Electric Heat Transfer Modular Stacking

Abstract

A heat transfer system is disclosed, comprising a plurality of modules arranged in a stack. The stacked module comprises an electric heating element and an electrode located on each side of a membrane. A fluid flow path is arranged between two or more electric heating elements. A first electric bus element (18) in electrical contact with a first electrode (14) and a second electric bus element (20) in electrical contact with a second electrode (16). The first electric bus element is electrically connected to at least one other electric bus of another electric heating element in the stack that is at the same polarity as the first electric bus, or the second electric bus element is electrically connected to at least one other electric bus of another electric heating element in the stack that is at the same polarity as the second electric bus.

Description

Background Art

[0001] There are a variety of technologies for cooling applications, including but not limited to evaporative cooling, convection cooling, or solid-state cooling such as electrothermal cooling. One of the most common technologies for residential and commercial refrigeration and air conditioning is a vapor compression refrigerant heat transfer loop. These loops usually circulate a refrigerant with appropriate thermodynamic properties through a loop including a compressor, a heat rejection heat exchanger (i.e., a heat exchanger condenser), an expansion device, and a heat absorption heat exchanger (i.e., a heat exchanger evaporator). The vapor compression refrigerant loop effectively provides cooling and refrigeration in various settings, and in some cases can be reversed as a heat pump. However, many refrigerants may have environmental hazards such as ozone depletion potential (ODP) or global warming potential (GWP), or may be toxic or flammable. In addition, in an environment lacking a readily available power source sufficient to drive a mechanical compressor in the refrigerant loop, a vapor compression refrigerant loop may be impractical or disadvantageous. For example, in an electric vehicle, the power demand of the air conditioning compressor may result in a significant reduction in vehicle battery life or driving range. Similarly, the weight and power requirements of the compressor may also become a problem in various portable cooling applications.

[0002] Therefore, there has been interest in developing cooling technologies as alternatives to vapor compression refrigerant loops. Various technologies such as field activated thermal or current responsive heat transfer systems that rely on materials such as electrocaloric, magnetocaloric, or thermoelectric materials have been proposed. However, many of the proposals have been configured as small-scale demonstrations with limited scalability or mass production capabilities. Summary of the invention

[0003] In some embodiments of the present disclosure, the heat transfer system includes a plurality of modules arranged in a stack. The stack module includes an electric heating element including an electric heating film. A first electrode is arranged on a first side of the electric heating film, and a second electrode is arranged on a second side of the electric heating film. A fluid flow path is arranged between two or more electric heating elements. A first electric bus element electrically in contact with the first electrode and a second electric bus element electrically in contact with the second electrode. The first electric bus element is electrically connected to at least one other electric bus of another electric heating element in the stack that is in the same polarity as the first electric bus, or the second electric bus element is electrically connected to at least one other electric bus of another electric heating element in the stack that is in the same polarity as the second electric bus.

[0004] The first electrical bus element is electrically connected to at least one other electrical bus of another electrical heating element in the stack at the same polarity as the first electrical bus, and the second electrical bus element is electrically connected to at least one other electrical bus of another electrical heating element in the stack at the same polarity as the second electrical bus.

[0005] In any of the foregoing embodiments, the first electrical bus or the second electrical bus is electrically connected to an electrical bus of an adjacent electrical heating element in the stack that is of the same polarity as the first electrical bus or the second electrical bus.

[0006] In any of the foregoing embodiments, the first and second electrical bus elements are each electrically connected to an electrical bus element of an adjacent electrical heating element in the stack that is of the same polarity as the first and second electrical bus elements, respectively.

[0007] In any of the foregoing embodiments, the first electrical bus element or the second electrical bus element is in an interlocking configuration with the electrical bus of an adjacent electrical heating element in the stack.

[0008] In any of the foregoing embodiments, the first electrical bus element and the second electrical bus element are each in an interlocking configuration with an electrical bus element of an adjacent electrical heating element in the stack.

[0009] In any of the foregoing embodiments, the first electrical bus element is electrically connected to a live electrode and the second electrical bus element is electrically connected to a ground electrode.

[0010] In any of the preceding embodiments, the first electrical bus element and the second electrical bus element are disposed along opposing edges of the electrical heating element.

