Heat Exchange Means with an Elastocaloric Element, Which Surrounds a Fluid Line

Abstract

A heat exchanger is configured to surround a fluid line which guides a heat transport fluid. The heat exchanger includes at least one elastocaloric element, which is connected to the fluid line, and at least one actuator, which acts on the elastocaloric element and is configured so as, when actuated, to exert a force on the at least one elastocaloric elements in order to deform the at least one elastocaloric element. The heat exchanger further includes at least one fastening element, which is configured to fasten the heat exchanger to the fluid line.

Claims

1. A heat exchanger configured to surround a fluid line that guides a heat transport fluid, the heat exchanger comprising: at least one elastocaloric element configured to be connected to or arranged on the fluid line; at least one actuator operatively connected to the elastocaloric element and configured such that, when actuated, the at least one actuator exerts a force on the at least one elastocaloric element so as to deform the at least one elastocaloric element; and at least one fastening element configured to fasten the heat exchanger to the fluid line.

2. The heat exchanger according to claim 1, wherein: the at least one actuator includes two actuators arranged on one elastocaloric element of the at least one elastocaloric elements in a longitudinal direction of the fluid line, and the two actuators are configured such that, when actuated, the two actuators exert the force on the one elastocaloric element so as to deform the one elastocaloric element.

3. The heat exchanger according to claim 2, wherein each actuator of the two actuators is connected to and held by one fastening element of the at least one fastening element, the one fastening element arranged in the longitudinal direction of the fluid line.

4. The heat exchanger according to claim 2, wherein the at least one actuator includes at least two actuators that divide a common fastening element of the at least one fastening element, and the at least two actuators are held by the common fastening element.

5. The heat exchanger according to claim 1, wherein the at least one elastocaloric element, the at least one actuator, and the at least one fastening element are each designed in the form of an annular disk and configured to be arranged annularly around the fluid line.

6. The heat exchanger according to claim 1, further comprising: a heat-conducting layer configured to thermally connect the at least one elastocaloric element to the fluid line.

7. The heat exchanger according to claim 1, further comprising: a heat-insulating layer that thermally insulates at least the at least one actuator from the at least one elastocaloric element and from the fluid line.

8. A heat exchange system, comprising: a fluid line; at least one heat exchanger comprising: at least one elastocaloric element connected to or arranged on the fluid line; at least one actuator operatively connected to the elastocaloric element and configured such that, when actuated, the at least one actuator exerts a force on the at least one elastocaloric element so as to deform the at least one elastocaloric element; and at least one fastening element that fastens the heat exchanger to the fluid line; and an electronic control unit configured to control the at least one actuator of the at least one heat exchanger.

9. The heat exchange system according to claim 8, wherein: the at least one heat exchanger includes a plurality of heat exchangers arranged on the fluid line, and the electronic control unit is configured to control the at least one actuator of each of the plurality of heat exchangers.

10. The heat exchange system according to claim 9, wherein the plurality of heat exchangers are connected to one another in the manner of a cascade.

11. The heat exchange system according to claim 9, wherein the electronic control unit is configured to control the at least one actuator of the plurality of heat exchangers successively in time depending on flow properties of a heat transport fluid in the fluid line.

12. The heat exchange system according to claim 8, further comprising: a reservoir that supplies heat transport fluid to the fluid line; and at least one return line through which heat transport fluid is guided out of the fluid line to the reservoir.

13. The heat exchange system according to claim 8, further comprising: at least one internal return line which connects an end of the fluid line to a beginning of the fluid line, wherein the at least one heat exchanger is arranged between the beginning of the fluid line and the end of the fluid line.

14. The heat exchange system according to claim 8, further comprising: at least one first valve arranged at a beginning of the fluid line; and at least one second valve arranged at an end of the fluid line.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Exemplary embodiments of the disclosure are illustrated in the drawings and explained in more detail in the description below.

[0030] FIG. 1 shows an isometric illustration of a heat exchange means according to a first embodiment of the disclosure with an elastocaloric element.

[0031] FIG. 2 shows a sectional illustration of the heat exchange means from FIG. 1.

[0032] FIG. 3 shows an isometric illustration of the heat exchange means according to a second embodiment of the disclosure with a plurality of elastocaloric elements.

[0033] FIG. 4 shows a schematic isometric illustration of part of a heat exchange system according to one embodiment of the disclosure with a plurality of heat exchange means according to the second embodiment from FIG. 3.

[0034] FIG. 5 shows a schematic illustration of the heat exchange system according to one embodiment.

