POLYMER FILM HEAT EXCHANGER WITH INTEGRAL

MANIFOLDS

CLAIM OF PRIORITY

[0001] This application claims the benefit of U.S. Patent Application Serial No. 14/600,927, titled POLYMER FILM HEAT EXCHANGER WITH INTEGRAL FLUID DISTRIBUTION MANIFOLDS AND METHOD, filed on January 20, 2015, invented by Christopher Lee Martin and Grant Edward Dunham, the benefit of priority of which is claimed hereby, and which is incorporated by reference herein in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR

DEVELOPMENT

[0002] This invention was made with government support under Energy

Cooperative Agreement No. DE-AR0000309 awarded by the Advanced Research Projects Agency-Energy. The government has certain rights in the invention.

BACKGROUND

[0003] Polymer-based heat exchangers offer unique benefits to end users including low-cost material of construction, resistance to fouling due to smooth surfaces, and generally excellent corrosion resistance. However, polymers have relatively poor thermal conductivity, and it is not practical to construct a polymer heat exchanger based on conventional metal heat exchanger design principles. In order for the polymers to have sufficient mechanical strength for conventional metal heat exchanger designs, the wall thicknesses would be so thick as to hinder effective heat transfer.

[0004] Several designs have been proposed that adapt to the strength limitations of thin polymer interfaces, but none have resulted in a design simplicity that is required to dramatically lower costs. As a result, polymer-based heat exchangers are today limited to relatively high value applications that require the inertness that polymers can provide, e.g., pharmaceutical processing, healthcare products, and corrosive fluid processing.

[0005] US 4,411,310 and US 4,744,414 both refer to the use of polymer films to separate flow channels and serve as an effective heat exchanger surface. However, each of these examples also requires additional non-film components to complete the fluid circuits. US 4,411,310 refers to a separate molded manifold to which the polymer film flow channels are bonded in order to distribute the heat-transfer fluids to the appropriate flow channels. Similarly, US 4,744,414 refers to molded spacers between the polymer layers to form the flow channels and provide the fluid distribution function.

SUMMARY OF THE INVENTION

[0006] A polymer film heat exchanger wdth integral fluid distribution manifolds.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limi tation, various embodiments discussed in the present document.

[0008] FIG. 1 illustrates a perspective view of a heat exchanger assembly, in accordance with at least one example of the present subject matter.

[0009] FIG. 2 illustrates a top view ^? of a heat exchanger assembly, in accordance with at least one example of the present subject matter.

[0010] FIG. 3 illustrates a side view of a heat exchanger assembly, in accordance with at least one example of the present subject matter.

[0011] FIG. 4 illustrates a bonding pattern schematic of a film stack, in accordance with at least one example of the present subject matter.

[0012] FIG. 5 A illustrates cross section 5A-5A of the film stack of FIG.

4, in accordance with at least one example of the present subject matter. [0013] FIG. 5B illustrates cross section 5B-5B of the film stack of FIG.

4, in accordance with at least one example of the present subject matter.

[0014] FIG. 5C illustrates cross section 5C-5C of the film stack of FIG.

4, in accordance with at least one example of the present subject matter.

[0015] FIG. 6 illustrates a schematic drawing of cross section 5A-5A of

FIG. 4, in accordance with at least one example of the present subject matter.

[0016] FIG. 7 illustrates a schematic drawing of cross section 5B-5B of

FIG. 4, in accordance with at least one example of the present subject matter.

[0017] FIG. 8 illustrates a schematic drawing of cross section 5C-5C of FIG. 4, in accordance with at least one example of the present subject matter.

[0018] FIG. 9 illustrates a flow chart of a method, in accordance with at least one example of the present subject matter.

DETAILED DESCRIPTION

[0019] A heat exchanger operates to transfer heat from one fluid to another. The fluid can be liquid, vapor, or gas or a combination of the matter states. Hygroscopic fluids can be extremely useful in certain heat exchanger applications to limit water use. Hygroscopic fluids can be extremely corrosive and polymers can provide excellent resistance to corrosive fluids.

