partial flows of the second heat exchange medium flowing at different distances from the axis of rotation between the inlet opening of the dividing element and the outlet opening of the merging element. This advantageously ensures that the second heat exchange channels are flowed through substantially uniformly.

[0013] Comprehensive flow analyses have shown that the main reason for the different pressure differences between the partial flows is that the outer flow first flows outwards in the dividing element and is compressed due to centrifugal force, before the outer flow exchanges heat with the first heat exchange medium along the outer side of the second heat exchange channels and then flows inwards in the merging element towards the outlet opening and is expanded in the process; for the inner flow, the sequence is reversed, as the inner flow first flows inwards in the dividing element and is expanded due to centrifugal force, then exchanges heat with the first heat exchange medium along the inner side of the second heat exchange channels before the inner flow is guided outwards in the merging element towards the outlet opening and is compressed in the process.

[0014] When the second heat exchange medium in the second heat exchange channels releases heat to the first heat exchange medium, the pressure difference arises from the fact that compression first occurs at a low density before the heat exchange, namely from the collected inflow of the second heat exchange medium via the inlet opening to the inflow opening of the outer heat exchange channel, then heat removal takes place in the outer heat exchange channel, whereby the temperature of the second heat exchange medium drops and thus - with an essentially isobaric heat exchange - the density increases; then the second heat exchange medium expands again with a comparatively high density, namely from the outflow opening of the outer heat exchange channel to the collection of the second heat exchange medium at the outlet opening.Because the second heat exchange medium compresses at low density (low pressure difference) and expands at high density (higher pressure difference), an additional pressure difference remains when considering this flow path, which is required when flowing through the outer heat exchange channel. This would result in the second heat exchange medium preferring the inner of the second heat exchange channels. If heat is supplied to the second heat exchange medium through the first heat exchange medium, the opposite is true. In this case, the second heat exchange medium would prefer the outer of the second heat exchange channels.

[0015] The invention now aims to compensate for the additional pressure difference by means of the throttle element, which throttles the outer and inner flow to different degrees in a section between the inlet opening of the dividing element and the outlet opening of the merging element, i.e. causes different flow resistances.

[0016] If heat is transferred from the second heat exchange medium to the first heat exchange medium in the second heat exchange channels, the throttle device is designed to throttle the inner flow more strongly than the outer flow.

[0017] If heat is supplied from the first heat exchange medium to the second heat exchange medium in the second heat exchange channels, the throttle device is designed to throttle the outer flow more strongly than the inner flow.

[0018] Thus, the throttle device is configured to asymmetrically throttle the flow of the second heat exchange medium with respect to the center or symmetry axis of the heat exchanger. With the aid of the throttle device, the second heat exchange medium is subjected to essentially the same pressure differences as it flows through the heat exchanger from the inlet to the outlet opening. This advantageously ensures that the second heat exchange channels are flowed through essentially uniformly, so that the second heat exchange medium has essentially the same average flow velocity or essentially the same volume flow along the second heat exchange channels (provided that the second flow channels have, as preferred, the same flow cross-section).

[0019] In a preferred embodiment, the heat exchanger is designed as a tube bundle heat exchanger. The tube bundle heat exchanger has a tube bundle with a plurality of tubes, preferably each with a substantially circular cross-section, which enclose the second heat exchange channels. The tubes preferably extend parallel to one another. The tube bundle can be arranged within a preferably cylindrical housing. The first heat exchange medium is guided through first heat exchange channels which extend inside the housing. Deflection elements for the first heat exchange medium are preferably provided inside the housing. The deflection elements are preferably arranged substantially perpendicular to the tubes. The deflection elements preferably leave recesses free in the interior of the housing for the first heat exchange medium, wherein the recesses are preferably arranged alternately on opposite sides.As a result, the first heat exchange medium is guided in a loop-like manner through the interior of the housing, with the first heat exchange medium flowing in sections transversely to the tubes with the second heat exchange channels.