[0011] In any of the foregoing embodiments, the first electrode extends from the first electrical bus element to a location physically separated from the second electrical bus element along the first side of the electrothermal film, and the second electrode extends from the second electrical bus element to a location physically separated from the first electrical bus element along the second side of the electrothermal film.

[0012] In any of the preceding embodiments, the first electrical bus element and the second electrical bus element are disposed along a common edge of the electrical heating element.

[0013] In any of the foregoing embodiments, at least two adjacent electric heating elements of a common electrode are at least partially embedded between the electric heating films of the adjacent electric heating elements.

[0014] In any of the foregoing embodiments, the embedded electrode is the live electrode and the electrode exposed to the fluid flow path is the ground electrode.

[0015] In any of the preceding embodiments, one or more spacer elements are disposed between the electric heating elements.

[0016] In any of the preceding embodiments, the one or more spacer elements extend axially along a direction of fluid flow along the fluid flow path.

[0017] In any of the preceding embodiments, the one or more axially extending spacer elements extend linearly along a direction of fluid flow along the fluid flow path.

[0018] In any of the preceding embodiments, the one or more axially extending spacer elements extend non-linearly along a direction of fluid flow along the fluid flow path.

[0019] In any of the preceding embodiments, the one or more spacer elements are not electrically conductive.

[0020] In any of the foregoing embodiments, the electric heating element has a thickness of 1 μm to 1000 μm.

[0021] In any of the preceding embodiments, the physical separation between the electric heating elements in adjacent modules is from 1 μm to 200 mm.

[0022] In any of the preceding embodiments, the plurality of modules further include a non-conductive support member connected to the electric heating element.

[0023] In any of the preceding embodiments, the support includes a headspace at an opposite end of the electric heating element that is in fluid communication with the fluid flow path.

[0024] In any of the preceding embodiments, the supports of the plurality of modules together form a housing within which the electric heating elements and the spacing elements are disposed.

[0025] In any of the preceding embodiments, the electrothermal film comprises an electrothermal polymer.

[0026] In any of the foregoing embodiments, the electrocaloric polymer comprises polyvinylidene fluoride (PVDF) or a liquid crystal polymer (LCP).

[0027] In any of the foregoing embodiments, the electric heating film includes an inorganic electric heating material.

[0028] In any of the preceding embodiments, the first electrode and the second electrode each include a metallization layer deposited on the electrothermal film.

[0029] In some embodiments, a heat transfer system includes an electric heating element formed by the method of any of the above embodiments; a first heat flow path between the electric heating element and the heat sink; a second heat flow path between the electric heating element and the heat source; and a controller configured to control the current to the conductive layer and selectively guide thermal energy from the electric heating element to the heat sink along the first heat flow path, or from the heat source to the electric heating element along the second heat flow path.

[0030] In another aspect, a method of making the heat transfer system of any preceding embodiment includes assembling repeating units of modules in a stacked configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the claims appended hereto. The foregoing and other features and advantages of the present disclosure will become apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0032] Figure 1 is a schematic diagram of a top view of an exemplary embodiment of an electrothermal heat transfer module;

[0033] Figure 2 is a schematic diagram of a cross-sectional side view of an exemplary embodiment of an electrothermal heat transfer module;

[0034] Figure 3A is a schematic diagram of an exploded perspective view of an electrode and electric heating film configuration;

[0035] Figure 3B yes Figure 4 A top view of a portion of an arrangement having an electrical bus element;

[0036] Figure 4 is a schematic diagram of an exemplary embodiment of a stacked assembly of a plurality of electrothermal heat transfer modules;

[0037] Figure 5 is a schematic diagram of an alternative exemplary embodiment of a stacked assembly of a plurality of electrothermal heat transfer modules; and

[0038] Figure 6 is a schematic diagram of an exemplary embodiment of a heat transfer system including an electric heat stack and other components. DETAILED DESCRIPTION

[0039] As described above, a heat transfer system is disclosed that includes a plurality of modules arranged in a stack. Figure 1 and Figure 2 An example of an embodiment of a module is schematically depicted in FIG. Although any directions described herein (e.g., "upper," "lower," "top," "bottom," "left," "right," "above," "below," etc.) are considered arbitrary and do not have any absolute meaning but only have meaning relative to other directions, Figure 1 A "top" view of an exemplary embodiment of what may be described as a module, and Figure 2 can be described as Figure 1 The line shown A "side" cross-section of the image. Figure 1 and Figure 2 As shown, the module 10 includes an electric heating element, which includes an electric heating film 12, a first electrode 14 on a first side of the film, and a second electrode 16 on a second side of the film. It is worth noting that for ease of description, in order not to obscure the details of the electric heating film 12 and other components, Figure 1 Electrodes 14 and 16 are omitted, and only Figure 2 It is shown in .