[0020] There is a need for a polymer heat exchanger that is low cost in construction and less complicated than previous heat exchangers. Described herein is a heat exchanger that includes a stack of film layers (film stack). The film stack can include alternating fluid passages that are separate from each other. Each fluid passage can include an input port and an output port and the input ports and output ports can be arranged so that the heat exchanger operates on a counter flow basis; fluid A flows in one direction and fluid B flows in the opposite direction.

[0021] The entire fluid circuit for both heat-transfer fluids, including the fluid distribution manifolds, can be formed using only a flexible polymer film. Forming integral manifolds out of the polymer film itself eliminates the need for additional pieces to be added to the heat exchanger.

[0022] The heat exchanger described herein formed from a stack of flexible polymer film sheets forms a parallel plate heat exchanger having alternating layers of fl ow channels. Fluid distribution can be accomplished by selectively bonding together film layers around flow channel apertures in an alternating manner so that a single fluid connection port can be only in fluid communication with alternating flow channels associated with only one of the heat exchange fluids. Dimensions of the flow channels can be regulated by regulating fluid pressures applied to one or more of the heat exchanger fluids. The entire assembly can be restrained from overexpansion by external rigid plates that sandwich the polymer film stack.

[0023] To further illustrate the heat exchanger and method disclosed herein, a non-limiting list of examples is provided here:

[0024] In Example 1, a device can comprise: a plurality of polymer films including a first film adjacent a second film and including a third film adjacent the second film, the plurality of polymer films in stacked alignment and having a stack axis normal to a plane of the plurality of polymer films, wherein the first film is bonded to the second film with a first bond having a first pattern configured to form a first channel between the first film and the second film, and further wherein the second film is bonded to the third film with a second bond having a second pattern configured to form a second channel between the second film and the third film, and further including a first pair of ports fluidly coupled to the first channel and including a second pair of ports fluidly coupled to the second channel, wherein the first pair of ports and the second pair of ports have port axes aligned substantially parallel with the stack axis.

[0025] In Example 2, the device of Example 1 can optionally be configured such that the third film is bonded to a fourth film with a third bond, the third bond having the first pattern and wherein the first channel is fluidly coupled to a region bound by the third film and the fourth film.

[0026] In Example 3, the device of Example 2 can optionally be configured such that the fourth film is bonded to a fifth film with a fourth bond, the fourth bond having the second pattern and wherein the second channel is fluidly coupled to a region bound by the fourth film and the fifth film.

[0027] In Example 4, the device of any one or any combination of

Examples 1-3 can optionally be configured such that the first channel is bound by the first bond and wherein the second channel is bound by the second bond. [0028] In Example 5, the device of any one or any combination of

Examples 1-4 can optionally be configured such that the first pair of ports and the second pair of ports are on a common side of the plurality of polymer films.

[0029] In Example 6, the device of any one or any combination of Examples 1-5 can optionally be configured such that the polymer films of the plurality of polymer films have a substantially rectangular profile and wherein the first pair of ports includes a first input port and includes a first output port and wherein the first input port and the first output port are aligned on a common diagonal determined by the profile.

[0030] In Example 7, the device of any one or any combination of

Examples 1-6 can optionally be configured such that at least one of the first bond and the second bond includes at least one of a thermal joint, a weld joint, and an adhesive joint.

[0031] In Example 8, the device of any one or any combination of Examples 1-7 can optionally be configured such that the first channel is fluidly isolated from the second channel.

[0032] In Example 9, the device of any one or any combination of

Examples 1-8 can optionally be configured to further include a first

reinforcement plate coupled to a first selected polymer film of the plurality of polymer films.

[0033] In Example 10, the device of Example 9 can optionally be configured to further include a second reinforcement plate coupled to a second selected polymer film of the plurality of polymer films.

[0034] In Example 11, the device of Example 10 can optionally be configured to further include at least one spacer coupled to the first

reinforcement plate and coupled to the second reinforcement plate, wherein the at least one spacer is configured to retain the first reinforcement plate and the second reinforcement plate in fixed alignment and at a predetermined distance apart.