[0020] In a first preferred embodiment, the throttle device has a throttle orifice with throttle openings, wherein a throttle opening further away from the axis of rotation and a throttle opening closer to the axis of rotation are of different sizes. The throttle orifice can be arranged upstream of the inlet openings, in particular directly upstream of the inlet openings, or downstream of the outlet openings, in particular directly downstream of the outlet openings. In a design for heat dissipation from the second heat exchange medium, the throttle opening further away from the axis of rotation is larger than the throttle opening closer to the axis of rotation. In a design for heat supply to the second heat exchange medium, the throttle opening further away from the axis of rotation is smaller than the throttle opening closer to the axis of rotation. The advantage of this design of the throttle device is its simple construction.Furthermore, the heat exchanger can be set to a specific operating point by simply replacing the throttle plate.

[0021] Preferably, the throttle orifice is arranged upstream of the second heat exchange channels such that the second heat exchange medium is supplied to precisely one of the second heat exchange channels via the throttle openings. Alternatively, the throttle orifice can be arranged downstream of the second heat exchange channels such that the second heat exchange medium is discharged from each of the second heat exchange channels through precisely one throttle opening.

[0022] Preferred designs of the throttle orifice are described below, based on a design for heat dissipation from the second heat exchange medium along the second heat exchange channels. The principle can be applied accordingly to the case of heat supply to the second heat exchange medium if a stronger throttling is provided, here through smaller throttle openings, with the distance from the rotation axis extending outwards.

[0023] The throttle orifice preferably has at least one first throttle opening at a first distance from the axis of rotation and at least one second throttle opening at a second distance from the axis of rotation of the rotor, wherein the second distance is greater than the first distance and the second throttle opening is larger than the first throttle opening. The throttle orifice preferably has at least one third throttle opening at a third distance from the axis of rotation, which is greater than the second distance, wherein the at least one third throttle opening is larger than the at least one second throttle opening. The throttle orifice preferably has at least one fourth throttle opening at a fourth distance from the axis of rotation, which is greater than the third distance, wherein the at least one fourth throttle opening is larger than the at least one third throttle opening.Of course, the throttle orifice can have further throttle openings at greater distances from the axis of rotation of the rotor, with throttle openings further away from the axis of rotation being larger than throttle openings closer to the axis of rotation.

[0024] In a preferred embodiment, the heat exchanger has a plurality of rows of second heat exchange channels, wherein the second heat exchange channels of each row are each at substantially the same distance from the rotational axis of the rotor. Accordingly, the throttle orifice preferably has a plurality of rows, each with a plurality of throttle openings, wherein a row farther from the rotational axis and a row closer to the rotational axis have throttle openings of different sizes. In the case of heat dissipation, the row of throttle openings farther from the rotational axis has larger throttle openings than the row of throttle openings closer to the rotational axis.

[0025] Thus, a first row of first throttle openings, each substantially at the first distance from the axis of rotation, and a second row of second throttle openings, each substantially at the second distance from the axis of rotation, preferably also a third row of third throttle openings, each substantially at the third distance from the axis of rotation, preferably also a fourth row of fourth throttle openings, each substantially at the fourth distance from the axis of rotation, preferably also at least one further row of further throttle openings, each at a further distance from the axis of rotation, can be provided.

[0026] To enable the supply of the second heat exchange medium into the individual second heat exchange channels, the distribution element is arranged upstream of the second heat exchange channels (as viewed in the flow direction of the second heat exchange medium). This distribution element is widened, i.e., has an increasing cross-section, as viewed in the flow direction of the second heat exchange medium. The distribution element enables the flow of the second heat exchange medium to be divided at the inlet of the heat exchanger into the individual flows within the second heat exchange channels. The distribution element is preferably conically widened.

[0027] In a second preferred embodiment, a flow grid is arranged within the dividing element, wherein the flow grid has individual dividing channels widening in the flow direction, wherein the dividing channels each have a starting section and an end section.