[0040] The electrothermal film 12 may include any of a number of electrothermal materials. In some embodiments, the electrothermal film thickness may be within a range having a lower limit of 0.1 μm, more specifically 0.5 μm, and even more specifically 1 μm. In some embodiments, the film thickness range may have an upper limit of 1000 μm, more specifically 100 μm, and even more specifically 10 μm. It should be understood that these range upper and lower limits may be independently combined to disclose many different possible ranges. Examples of electrothermal materials for electrothermal films may include, but are not limited to, inorganic materials (e.g., ceramics), electrothermal polymers, and polymer / ceramic composites. Examples of inorganics include, but are not limited to, PbTiO 3 (“PT”), Pb(Mg 1 / 3 Nb 2 / 3 ) 3 (“PMN”), PMN-PT, LiTaO 3 , barium strontium titanate (BST), or PZT (lead, zirconium, titanium, oxygen). Examples of electrothermal polymers include, but are not limited to, ferroelectric polymers, liquid crystal polymers, and liquid crystal elastomers.

[0041] Ferroelectric polymers are crystalline polymers or polymers with high crystallinity, in which the crystalline arrangement of the polymer is linked into thin sheets and / or the spherulite structure can be changed by applying an electric field. This property can be provided by a polar structure integrated into the polymer backbone, or a polar structure attached to the polymer backbone with a fixed orientation relative to the backbone. Examples of ferroelectric polymers include polyvinylidene fluoride (PVDF), polytriethylene fluoride, odd-numbered nylons, copolymers containing repeating units derived from vinylidene fluoride, and copolymers containing repeating units derived from triethylene fluoride. Extensive research has been conducted on the ferroelectric and electrothermal properties of polyvinylidene fluoride and copolymers containing repeating units derived from vinylidene fluoride. Examples of copolymers containing vinylidene fluoride include copolymers with methyl methacrylate and copolymers with one or more halogenated comonomers, including but not limited to trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, trichloroethylene, vinylidene chloride, vinyl chloride, and other halogenated unsaturated monomers.

[0042] Liquid crystal polymers or polymer liquid crystals include polymer molecules containing mesogenic groups. Mesogenic molecular structures are well known and are generally described as rod-shaped or disc-shaped molecular structures having an electron density orientation that produces a dipole moment in response to an external source field such as an external electric field. Liquid crystal polymers generally contain a plurality of mesogenic groups connected by non-mesogenic molecular structures. The non-mesogenic connecting structures and their connection, arrangement and spacing in the polymer molecules together with the mesogenic structures are important in providing a fluid deformable response to an external source field. Generally, the connecting structures provide sufficiently low rigidity to cause molecular rearrangement by applying an external source field, and provide sufficiently high rigidity to provide the properties of the polymer when no external source field is applied.

[0043] In some exemplary embodiments, the liquid crystal polymer may have a rod-like mesogenic structure in the polymer backbone separated by non-mesogenic spacer groups, which have flexibility to allow the mesogenic groups to reorder in response to an external source field. Such polymers are also referred to as main chain liquid crystal polymers. In some exemplary embodiments, the liquid crystal polymer may have a rod-like mesogenic structure attached as a side group attached to the polymer backbone. Such polymers are also referred to as side chain liquid crystal polymers.