[0035] In Example 12, the device of any one or any combination of

Examples 1-11 can optionally be configured such that the first film and the second film have a dimension in common. [0036] In Example 13, the device of any one or any combination of

Examples 1-12 can optionally be configured such that the first film, the second film, and the third film have an aperture in common.

[0037] In Example 14, a method can comprise forming a first bond coupling a first film and a second film, the first bond having a first bond pattern, the first film and the second film in stacked alignment and having a first channel therebetween; forming a second bond coupling the second film and a third film, the second bond having a second bond pattern, the second film and the third film in stacked alignment and having a second channel therebetween, the second channel fluidly independent of the first channel; forming a first pair of ports in the first film, the first pair of ports in fluid communication with the first channel; and forming a second pair of ports in the third film, the second pair of ports in fluid communication with the second channel.

[0038] In Example 15, the method of Example 14 can optionally be configured to further include forming a third bond coupling the third film and a fourth film, the third bond having the first bond pattern, the third film and the fourth film in stacked alignment and wherein the first channel is fluidly coupled to a region bound by the third film and the fourth film.

[0039] In Example 16, the method of Example 15 can optionally be configured to further include forming a fourth bond coupling the fourth film and a fifth film, the fourth bond having the second bond pattern, the fourth film and the fifth film in stacked alignment and wherein the second channel is fluidly coupled to a region bound by the fourth film and the fifth film.

[0040] In Example 17, the method of any one or any combination of Examples 14-16 can optionally be configured such that forming the first pair of ports and forming the second pair of ports includes forming on a common side of the films.

[0041] In Example 18, the method of any one or any combination of

Examples 14-17 can optionally be configured such that the first film, the second film, and the third film have a substantially rectangular profile and wherein forming the first pair of ports includes forming a first input port and includes forming a first output port and wherein the first input port and the first output port are aligned on a common diagonal determined by the profile. [0042] In Example 19, the method of any one or any combination of

Examples 14-18 can optionally be configured such that at least one of forming the first bond and forming the second bond includes forming at least one of a thermal joint, a weld joint, and an adhesive joint.

[0043] In Example 20, the method of any one or any combination of

Examples 14-19 can optionally be configured to further include affixing a first reinforcement plate to the first film.

[0044] In Example 21, the method of Example 20 can optionally be configured to further include affixing a second reinforcement plate coupled to a film.

[0045] In Example 22, the method of Example 21 can optionally be configured to further include providing at least one spacer coupled to the first reinforcement plate and coupled to the second reinforcement plate, wherein the at least one spacer is configured to retain the first reinforcement plate and the second reinforcement plate in fixed alignment and at a predetermined distance apart.

[0046] In Example 23, the device and method of any one or any combination of Examples 1-22 can optionally be configured such that all elements, operations, or other options recited are available to use or select from.

[0047] FIG. 1 illustrates a heat exchanger assembly 15. The heat exchanger assembly 15 can include a film stack 1 sandwiched between a first reinforcement plate 16 and a second reinforcement plate 18. The film stack 1 can be formed from a plurality of film layers 20 layered one atop the other. In this application, the term film layer 20 can refer to any of the film layers in the film stack 1. The film layers 20 can be formed of a polymer, rubber, plastic, metal or any combination or composite of materials that can contain a fluid. The film layers 20 can be flexible, semi-flexible or rigid. The film layers 20 can be in sheet form. The first and second reinforcement plates 16, 18 can be formed from a rigid material and can limit the expansion of the film stack. The first and second reinforcement plates 16, 18 can also provide a rigid structure that can be used for attachment. The first reinforcement plate 16 and the second reinforcement plate 18 can be separated by spacers 4. The heat exchanger assembly 15 and film stack 1 is illustrated as planar and rectangular. In an example, the heat exchanger assembly 15 and/or film stack 1 can be shaped as any regular or irregular polygon, circular, or as having both straight and curvilinear portions. In an example, the heat exchanger assembly 15 and/or film stack 1 can be all or partially non-planar, such as including arched, bowed, or curvilinear portions. The film stack 1 can include at least two separate fluid passages, such as a Fluid A flow passage 22 and a Fluid B flow passage 24. The fluid flow passages can be described as any portion of the heat exchanger to which a fluid has access. The Fluid A flow passage 22 can be associated with a Fluid A input port 5 and a Fluid A output port 6. The Fluid B flow passage 24 can be associated with a Fluid B input port 7 and a Fluid B output port 8. The ports can be described as the outer opening of the fluid passage. The ports can include fluid connections 30 that can be connected to the film stack 1 and extend through the first or second reinforcement plate 16, 18. The fluid connections 30 can be the fittings, tubings, piping, or fluid connectors that can connect to a continuation of the fluid passage or an additional fluid passage.