[0028] In a second embodiment of the throttle device, the initial and / or final section of a distribution channel further away from the rotation axis and the initial and / or final section of a distribution channel closer to the rotation axis have different flow cross-sections. The advantage of this design is that the flow grid is generally useful for good distribution and flow guidance in order to keep pressure losses as low as possible. Advantageously, this flow grid can now also be designed as a throttle device, with which an asymmetric cross-sectional expansion is achieved in order to compensate for the different pressure differences depending on the distance from the rotation axis. The initial section connects to the inlet of the heat exchanger. The final section carries the second heat exchange medium to the inlet opening of the second heat exchange channel.In the case of heat dissipation from the second heat exchange medium to the first heat exchange medium, the initial and / or final section of the distribution channel further away from the axis of rotation has a larger flow cross-section than the initial and / or final section of the distribution channel closer to the axis of rotation.

[0029] Preferably, the flow grid has exactly one distribution channel per second heat exchange channel, so that the second heat exchange medium is supplied to exactly one of the second heat exchange channels via each distribution channel. The distribution channels are separated from one another by individual wall sections, with vertical and horizontal wall sections preferably being provided. The vertical wall sections serve, on the one hand, to ensure a uniform distribution in the tangential direction (whereby the problem of different pressures described above does not occur), but also have the advantage that the horizontal wall sections, which are provided for the radial distribution of the flow, are supported against deflection under the effect of centrifugal force.

[0030] Preferred designs of the flow grid are described below, based on a design for heat dissipation from the second heat exchange medium along the second heat exchange channels. The principle can be applied accordingly to the case of heat supply if a stronger throttling is provided with the distance from the rotation axis towards the outside.

[0031] Preferably, the flow grid has at least one first distribution channel at a first distance from the axis of rotation and at least one second distribution channel at a second distance from the axis of rotation of the rotor, wherein the second distance is greater than the first distance and the initial and / or end section of the second distribution channel has a larger flow cross-section than the initial and / or end section of the first distribution channel. Preferably, the flow grid has at least one third distribution channel at a third distance from the axis of rotation, wherein the third distance is greater than the second distance and the initial and / or end section of the third distribution channel has a larger flow cross-section than the initial and / or end section of the second distribution channel.Preferably, the flow grid has at least one fourth distribution channel at a fourth distance from the rotation axis, wherein the fourth distance is greater than the third distance, and the initial and / or final section of the fourth distribution channel has a larger flow cross-section than the initial and / or final section of the third distribution channel. Of course, the flow grid can have further distribution channels at further distances from the rotation axis, wherein the flow cross-section of the initial and / or final section increases with the distance from the rotation axis.

[0032] Preferably, the flow grid has at least a first row with a plurality of individual, i.e. separate, first distribution channels substantially at the first distance from the axis of rotation and a second row with a plurality of second distribution channels substantially at the second distance from the axis of rotation, preferably also a third row with a plurality of third distribution channels substantially at the third distance from the axis of rotation, preferably also a fourth row with a plurality of fourth distribution channels substantially at the fourth distance from the axis of rotation, preferably also further rows each with a plurality of further distribution channels.

[0033] In a first variant, the initial section of the distribution channel further away from the axis of rotation has a larger flow cross-section than the initial section of the distribution channel closer to the axis of rotation, wherein the end section of the distribution channel further away from the axis of rotation has substantially the same flow cross-section as the end section of the distribution channel closer to the axis of rotation. This embodiment is particularly advantageous for design reasons if the second heat exchange channels have the same flow cross-sections. Thus, in this variant, the second heat exchange medium can flow asymmetrically into the flow grid, wherein the flow cross-section during the inflow increases with the distance from the axis of rotation. The outflow from the flow grid, on the other hand, can be symmetrical, i.e. with substantially the same flow cross-section.

[0034] In a second variant, the end section of the distribution channel further away from the rotation axis has a larger flow cross-section than the end section of the distribution channel located closer to the rotation axis, with the initial section of the distribution channel further away from the rotation axis having essentially the same flow cross-section as the initial section of the distribution channel located closer to the rotation axis. This design is particularly simple in terms of construction. Thus, in this variant, the inflow into the flow grid can be symmetrical, but the outflow from the flow grid can be asymmetrical.