DETAILED DESCRIPTION

[0035] FIGS. 1 and 2 each illustrate a first embodiment of a heat exchange means 100 according to the disclosure, wherein FIG. 1 shows an isometric view and FIG. 2 shows a sectional illustration. The heat exchange means 100 is arranged directly on a fluid line 3, through which a heat transport fluid flows, and surrounds said fluid line. The heat exchange means 100 comprises two actuators 1, for example piezo actuators, an elastocaloric element 2 which is composed of elastocaloric material, and two fastening elements 4. The actuators 1, the elastocaloric element 2 and the fastening means 4 are each designed in the form of annular disks which are arranged around the fluid line 3 and surround the latter. The elastocaloric element 2 is surrounded in the longitudinal direction of the fluid line 3 by the two actuators 1, and in each case one end surface of the elastocaloric element 2 lies on one of the end surfaces of in each case one actuator 1. The respectively other end surface of each actuator 1 is connected in the longitudinal direction to an end surface of in each case one fastening element 4, and therefore the actuators 1 are held by the fastening elements 4 (end surfaces cannot be seen in this illustration). In the present embodiment, the fastening elements 4 are designed as a casing for the fluid line 3 and are placed around the latter. In a further embodiment which is not shown here, the fastening elements 4 are designed as cuffs which are placed around the fluid line 3 and are then tightened. The actuators 1 and the elastocaloric element 2 here can also have openings in their ring and/or an opening mechanism for their ring in order to be able to open them during the installation on the fluid line 3. The heat exchange means 100 is therefore fastened to the fluid line 3 by means of the fastening elements 4, and the actuators 1 are fixed on one side in each case.

[0036] FIG. 2 shows the internal design of the heat exchange means 100. Identical components are identified by the same reference signs and the description thereof again is dispensed with. A heat-conducting layer 5, for example made of copper, is provided between the elastocaloric element 2 and the fluid line 3, via which layer the elastocaloric element 2 is thermally connected to the fluid line 3. By means of the heat-conducting layer 5, firstly the contact surface on the fluid line 3 is increased, in the example illustrated in FIG. 2 approximately to the size of the elastocaloric element 2 and of the two actuators 1 together, and also the contact surface on the elastocaloric element 2 is increased, in which contact surface the heat-conducting layer 5 approximately completely surrounds the elastocaloric element. Secondly, the heat transport is increased by the material properties of the heat-conducting layer 5. Furthermore, a heat-insulating layer 6 is provided which is arranged around the actuators and which thermally insulates the actuators 1 from the heat-conducting layer 5 and from the fluid line 3. In addition, the heat-insulating layer 6 is arranged over the complete outer side of the heat exchange means 100the outer side is considered as being the outer circumferential surface of the components 1, 2, 4, i.e. the surface of said components 1, 2, 4 opposite the fluid line 3 and the end surfaces of the fastening elements 4 that are opposite the actuators 1and therefore prevents a heat loss in relation to the environment.

[0037] In order to activate the actuators 1, an electronic control unit 8 is provided which is connected to a current/voltage supply 9 and controls the electric current from the current/voltage supply 9 via the current line 7 toward the actuators 1. If the actuators 1 are supplied with current, they expand simultaneously. Since the two actuators 1 are fixed on one side each by the fastening element 4, the actuators can expand only in the direction of the elastocaloric element 2, as a result of which they each exert a force from both sides on the elastocaloric element 2, by means of which force the elastocaloric element 2 is compressed and deformed in the process. Owing to the elastocaloric effect, the deformation of the elastocaloric element 2 generates heat which is output via the heat-conducting layer 5 to the fluid line 3 in which the heat transport fluid flowing therein is heated. Depending on whether a consumer (not shown here) is intended to be heated or cooled, the heat is guided to the consumer or transported away until the heat is completely removed from the elastocaloric element 2. If the two actuators 1 are now no longer supplied with current, they retract into their starting state, and therefore force is no longer exerted on the elastocaloric element 2 and the latter likewise deforms back. During the deformation back, the elastocaloric element 2 absorbs heat which is removed via the heat-conducting layer 5 from the heat transport fluid now flowing through the fluid line 3, as a result of which the heat transport fluid cools. Depending on the application, the cooled heat transport fluid is now removed or supplied to the consumer. The heating or cooling power can be controlled via the introduced electrical energy (current/voltage) which is converted by the actuator 1 into mechanical energy. The transporting away of the heat transport fluid and the control thereof will be described in detail in conjunction with FIG. 5, in which the heat exchange system according to the disclosure is described.

[0038] FIG. 3 shows an isometric view of a second embodiment of the heat exchange means 110 with a plurality of actuators 1, a plurality of elastocaloric elements 2 and a plurality of fastening elements 4. Also in the case of the first embodiment, a plurality of actuators 1, a plurality of elastocaloric elements 2 and a plurality of fastening elements 4 can be provided by a plurality of heat exchange means 100 being arranged one behind another in the longitudinal direction of the fluid line 3. In contrast thereto, in the case of the second embodiment, two inner actuators 1i.e. the actuators which are not arranged first or last in the rowdivide a common fastening element 4. That is to say, one end side of the fastening element 4 is connected to the one actuator 1 and the other end side of the fastening element 4 is connected to the other actuator 1, and therefore the fastening element 4 in this case holds the two actuators 1 and fixes same. The heating or cooling power can be varied by the number of heat exchange means 100, 110 used and activated.