[0048] FIG. 2 illustrates a top view of a heat exchanger assembly 15, in accordance with at least one example of the present subject matter. The heat exchanger assembly 15, as illustrated, can be configured for two fluids. Fluid A and Fluid B. Each fluid can be liquid, vapor, or gas or a combination of the matter states. A heat exchanger assembly 15 can be used having more than two fluids. The heat exchanger assembly 15 can be configured for counterflow flow heat exchange, whereby Fluid A can enter Fluid A input port 5 and can exit Fluid A output port 6 and Fluid B can enter Fluid B input port 7 and can exit Fluid B output port 8. While this configuration is preferred for effective heat transfer, it is also recognized that a parallel flow configuration is also possible. The film stack 1 can include a substantially rectangular profile 34. The Fluid A input port 5 and the Fluid A output port 6 can be aligned on a first common diagonal 36 of the rectangular profile 34. The Fluid B input port 7 and the Fluid B output port 8 can be aligned on a second common diagonal 38 of the rectangular profile 34. The diagonal orientation shown encourages counterflow heat exchange between Fluids A and B. The input and output ports can be bonded to the film stack 1. (see FIGS. 5 A and 5C). In another example, the film stack 1 can be bonded and sealed to the first or second reinforcement plates 16, 18 and the fluid connections 30 (see FIG. 1) can be bonded and sealed to the first or second reinforcement plates 16, 1 8. [0049] The heat exchanger assembly 15 is illustrated as having the input and output ports extending through one reinforcement plate (see FIG. 1 ), but any configuration of porting can be used, such as having both input ports extending through one plate and both output ports extending through the opposite plate, or as having the ports of Fluid A extending through one plate and the ports of Fluid B extending through the opposite plate. The heat exchanger assembly 15 can be configured with one of the ports extending through one plate and the three other ports extending through the other plate.

[0050] An outer perimeter 41 of the film stack 1 is shown as located inwardly from the spacers 4. The spacers 4 can include a bore 13 and be positioned between corresponding holes 17 in the reinforcement plates 16, 18. A fastener 42 (such as a threaded bolt or threadless rivet) can extend through the bore 13 and holes 17 and secure the first reinforcement plate 16 to the second reinforcement plate 18. The spacers 4 and fasteners 42 can retain the reinforcement plates in fixed alignment and a predetermined distance apart. In another example, one or more spacers 4 can be integral with the first reinforcement plate 16, the second reinforcement plate 18, or both plates.

[0051] FIG. 3 illustrates a side view of a heat exchanger assembly 15, in accordance with at least one example of the present heat exchanger. The film stack 1 can be sandwiched between the first reinforcement plate 16 and the second reinforcement plate 18. The spacers 4 can provide a predetennined distance 44 that the film stack 1 can be allowed to expand when under fluid pressure. The reinforcement plates 16, 18 can prevent the film stack 1 from over- expanding. Although the film stack 1 is illustrated with approximately 12 film layers 20, any number of three or more film layers 20 can be used in the heat exchanger assembly 15.