[0044] Continue to refer to Figure 1 and Figure 2 , first electrode 14 is electrically connected to first electrical bus element 18. Similarly, second electrode 16 is electrically connected to second electrical bus element 20. The electrodes can be any type of conductive material, including but not limited to metallized layers of conductive metals such as aluminum or copper, or other conductive materials such as carbon (e.g., carbon nanotubes, graphene, or other conductive carbon). Noble metals can also be used, but this is not necessary. Other conductive materials such as doped semiconductors, ceramics, polymers, or conductive polymers can also be used. In some embodiments, such as Figure 2 As shown, the opposite polarity electrical bus elements 18 and 20 are disposed on opposite edges of the electrothermal film 12, which in some embodiments can provide a physical separation that can reduce the risk of short circuits. Figure 2 As shown, electrodes 14 and 16 may extend from one edge of the membrane at a location in contact with an electrical bus element and extend across the membrane to a location on the other edge of the membrane 12 that is not in contact with an electrical bus element of opposite polarity. Figure 3A and Figure 3B As shown, electrical bus elements 18 and 20 may be disposed on the same side of the electrical heating element. Figure 3A is a schematic diagram of a perspective exploded view of an electrothermal film 12 having a top electrode 14 and a bottom electrode 16 . Figure 3A and Figure 3B The top and bottom electrodes in the embodiment have lead portions 14y and 16y for electrical connection to the electrical bus element 19. The connection between the electrodes 14, 16 and the bus element 19 is Figure 3B 1 is depicted in a top view, wherein only a portion of the electric heating film 12 and the bus element 19 are shown. Figure 3B As shown, the bus element has a first polarity portion 19a connected to lead portion 14y of top electrode 14 and a second polarity portion 19b connected to lead portion 16y of bottom electrode 16, and a non-conductive portion 19c electrically isolating portions 19a and 19b of different polarities.

[0045] One or more support elements 22 may optionally be included to support and hold the electric heating element. However, since it may also be provided by Figure 4 The bus elements shown provide support and retention, so separate support elements are not necessary. Figure 1 As shown, support element 22 may be configured to provide header spaces 24 and 26 for conveying working fluid to and from the electrothermal element along fluid flow path 25. Although not required in all design configurations, in some embodiments, the support element may be made of a non-conductive material.

[0046] Spacer elements 28 may optionally be included to help maintain separation from adjacent electric heating elements of a fluid flow path for a working fluid (e.g., a fluid such as air to be directly heated or cooled, or a heat transfer fluid such as a dielectric organic compound). Any configuration of spacer elements may be utilized, such as a set of discrete disk-shaped spacer elements. However, in some aspects, the spacer elements extend axially in a direction parallel to the direction of the fluid flow path 25. Such axial extension may be, for example, Figure 1 The embodiment of the present invention may be linear (i.e., in a straight line) as shown, or may be non-linear (e.g., in a zigzag or wavy form extending generally in the axial direction). In some embodiments, non-linearity can promote good fluid mixing, while extending generally in the axial direction can help avoid excessive back pressure on the flowing fluid.

[0047] Now go to Figure 4 , which uses Figure 1 and Figure 2 As with the same numbering in FIG. 1 , a plurality of modules 10 are shown assembled together into a stack 30. Figure 4 As can be seen in FIG. 1 , the spacer facilitates maintaining a physical separation between adjacent heating elements to provide a fluid flow path 25 between the spacer and the adjacent heating element. Although not required in all design configurations, in which the spacer element is arranged as shown in FIG. Figure 4In the design configuration shown adjacent to the electrodes of opposite polarity, the spacing element can be made of a non-conductive material. In some embodiments, the spacing between adjacent electric heating elements can be in a range starting from a lower limit of 1 μm, more specifically 10 μm, and even more specifically 50 μm. In some embodiments, the separation interval range can have an upper limit of 200 mm, more specifically 10 mm, and even more specifically 2 mm. It should be understood that these range upper and lower limits can be independently combined to disclose many different possible ranges.

[0048] In some embodiments, adjacent electrical bus elements 18, 20 may have Figure 4 As used herein, interlocking means that adjacent elements have complementary protrusion and recess profiles, wherein a protrusion of one bus element is adjacent to or protrudes into a complementary recess of an adjacent bus element. This arrangement can facilitate assembly and promote structural integrity and electrical continuity of assembled bus elements in a stack in some embodiments.

[0049] Figure 4 depicts a stack having alternating electrical heating elements and fluid flow channels; however, Figure 4 This is only an example of a stacking embodiment and is not intended to be limiting. Figure 5 An alternative embodiment is depicted in FIG. Figure 5 , shows a stack 30a in which bus element 18b is connected to bus bar 18a and bus element 20b is connected to bus bar 20a. Figure 5 As shown, the electrode 16a electrically connected to the bus element 20b is at least partially embedded between the electric heating films 12 of adjacent electric heating elements. In this embodiment, the electrode 16a serves as an electrode for two adjacent electric heating elements, or in other words, two adjacent electric heating elements share a single electrode. The electrode 14a of opposite polarity is arranged on the outside of the "sandwich" of the electric heating element and is not shared. This structure can provide technical benefits by protecting the embedded electrode 16a from potential short circuits. In some embodiments, the at least partially embedded electrode is a live electrode, and the electrode exposed to the fluid flow path 25 is a ground electrode. It should be noted that although Figure 5 A sandwich of two films surrounding an embedded electrode is depicted, but sandwiches of more than two films with embedded electrodes of alternating polarity are also envisioned.