[0039] FIG. 4 shows part of a heat exchange system according to an embodiment of the disclosure in an isometric illustration. A plurality of heat exchange means 110 according to the second embodiment are arranged as a cascade on the common fluid line 3. The heat transport means 110 are arranged in rectilinear sections of the fluid line 3 in which the fluid line 3 has only a small curvature, if any at all. The plurality of heat transport means 110 are controlled via the electric line 7 by the common control unit 8 and are supplied by the common current/voltage supply 9. The actuators 1 are activated successively in terms of time, specifically in such a manner that the elastocaloric elements 2 always act on the same fluid volume of the heat transport fluid flowing through the fluid line 3. For this purpose, the actuators 1 are activated sequentially depending on the time which a fluid volume which has already absorbed or output heat requires in order to reach the next elastocaloric element 2. Said time can be calculated from flow properties, such as the flow speed, and the distance between the elastocaloric elements 2, or determined empirically. By means of this activation, the fluid volume which has already absorbed or output heat is further heated or cooled by the next elastocaloric element 2. As a result, the fluid volume is heated or cooled ever further from element to element.

[0040] FIG. 5 shows a schematic illustration of the entire heat exchange system according to one embodiment of the disclosure. The plurality of heat exchange means 110 and the fluid line 3, and also the electronic control unit 8, the current/voltage supply 9 and the electric line 7 correspond to those which are shown in FIG. 4 and to the description of which reference is made. In addition to the components which have already been described, this figure illustrates a reservoir 11, in which the heat transport fluid is stored, the consumer 17 and a feed pump 18 and also further lines 12, 13, 14, 15, 16, 19, return feed pumps 20 and valves 10, 21, which control the flow of the heat transport fluid. The valves 10 are arranged at the end of the fluid line 3 and the valves 21 at the beginning of the fluid line 3, the valves 10, 21 being designed as multi-way valves.

[0041] In order to provide a better description, it is assumed below that the consumer 17 is intended to be cooled. The heat transport fluid is conveyed out of the reservoir 11 by the feed pump 18 via the inflow line 19 to the fluid line 3. In the fluid line 3, the heat exchange means 110 act on the heat transport fluid in the manner already described in detail above. The heat transport fluid (volume) heated by the elastocaloric elements 2 is guided back directly to the reservoir 11 by a first outflow line 14 via the valves 10 without passing through the consumer. Accordingly, the first outflow line corresponds to a return line to the reservoir 11. Subsequently, the valves 10 are switched over and the heat transport fluid (volume) cooled subsequently by the elastocaloric elements 2 is conducted by a second outflow line 15 to the consumer 17 where it absorbs the heat from the consumer 17. In order to keep the heat loss low, the second outflow line 15 between the end of the fluid line 3 with the heat exchange means and the consumer 17 is kept as small as possible. The heat transport fluid is subsequently guided back via a further return line 16 to the reservoir 11. In the reservoir 11, the heated heat transport fluid and the heat transport fluid supplied to the consumer 17 are mixed.

[0042] In the event that the heat transport fluid is intended to be cooled further before it is conducted to the consumer 17 and to the reservoir 11, internal return lines 12, 13 are provided between the valves 10 and 21. Return feed pumps 20 are provided within the internal return lines 12, 13, said return feed pumps conveying the heat transport fluid back, after the latter has flowed through the fluid line 3 and been cooled by the elastocaloric elements 2, from the valves 10 at the end of the fluid line 3 to the valves 21 at the beginning of the fluid line 3 without said heat transport fluid flowing through the consumer 17 and/or the reservoir 11. The cooled heat transport fluid can now flow once again through the fluid line 3, where it is cooled again by the elastocaloric elements 2. In this exemplary embodiment, two internal return lines 12 and 13 are provided, wherein the cooled heat transport fluid flows via the one return line and the heated heat transport fluid via the other.

[0043] The same heat exchange system can also be used to heat the consumer. For this purpose, in the event of the activation described above, only the heated heat transport fluid has to be conducted to the consumer 17 where it outputs the heat to the consumer 17, and the cooled heat transport fluid is conducted directly to the reservoir 11.

[0044] In further exemplary embodiments which are not illustrated here, two consumers are provided which are each arranged in one of the two outflow lines 14, 15, wherein one of the two consumers is intended to be cooled and the other heated. Instead of conducting the heated heat transport fluid directly to the reservoir 11, said heat transport fluid flows through the other consumer to be heated and outputs its heat there before being conducted further to the reservoir 11. The cooled heat transport fluid furthermore flows through the consumer 17 to be cooled and is conducted to the reservoir 11.