[0052] FIG. 4 illustrates a bonding pattern schematic of a film stack 1 , in accordance with at least one example of the present subject matter. In the film stack 1, film layers 20 (see FIG. 3) can be stacked one upon the other to provide a desired thickness for the heat exchanger assembly 15. Each film layer 20 can be identical or very similar in size and shape and can include a Fluid A input aperture 46, a Fluid A output aperture 48, a Fluid B input aperture 50, and a Fluid B output aperture 52. The Fluid A input aperture 46 and the Fluid A output aperture 48 of each layer can be fluidly coupled to the Fluid A flow passage 22. The Fluid B input aperture 50 and the Fluid B output aperture 52 of each layer can be fluidly coupled to the Fluid B flow passage 24 (see FIG. 1).

[0053] FIG. 4 illustrates two bonding patterns, a first bonding pattern

10, and a second bonding pattern 9. One of the first bonding pattern 10 or the second bonding pattern 9 can be used on the first side of the film layer 20. The bonding pattern not used on the first side of the film layer 20 can be used on the opposite side of the film layer 20. In the first bonding pattern 10, a first pattern bond perimeter 40A can be bonded between layers. In the second bonding pattern 9 a second pattern bond perimeter 40B can be bonded between layers. Bonding includes at least one of a thermal j oint, a weld j oint or an adhesive j oint. The bonding forms a fluid tight seal that separates fluids from intermixing and prevents leakages. The first bonding pattern 10 includes bonding around the Fluid A input aperture 46 and the Fluid A output aperture 48, such that Fluid B in a flow channel does not intermix with Fluid A at the Fluid A input aperture 46 and the Fluid A output aperture 48. The second bonding pattern 9 includes bonding around the Fluid B input aperture 50 and the Fluid B output aperture 52, such that Fluid A in a flow channel does not intermix with Fluid B at the Fluid B input aperture 50 and the Fluid B output aperture 52.

[0054] FIG. 5A illustrates a cross section 5A-5A of the film stack 1 of FIG. 4, in accordance with at least one example of the present subject matter. The cross section 5A-5A can include the Fluid A input port 5 and the Fluid B output port 8. For description purposes, beginning from a first side 60 of the film stack 1, a first film 62 A can be bonded to a second film 62B by a first bond 66 A having a first bonding pattern 10 (see FIG. 4). The first bonding pattern 10 does not include any bonding between the first film 62A and the second film 62B in a region of the Fluid B output aperture 52 of the second film 62B. A first channel 70A can be formed between the first film 62A and the second film 62B. The first bond 66A can bond the Fluid A input aperture 46 of the second film 62B to the first film 62A so Fluid A and Fluid B cannot mix at the Fluid A input aperture 46. The first channel 70A can be fluidly connected to the Fluid B flow passage 24. In the example shown, the first film 62A has no fluid apertures and has no bonding on a bottom surface 72. In an example, the first film 62A could have fluid apertures that are bonded to the reinforcement plate. [0055] In an example, second film 62B is bonded on its bottom surface

56A with the first bond pattern 10 to the first film 62A. The second film 62B is bonded on its upper surface 57 with the second bond pattern 9 to the bottom surface 56B third film 62C. For example, when a film layer 20 is bonded to an adjacent film layer 20, one set of input/output apertures can have a fluid tight bond between the layers, while the other set of input output apertures can remain unbonded between the two layers. In conjunction with the first pattern bond perimeter 40A or the second pattern bond perimeter 40B , such bonding at the apertures can create a flow channel 58 for either Fluid A or Fluid B, depending on whether the first bonding pattern 10 or the second bonding pattern 9 is used between the two layers. When the bonding pattern around a fluid aperture is bonded, and two adjacent film layers are bonded together at the fluid aperture, then no fluid at that fluid aperture can get between those two film layers.

Conversely, when the bond pattern is such that two adjacent film layers are not bonded together at a fluid aperture, then fluid from the fluid aperture can enter between the two film layers and form a flow channel 58.

[0056] By alternating the first bonding pattern 10 and the second bonding pattern 9, the bonding patterns can be reversed, meaning that the first bonding pattern 10 can be bonded to a layer above, and the second bonding pattern 9 can be bonded to the layer below. This alternating pattern can be repeated until a desired number of flow channels 58 are reached. Each film layer 20 can be identical in dimensions and hole placements; the orientation of the bonding patterns can change from layer to layer, in other words the first bonding pattern 10 can be between one set of adjacent layers, the second bonding pattern 9 can be between the next set of adjacent layers and so on.