[0050] about Figure 6 Exemplary embodiments of heat transfer systems and their operation are further described. Figure 6As shown, the heat transfer system 310 includes an electric heat stack 311 having one or more conductive fluids in thermal communication with a heat sink 317 via a first heat flow path 318 and in thermal communication with a heat source 320 via a second heat flow path 322. A controller 324 is configured to control current through a power source (not shown) to selectively activate the electric heating elements (not shown) in the stack 311. The controller 324 is also configured to open and close control valves 326 and 328 to selectively direct the conductive fluid to flow along the first heat flow path 318 and the second heat flow path 322.

[0051] In operation, the system 310 can be operated by applying an electric field as a voltage difference across the electric heating elements in the stack 311 by the controller 324 to cause entropy reduction and heat energy release through the electric heating elements. The controller 324 opens the control valve 326 to transfer at least a portion of the released heat energy to the heat sink 317 along the heat flow path 318. This heat transfer can occur after the temperature of the electric heating element rises to a threshold temperature. In some embodiments, once the temperature of the electric heating element increases to approximately equal the temperature of the heat sink 317, heat transfer to the heat sink 317 begins. After applying the electric field for a period of time to cause the desired heat energy to be released from the electric heating element and transferred to the heat sink 317, the electric field can be removed. Removing the electric field causes the entropy of the electric heating element to increase and the heat energy to decrease. This reduction in heat energy is manifested as the temperature of the electric heating element decreasing to a temperature below the temperature of the heat source 320. The controller 324 closes the control valve 326 to terminate the flow along the heat flow path 318, and opens the control device 328 to transfer heat energy from the heat source 320 to the cooler electric heating element.

[0052] In some embodiments, for example, in the case of using a heat transfer system to maintain the temperature in the air-conditioned space or the thermal target, an electric field can be applied to the electric heating element to increase its temperature until the temperature of the electric heating element reaches a first threshold. After the first temperature threshold, the controller 324 opens the control valve 326 to transfer heat from the electric heating element to the radiator 317 until the second temperature threshold is reached. The electric field can be continued to be applied for all or part of the time period between the first temperature threshold and the second temperature threshold, and then the electric field is removed to reduce the temperature of the electric heating element until the third temperature threshold is reached. The controller 324 then closes the control valve 326 to terminate the heat flow transfer along the heat flow path 318, and opens the control valve 328 to transfer heat from the heat source 320 to the electric heating element. The above steps can be optionally repeated until the target temperature of the air-conditioned space or the thermal target (which can be a heat source or a radiator) is reached.

[0053] Although the present disclosure has been described in detail in conjunction with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to these disclosed embodiments. On the contrary, the present disclosure may be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements that have not been previously described but are consistent with the spirit and scope of the present disclosure. In addition, although various embodiments of the present disclosure have been described, it should be understood that various aspects of the present disclosure may include only some of the described embodiments. Therefore, the present disclosure should not be considered to be limited to the foregoing description, but only to the scope of the appended claims.

Claims

1. A heat transfer system comprising a plurality of modules arranged in a stack, each of the modules comprising: An electric heating element comprising an electric heating film, a first electrode on a first side of the electric heating film, and a second electrode on a second side of the electric heating film; a fluid flow path between two or more electrical heating elements; a first electrical bus element in electrical contact with the first electrode; as well as a second electrical bus element in electrical contact with the second electrode; Wherein, the first electric bus element is electrically connected to at least one other electric bus of another electric heating element in the stack with the same polarity as the first electric bus, or the second electric bus element is electrically connected to at least one other electric bus of another electric heating element in the stack with the same polarity as the second electric bus, and at least two adjacent electric heating elements share an electrode that is at least partially embedded between the electric heating films of the adjacent electric heating elements.