[0035] In a third variant, the initial and final sections of the distribution channel located further from the rotation axis each have a larger flow cross-section than the initial and final sections of the distribution channel located closer to the rotation axis. Thus, in this variant, both the inflow into and outflow from the flow grid can occur asymmetrically, i.e., with a larger flow cross-section with increasing distance from the rotation axis.

[0036] The asymmetrical distribution of the second heat exchange medium by means of the flow grid results in a near-axis flow of the second heat exchange medium, from the inlet into the heat exchanger to the outlet from the heat exchanger, flowing through a smaller flow cross-section than a far-axis flow of the second heat exchange medium, whereby the near-axis flow is subjected to a higher pressure drop than the far-axis flow. Thus, the pressure difference between the near-axis and far-axis second heat exchange channels is at least partially, preferably essentially completely, balanced.

[0037] Furthermore, a flow grid can be arranged within the converging element, wherein the flow grid within the converging element has individual converging channels tapering in the flow direction, wherein the converging channels each have a starting section (on the side of the outflow openings of the second heat exchange channels) and an end section (on the side facing away from the outflow openings). To form the throttle element, the starting and / or end section of a converging channel further away from the rotational axis and the starting and / or end section of a converging channel located closer to the rotational axis have different flow cross-sections.

[0038] In a third preferred embodiment, the device for equalizing the flow through the second heat exchange channels comprises turbulators, in particular spiral turbulators, within the second heat exchange channels, wherein a turbulator further away from the axis of rotation and a turbulator closer to the axis of rotation cause different pressure losses. In the case of heat dissipation from the second heat exchange medium along the second heat exchange channels, the turbulator further away from the axis of rotation causes a lower pressure loss than the turbulator closer to the axis of rotation.

[0039] For this purpose, the turbulator farther from the rotation axis and the turbulator closer to the rotation axis can have different spiral lengths. In the case of heat removal from the second heat exchange medium along the second heat exchange channels, the turbulator farther from the rotation axis can have a greater pitch than the turbulator closer to the rotation axis.

[0040] The advantage of the turbulators compared to the previously described embodiments of the throttle device is that not only can the pressure loss in the second heat exchange channels be adjusted differently with different distances to the axis of rotation in order to achieve a uniform flow through the second flow channels, but also the heat transfer is increased by increased turbulence during heat transfer.

[0041] In a fourth embodiment, the outer and inner second heat exchange channels have different flow cross-sections, in the case of pipes with circular cross-sections, different diameters, to form the throttle element.

[0042] In a preferred application, a rotor, in particular a rotary heat pump, is provided with the heat exchanger in one of the previously described embodiments.

[0043] In a first preferred embodiment, a central or symmetry axis of the heat exchanger is arranged at a radial distance from the axis of rotation, ie with an axial offset.

[0044] In a second preferred embodiment, the center axis of the heat exchanger is arranged substantially in line with the rotation axis. In this case, too, the second heat exchange channels are at different distances from the rotation axis.

[0045] In the rotor, the second heat exchange channels preferably extend substantially parallel and at different radial distances from the axis of rotation. The first heat exchange channels can, as is common in shell-and-tube heat exchangers, extend in sections substantially perpendicular to the second heat exchange channels.

[0046] In a preferred embodiment, the rotor has a compressor unit in which the second heat exchange medium is guided away from the axis of rotation to increase the pressure due to the centrifugal force, and an expansion unit in which the second heat exchange medium is guided towards the axis of rotation to reduce the pressure due to the centrifugal force.

[0047] In this design of the rotor, at least one heat exchanger is preferably provided that is internal relative to the rotational axis and at least one heat exchanger that is external relative to the rotational axis. Depending on the design, the external heat exchanger and / or the internal heat exchanger can be designed according to one of the above embodiments of the heat exchanger.