[0057] A third film 62C can be located over the second film 62B. The second film 62B can be bonded to the third film 62C by a second bond 66B having a second bonding pattern 9. The second bond 66B having the second bonding pattern 9 does not include any bonding between the second film 62B and the third film 62C in the region of the Fluid A input apertures 46 of the second and third films 62B, 62C. A second channel 70B can be formed between the second film 62B and the third film 62C. The second channel 70B can be fluidly connected to the Fluid A flow passage 22. The second bond 66B bonds the Fluid B output aperture 52 of the second film 62B to the Fluid B output aperture 52 of the third film 62C so Fluid A and Fluid B cannot mix at the Fluid B output aperture 52.

[0058] A fourth film 62D can be located over the third film 62C. A third bond 66C having the first bonding pattern 10 can bond the third film 62C to the fourth film 62D. The third bond 66C having the first bonding partem 10 does not include any bonding between the third film 62C and the fourth film 62D in the region of the Fluid B output aperture 52 of the third film 62C and the fourth film 62D. A third channel 70C can be formed between the third film 62C and the fourth film 62D. The third channel 70C can be fluidly connected to the Fluid B flow passage 24. The third bond 66C bonds the Fluid A input aperture 46 of the third film 62C to the fourth film 62D so Fluid A and Fluid B cannot mix at the Fluid A input aperture 46. There is a fluid passage 84 between the first pattern bond perimeter 40A of the third bond 66C and the Fluid A input aperture 46. This fluid passage 84 is a portion of the third channel 70C and can also be seen from the top view of FIG. 4. Such a fluid passage 84 can be found in all channels formed by the first bonding pattern 10.

[0059] A fifth film 62E can be located over the fourth film 62D. The fifth film 62E can be bonded to the fourth film 62D by a fourth bond 66D having the second bonding pattern 9. The fourth bond 66D having the second bonding pattern 9 does not include any bonding between the fourth film 62D and the fifth film 62E in the region of the Fluid A input aperture 46 of the fourth and fifth films 62D, 62E. A fourth channel 70D can be formed between the fourth film 62D and the fifth film 62E. The fourth channel 70D can be fluidly connected to the Fluid A flow passage 22. The fourth bond 66D bonds the Fluid B output aperture 52 of the fourth film 62D to the Fluid B output aperture 52 of the fifth film 62E so Fluid A and Fluid B cannot mix at the Fluid B output aperture 52.

[0060] The alternating bonding of the fi rst bonding pattern 10 and the second bonding pattern 9 to additional film layers 20 can also create a fifth channel 70E, a sixth channel 70F, a seventh channel 70G, an eighth channel 70H and a ninth channel 70J. The fifth, seventh and ninth channels 70E, 70G, 70J can be fluidly connected to the Fluid B flow passage 24. The sixth and eighth channels 70F, 70H can be fluidly connected to the Fluid A flow passage 22.

[0061] The film layers 20 of the film stack 1 can be stacked in a direction that is substantially normal to the plane of each film layer 20. The connection of the channels to a fluid flow passage, such as the connection of the first, third, fifth, seventh and ninth channels 70A, 70C, 70E, 70G, 70J to the Fluid B flow passage 24 can form a Fluid B port manifold 25 at both the Fluid B input port 7 (see also FIG. 5C) and the Fluid B output port 8. The Fluid B port manifold 25 can include a port axis 51 that is substantially perpendicular to the plane of the film stack 1. In a similar manner a Fluid A port manifold 23 can be formed at both the Fluid A input port 5 and the Fluid A output port 6 (see also FIG. 5C).