2. The heat transfer system according to claim 1, wherein: The at least partially embedded electrode is the live electrode and the electrode exposed to the fluid flow path is the ground electrode.

3. The heat transfer system according to claim 1 or 2, wherein: The first electrical bus or the second electrical bus is electrically connected to an electrical bus of an adjacent electrical heating element in the stack that has the same polarity as the first electrical bus or the second electrical bus.

4. The heat transfer system according to claim 1 or 2, wherein: The first and second electrical bus elements are each electrically connected to an electrical bus element of an adjacent electrical heating element in the stack that is of the same polarity as the first and second electrical bus elements, respectively.

5. The heat transfer system according to claim 1 or 2, wherein: The first electrical bus element or the second electrical bus element is in an interlocking configuration with the electrical bus of an adjacent electrical heating element in the stack, wherein the interlocking configuration means that the adjacent elements have complementary protrusion profiles and recess profiles, and the protrusion of one bus element is adjacent to or protrudes into the complementary recess of the adjacent bus element.

6. The heat transfer system of claim 5, wherein: The first electrical bus element and the second electrical bus element are each in an interlocking configuration with an electrical bus element of an adjacent electrical heating element in the stack.

7. The heat transfer system according to claim 1 or 2, wherein: The first electrical bus element is electrically connected to the live electrode and the second electrical bus element is electrically connected to the ground electrode.

8. The heat transfer system according to claim 1 or 2, wherein: The first electrical bus element and the second electrical bus element are disposed along opposing edges of the electrical heating element.

9. The heat transfer system of claim 8, wherein: The first electrode extends from the first electric bus element to a position physically separated from the second electric bus element along the first side of the electric heating film, and the second electrode extends from the second electric bus element to a position physically separated from the first electric bus element along the second side of the electric heating film.

10. The heat transfer system according to claim 1 or 2, wherein: The first electrical bus element and the second electrical bus element are disposed along a common edge of the electrical heating element.

11. The heat transfer system of claim 1 or 2, further comprising one or more spacer elements between the electric heating elements.

12. The heat transfer system of claim 11, wherein: The one or more spacer elements extend axially along a direction of fluid flow along the fluid flow path.

13. The heat transfer system of claim 12, wherein: The one or more axially extending spacer elements extend linearly along a direction of fluid flow along the fluid flow path.

14. The heat transfer system of claim 12, wherein: The one or more axially extending spacer elements extend non-linearly along a direction of fluid flow along the fluid flow path.

15. The heat transfer system of claim 11, wherein: The one or more spacer elements are electrically non-conductive.

16. The heat transfer system according to claim 1 or 2, wherein: The thickness of the electric heating element is 1 μm to 1000 μm.

17. The heat transfer system of claim 9, wherein: The physical separation between the electric heating elements in adjacent modules is from 1 μm to 200 mm.

18. The heat transfer system of claim 11, wherein: The plurality of modules also include a non-conductive support member connected to the electric heating element.

19. The heat transfer system of claim 18, wherein: The support member includes a headspace at an opposite end of the electrical heating element that is in fluid communication with the fluid flow path.

20. The heat transfer system of claim 18 or 19, wherein: The support members of the plurality of modules together form a housing, and the electric heating elements and the spacing elements are disposed within the housing.

21. The heat transfer system of claim 1 or 2, wherein: The electrothermal film includes an electrothermal polymer.

22. The heat transfer system of claim 21, wherein: The electrothermal polymer includes polyvinylidene fluoride (PVDF) or liquid crystal polymer (LCP).

23. The heat transfer system of claim 1 or 2, wherein: The electric heating film includes an inorganic electric heating material.

24. The heat transfer system of claim 1 or 2, wherein: The first electrode and the second electrode each include a metallization layer deposited on the electrothermal film.

25. The heat transfer system of claim 1 or 2, further comprising: a first heat flow path between the fluid flow path and a heat sink; a second heat flow path between the fluid flow path and a heat source; as well as A controller configured to control the current to the electrode and selectively direct thermal energy along the first heat flow path from the fluid flow path in thermal communication with the electric heating element to the heat sink, or along the second heat flow path from a heat source to the fluid flow path in thermal communication with the electric heating element.

26. A method of manufacturing a heat transfer system according to any one of claims 1 to 25, comprising assembling repeating units of the module in a stacked configuration.

Images