[0048] In the method according to the invention for heat exchange between a first heat exchange medium, in particular a liquid, and a second heat exchange medium, in particular a gas, preferably a noble gas, in the interior of a rotor, comprising the steps: Rotating the rotor about a rotational axis, guiding the first heat exchange medium along first heat exchange channels of a heat exchanger, guiding the second heat exchange medium along second heat exchange channels of the heat exchanger at different distances from the rotational axis of the rotor, equalizing the flow through the second heat exchange channels by differently throttling an inner flow of the second heat exchange medium closer to the rotational axis and an outer flow of the second heat exchange medium further away from the rotational axis.

[0049] In a preferred embodiment, heat is removed from the second to the first heat exchange medium along the second heat exchange channels, wherein the inner flow of the second heat exchange medium is throttled more than the outer flow of the second heat exchange medium.

[0050] The invention is explained below with reference to preferred embodiments which are illustrated in the drawings.

[0051] Fig. 1 shows a rotor 1, which in the embodiment shown is designed as a device for converting mechanical energy into thermal energy (and vice versa). This device is operated in particular as a rotary heat pump. The rotor 1 has a rotational axis 2, which is, for example, horizontal during operation, around which the rotor 1 is rotated with the aid of a motor (not shown). The rotor 1 has a compressor unit 3, in which a working medium is guided away from the rotational axis 2 due to centrifugal force to increase the pressure. In addition, the rotor 1 has an expansion unit 4, in which the working medium is guided towards the rotational axis 2 to reduce the pressure. The working medium is preferably guided in a closed circuit within the rotor 1. In addition, the rotor 1 has several internal heat exchangers 5 (low-pressure heat exchangers) and several external heat exchangers 6 (high-pressure heat exchangers).In the inner 5 and outer heat exchangers 6, heat exchange takes place between a first heat exchange medium and a second heat exchange medium, namely the working fluid. Such a device—but with different types of heat exchangers—is shown, for example, in WO2015 / 103656.

[0052] Fig. 2A shows a heat exchanger 7, also referred to as a heat transferor, in an embodiment which can be implemented in the inner 5 and / or the outer heat exchanger 6. In the following, the heat exchanger 7 is described by way of example for use as an outer heat exchanger 6, ie as a high-pressure heat exchanger. The heat exchanger 7 has an inlet element 8, via which the second heat exchange medium, ie the working medium, is supplied to the heat exchanger 7, and an outlet element 9, via which the second heat exchange medium leaves the heat exchanger 7.

[0053] In the embodiment shown, the heat exchanger 7 is designed as a tube bundle heat exchanger. The tube bundle heat exchanger has a cylindrical housing 10 in which a tube bundle is arranged. The tube bundle has elongated tubes 11 arranged parallel to one another and spaced apart in the radial direction and in the circumferential direction. Inside, the tubes 11 enclose second heat exchange channels 12 for the second heat exchange medium. The tubes 11 are each held at opposite ends in a tube sheet in the form of a base plate 11A (see. Fig. 2B ). The first heat exchange medium is fed into the interior of the housing 10 via an inlet 13 and, after heat exchange with the second heat exchange medium, is discharged from the housing 10 via a discharge line 14. Inside the housing 10, the first heat exchange medium flows in first heat exchange channels 15, which are designed with the aid of deflection elements 16 such that the first heat exchange medium flows alternately in opposite directions transverse to the tubes 11, ie, in the position shown, alternately downwards and upwards. In between, the first heat exchange medium is deflected into the next channel by means of the deflection elements 16.

[0054] As from Fig. 2A As can also be seen, the heat exchanger 7 has, between the inlet element 8 and the inlet side of the housing 10, a dividing element 17 with an inlet opening 17A, which is widened in the flow direction of the second heat exchange medium. Furthermore, the heat exchanger 7 has, between the outlet element 9 and the outlet side of the housing 10, a converging element 18 with an outlet opening 18A for converging the individual flows of the second heat exchange medium after flowing through the second heat exchange channels 12. The converging element 18 tapers in the flow direction of the second heat exchange medium.

[0055] Fig. 2B shows a simplified version of the heat exchanger 7, with arrows illustrating the inflow and distribution of the gas to the individual second heat exchange channels 12 within the housing 10.