[0062] FIG. 5B illustrates a cross section 5B-5B of the film stack of FIG. 4, in accordance with at least one example of the present heat exchanger. Cross section 5B-5B is located near the middle of the film stack 1 and does not intersect any of the apertures 46, 48, 50, 52. The nine channels can be formed by alternating application of the first bonding pattern 10 and the second bonding pattern 9. The Fluid B flow passage 24 is fluidly coupled to the first channel 70A, the third channel 70C, the fifth channel 70E, the seventh channel 70G and the ninth channel 70J. The Fluid A flow passage 22 is fluidly coupled to the second channel 70B, the fourth channel 70D, the sixth channel 70F, and the eighth channel 70H (see FIG. 5A). As illustrated, there can be a great amount of surface area contact between channels flowing Fluid A and channels flowing Fluid B. The heat exchanger assembly 15 can be formed with as many or few flow channels as desired: simply by adding or subtracting film layers and changing the spacer 4 length and fastener 42 length if desired (see FIG. 3).

[0063] FIG. 5C illustrates a cross section 5C-5C of the film stack of

FIG. 4, in accordance with at least one example of the present subject matter. Cross section 5C-5C can include the Fluid B input port 7 and the Fluid A output port 6. Fluid connections 30 can be bonded to the outer surface 102 of a second side 104 of the film stack 1 at the flow passages 22, 24. The film layers 20 are bonded in the same manner as in FIG. 5A with alternating bonding patterns that form the first channel 70A, the third channel 70C, the fifth channel 70E, the seventh channel 70G and the ninth channel 70J fluidly coupled to the Fluid B flow passage 24. The Fluid A flow passage 22 is fluidly coupled to the second channel 70B, the fourth channel 70D, the sixth channel 70F, and the eighth channel 70H. FIG 4 and FIGS. 5A-C illustrate an example of the first bonding pattern 10 and the second bonding pattern 9. [0064] The film layer 20 can have a flattened sheet-like form. When containing a fluid, such as a pressurized fluid, the flow channels, such as channels 70A-H and 70J can expand the film layer 20 into a three dimensional form as shown. In an example, the film layer 20 can be formed of a semi-rigid material or pre-creased material that can maintain a three dimensional shape in a single layer or a non-pressurized channel. Additional bonds not needed for fluid channel sealing can be included between adjacent film layers to encourage uniform expansion of film layer 20 into a three dimensional form.

[0065] FIG. 6 illustrates an example of a schematic drawing of cross section 5A-5A of FIG. 4 (having fewer layers than FIG. 5 A) and includes a first reinforcement plate 16 and a second reinforcement plate 18. The bond segments of the first bond 66 A, the second bond 66B, the third bond 66C, and the fourth bond 66D (parts of continuous bond) that are shown directly across from each other represent a sealed bond between layers. A first film 62A can be directly adjacent a first reinforcement plate 16. The first film 62 A can be configured without flow passage apertures. The first film 62A can remain unbonded to the first reinforcement plate 16 or can be bonded to the first reinforcement plate 16. The cross section 5A-5A can include the Fluid A input port 5 and the Fluid B output port 8. Beginning from a first side 60 of the film stack 1, a first film 62A can be bonded to a second film 62B by a first bond 66A having a first bonding pattern 10. The first bonding pattern 10 does not include any bonding between the first film 62A and the second film 62B in the region of the Fluid B output aperture 52 of the second film 62B. A first channel 70A can be formed between the first film 62A and the second film 62B. The first bond 66A bonds the Fluid A input aperture 46 of the second film 62B to the first film 62A so Fluid A and Fluid B cannot mix at the Fluid A input aperture 46. The first channel 70A can be fluidly connected to the Fluid B flow passage 24. The circle depicted at the end of the lines showing the Fluid B flow passage 24 illustrates that it is not at a flow through point in the channel, such as in the first channel 70A where bonds 66A block the fluid from combining with the Fluid A flow passage 22. This pattern is repeated in FIG. 6 and FIG. 8 for the Fluid B flow passage 24 and the Fluid A flow passage 22.