[0056] The design of the heat exchanger 7 as a shell-and-tube heat exchanger is fundamentally very advantageous for use with the rotor 1. However, it is essential that the second heat exchange channels 12 are flowed through evenly in order to effectively utilize the heat transfer surface.

[0057] As from Fig. 3 As can be seen, it would be obvious to divide the flow of the second heat exchange medium entering the heat exchanger 7, see arrow 20, evenly into the discrete second flow channels 12, ie the tube bundles, by fanning it out. For this purpose, a flow grid 21 can be arranged within the distribution element 17, which has individual distribution channels 22 that continuously widen along the flow grid 21. The distribution channels 22 are according to Fig. 3 identically designed to achieve an even distribution.

[0058] Surprisingly, however, it has been shown that when the rotor 1 rotates under high centrifugal acceleration, a number of phenomena occur that prevent uniform flow through the incoming flow of the second heat exchange medium by simply fanning out. The reason for this was identified as the different densities at the inlet and outlet of the second heat exchange medium, in this case the gas, at different radial distances from the center of rotation of the discrete second flow channels 12.

[0059] As from Fig. 4 As can be seen from a schematic representation of heat exchanger 7 when used as an external (high-pressure) heat exchanger 6, during operation, heat is transferred from the second heat exchange medium, hereinafter also referred to as gas, to the first heat exchange medium, hereinafter also referred to as liquid or water. On the right side, the inflow occurs at a relatively high temperature, and on the left side, the outflow occurs at a relatively low temperature after heat transfer. This results in a higher density on the outflow side than on the inflow side.

[0060] To illustrate the technical effect, the following assumptions and simplifications are made for a model calculation: Average radius to the rotation axis: 900 mm Radial extension of the heat exchanger 7 (from the innermost of the second heat exchange channels 12 to the outermost of the heat exchange channels 12): 100 mm Average pressure in the heat exchanger: 120 bar Average temperature: 400 K Gas: Krypton

[0061] If the flow of the gas, assumed to be ideal, i.e. without taking into account real gas properties, only takes place under the acceleration due to gravity, and the heat exchanger is aligned so that the acceleration due to gravity has the same direction as the centrifugal acceleration, then the pressure difference between the outermost flow channel and the innermost flow channel is 0.14 mbar and is not taken into account due to the minimal effect.

[0062] Fig. 5 shows a roughly calculated pressure difference between the flow channels ("outside" - arrow 23 in Fig. 4 ; "inside" - arrow 24 in Fig. 4 ) in revolutions per minute (rpm), whereby the effect of rotation on the heat exchanger 7 is illustrated. The radial distance of the outermost channel from the axis of rotation 2 is shown by arrow 25, the radial distance of the innermost channel from the axis of rotation 2 is shown by arrow 26. The main flow direction of the gas is shown by arrow 27. At a speed of rotation of the rotor 1 of 1800 rpm, this difference amounts to 0.46 bar and is therefore a factor of about 3300 greater (corresponding to the ratio of the accelerations) than under gravity. This means that, without any other measures, the gas prefers the inner channels, since the gas experiences an increase in pressure in the inner regions, whereas the gas through the outermost channel experiences a reduction in pressure. In addition, backflow can occur, so that the gas flows from right to left on the inside and from left to right on the outside.This results in more flow energy being required and a smaller effective heat exchanger surface being available, since largely only the inner area of ​​the heat exchanger is used.

[0063] Fig. 6 and Fig. 7 show a first embodiment of the heat exchanger 7 according to the invention for the case of the external heat exchanger 6, wherein only the differences from the preceding embodiments are described below.

[0064] In this embodiment, a device 30 is provided for equalizing the flow through the second heat exchange channels 12, with which different pressure differences of the second heat exchange medium are compensated, which are caused by the different radial distances of the second heat exchange channels 12 to the axis of rotation 2 of the rotor 2.

[0065] As a device 30 for equalizing the flow through the second heat exchange channels 12, a throttle device for differentially throttling the discrete second heat exchange channels 12 is provided in the illustrated embodiment. A flow of the second heat exchange medium located closer to the rotation axis 2, i.e., having a smaller radial distance, is throttled more severely than a flow of the second heat exchange medium located further away from the rotation axis 2, i.e., having a greater radial distance.

[0066] In the execution according to Fig. 6 and Fig. 7 The throttle device comprises a disc-shaped throttle orifice 31, which is circular in the flow direction of the second heat exchange medium, with a plurality of circular throttle openings 32, which are arranged directly in front of the inlet openings 29 of the second heat exchange channels 12. The throttle openings 32 are arranged in rows, with the diameters of the throttle openings 32 increasing from row to row outwards, i.e., away from the rotation axis 2. Within a row, the throttle openings 32 have the same diameter.

[0067] In the execution according to Fig. 8 An asymmetrically designed flow grid 21 (relative to the central axis 36 of the heat exchanger 7) is provided as a device 30 for equalizing the flow through the second heat exchange channels. The distribution channels 22 of the flow grid 21 each have a starting section 22A and an end section 22B. In the embodiment shown, the flow cross-section of the starting sections 22A increases with the distance from the rotation axis 2. The end sections 22B, however, have the same flow cross-sections. Extending between the starting sections 22A and the end sections 22B are central sections 22C, which provide a continuous transition from the starting sections 22A to the end sections 22B.

[0068] In the execution according to Fig. 9Spiral turbulators 33 are inserted into the second heat exchange channels 12. To form the device 30, various spiral turbulators 33 are provided, which cause lower pressure losses in the second heat exchange medium the further the spiral turbulators 33 are from the rotation axis 2. For this purpose, a spiral turbulator 33 located farther from the rotation axis 2 can have a greater spiral length (see arrow 34) than a turbulator 33 located closer to the rotation axis 2 (see arrow 35). List of reference numbers:

[0069] 1 Rotor 2 Rotation axis 3 Compressor unit 4 Expansion unit 5 Internal heat exchangers 6 External heat exchangers 7 Heat exchangers 8 Inlet element 9 Outlet element 10 Housing 11 Tubes 11A Tube sheet 12 Second heat exchange channels 13 Inlet 14 Outlet 15 First heat exchange channels 16 Deflection elements 17 Distribution element 17A Inlet opening 18A Outlet opening 18 Merging element 20 Arrow 21 Flow grid 22 Distribution channels 22A Initial section 22B Middle section 22C End section 23 Arrow 24 Arrow 25 Arrow 26 Arrow 27 Arrow 28 Outlet openings 29 Inlet openings 30 Device for equalizing the flow 31 Throttle orifice 32 Throttle openings 33 Turbulators 34 Arrow 35 Arrow 36 Central axis

Claims

1. A heat exchanger (7), in particular a shell-and-tube heat exchanger, for arrangement in a rotor (1) having an axis of rotation (2), comprising: first heat-exchange channels (15) for guiding a first heat-exchange medium, in particular a liquid; second heat-exchange channels (12) for guiding a second heat-exchange medium, in particular a gas, preferably a noble gas, wherein the second heat-exchange channels (12) comprise, in the assembled usage state, at least one inner heat-exchange channel, which is closer to the axis of rotation (2), and one outer heat-exchange channel, which is further away from the axis of rotation (2); a distribution element (17), which expands, preferably conically expands, in the direction of flow of the second heat-exchange medium for feeding the second heat-exchange medium from an entry opening (17A) in the distribution element (17) into inflow openings (29) in the second heat-exchange channels (12); a merger element (18), which tapers, preferably tapers substantially conically, in the direction of flow of the second heat-exchange medium for discharging the second heat-exchange medium from outflow openings (28) in the second heat-exchange channels (12) into an exit opening (18A) in the merger element(18), characterised by a device (30) for homogenising the flow through the second heat-exchange channels (12), comprising a throttle member for throttling, to different extents, an inner flow of the second heat-exchange medium that passes through the inner one of the second heat-exchange channels (12), and an outer flow of the second heat-exchange medium that passes through the outer one of the second heat-exchange channels (12) between the entry opening (17A) in the distribution element (17) and the exit opening (18A) in the merger element (18).

2. The heat exchanger (7) according to claim 1, characterised in that the throttle member comprises a throttle orifice plate (31) having throttle openings (32), preferably upstream of the inflow openings (29) or downstream of the outflow openings (28), wherein a throttle opening (32), which is further away from the axis of rotation (2), and a throttle opening (32), which is closer to the axis of rotation (2), are of different sizes.

3. The heat exchanger (7) according to claim 2, characterised in that the throttle orifice plate (31) comprises a plurality of rows each having a plurality of throttle openings (32), wherein a row, which is further away from the axis of rotation (2), and a row, which is closer to the axis of rotation (3), comprise throttle openings (32) of different sizes.

4. The heat exchanger (7) according to any one of claims 1 to 3, characterised in that the distribution element (17) comprises a flow grid (21) having individual distribution channels (22), which expand in the direction of flow of the second heat-exchange medium, wherein the distribution channels (22) each comprise an initial portion (22A) and an end portion (22B).

5. The heat exchanger (7) according to claim 4, characterised in that, in order to form the throttle member, the initial (22A) and / or end portion (22B) of a distribution channel (22), which is further away from the axis of rotation (2), and the initial (22A) and / or end portion (22B) of a distribution channel (22), which is closer to the axis of rotation (2), comprise different flow cross-sections.

6. The heat exchanger (7) according to any one of claims 1 to 5, characterised in that turbulators (33), in particular spiral turbulators, are provided within the second heat-exchange channels (12) in order to form the throttle member, wherein a turbulator (33), which is further away from the axis of rotation (2), and a turbulator (33), which is closer to the axis of rotation (2), cause different pressure losses.

7. The heat exchanger (7) according to claim 6, characterised in that the spiral turbulator (33), which is further away from the axis of rotation (2), and the spiral turbulator (33), which is closer to the axis of rotation (2), comprise different spiral lengths.

8. A rotor (1), in particular a rotary heat pump, comprising: an axis of rotation (2), a heat exchanger (7) according to any one of claims 1 to 7.

9. The rotor (1) according to claim 8, characterised in that the second heat-exchange channels (12) extend substantially parallel to the axis of rotation (2).

10. The rotor (1) according to claim 8 or 9, characterised by: a compressor unit (3) in which the second heat-exchange medium is guided away from the axis of rotation (2) in order to increase the pressure, an expansion unit (4) in which the second heat-exchange medium is guided towards the axis of rotation (2) in order to reduce pressure.

11. The rotor (1) according to any one of claims 8 to 10, characterised by: an inner heat exchanger (5) with respect to the axis of rotation (2) and an outer heat exchanger (6) with respect to the axis of rotation (2).

12. The rotor (1) according to claim 11, characterised in that the outer (6) heat exchanger (5) is designed according to any one of claims 1 to 7, wherein the throttle member is configured to throttle the inner flow of the second heat-exchange medium passing through the inner heat-exchange channel to a greater extent than the outer flow of the second heat-exchange medium passing through the outer heat-exchange channel.

13. A method for exchanging heat between a first heat-exchange medium, in particular a liquid, and a second heat-exchange medium, in particular a gas, preferably a noble gas, inside a rotor (1), comprising the steps of: rotating the rotor (1) around an axis of rotation (2); guiding the first heat-exchange medium along first heat-exchange channels (15) of a heat exchanger (7); guiding a second heat-exchange medium along second heat-exchange channels (12) of the heat exchanger (7) at different distances from the axis of rotation (2) of the rotor (1), wherein a heat exchange takes place between the first and the second heat-exchange medium along the first (15) and the second heat-exchange channels (12), characterised by homogenising the flow through the second heat-exchange channels (12) by throttling, to different extents, of an inner flow of the second heat-exchange medium, which is closer to the axis of rotation (2), and an outer flow of the second heat-exchange medium, which is further away from the axis of rotation (2).