[0066] A third film 62C can be located over the second film 62B. The second film 62B can be bonded to the third film 62C by a second bond 66B having a second bonding pattern 9. The second bond 66B having the second bonding pattern 9 does not include any bonding between the second film 62B and the third film 62C in the region of the Fluid A input aperture 46 of the second and third films 62B, 62C. A second channel 70B can be formed between the second film 62B and the third film 62C. The second channel 70B can be fluidly connected to the Fluid A flow passage 22. The second bond 66B bonds the Fluid B output aperture 52 of the second film 62B to the Fluid B output aperture 52 of the third film 62C so Fluid A and Fluid B cannot mix at the Fluid B output aperture 52.

[0067] A fourth film 62D can be located over the third film 62C. A third bond 66C having the first bonding pattern 10 can bond the third film 62C to the fourth film 62D. The third bond 66C having the first bonding pattern 10 does not include any bonding between the third film 62C and the fourth film 62D in the region of the Fluid B output aperture 52 of the third film 62C and the fourth film 62D. A third channel 70C can be formed between the third film 62C and the fourth film 62D. The third channel 70C can be fluidly connected to the Fluid B flow passage 24. The third bond 66C bonds the Fluid A input aperture 46 of the third film 62C to the fourth film 62D so Fluid A and Fluid B cannot mix at the Fluid A input aperture 46. The fluid passage 84 described previously is shown on channels having the first bonding pattern 10. In FIG. 6, fluid passage 84 is shown as a circle for illustrative purposes only. The circle represents a fluid passage 84 between the perimeter bond 40A and the bond at input aperture 46 (or output aperture 48 see FIG. 4), but this shape can be hexagonal as shown in FIG. 5A, oval shaped, or another shape determined by materials, bonding, fluid pressures or combinations thereof.

[0068] A fifth film 62E can be located over the fourth film 62D. The fifth film 62E can be bonded to the fourth film 62D by a fourth bond 66D having the second bonding pattern 9. The fourth bond 66D having the second bonding pattern 9 does not include any bonding between the fourth film 62D and the fifth film 62E in the region of the Fluid A input aperture 46 of the fourth and fifth films 62D, 62E. A fourth channel 70D can be formed between the fourth film 62D and the fifth film 62E. The fourth channel 70D can be fluidly connected to the Fluid A flow passage 22. The fourth bond 66D bonds the Fluid B output aperture 52 of the fourth film 62D to the Fluid B output aperture 52 of the fifth film 62E so Fluid A and Fluid B cannot mix at the Fluid B output aperture 52.

[0069] The alternating of the first bonding pattern 10 and the second bonding pattern 9 can also create a fifth channel 70E which can be fluidly connected to the Fluid B flow passage 24. Fluid connections 30 are shown bonded to the outer surface 102 of a sixth film 62F. The fluid connections 30 can extend through the second reinforcement plate 18. The fluid connections 30 can form fluid connections using any device common to the industry. These connections can include welded flanges or mechanical bulkhead fittings.

[0070] FIG. 7 illustrates bonds in a schematic drawing of cross section

5B-5B of FIG. 4 (but having fewer film layers than FIG. 5B), in accordance with at least one example of the present subject matter. The film stack 1 can be sandwiched between the first reinforcement plate 16 and the second

reinforcement plate 18. The five channels can be formed by alternating of the first bonding pattern 10 and the second bonding pattern 9. The Fluid B flow passage 24 can be fluidly coupled to the first channel 70A, the third channel 70C, and the fifth channel 70E. The Fluid A flow passage 22 can be fluidly coupled to the second channel 70B and the fourth channel 70D.

[0071] FIG. 8 illustrates bonds in a schematic drawing of cross section 5C-5C of FIG. 4 (but having fewer film layers than FIG. 5C), in accordance with at least one example of the present subject matter. Cross section 5C-5C can include the Fluid B input port 7 and the Fluid A output port 6. The film layers 20 are bonded in the same manner as in FIG. 6 with alternating bonding patterns that form the first channel 70A, the third channel 70C, and the fifth channel 70E fluidly coupled to the Fluid B flow passage 24. The Fluid A flow passage 22 is fluidly coupled to the second channel 70B and the fourth channel 70D.

[0072] Although the film stacks 1 in FIGS. 5 A-C and FIGS. 6-8 are illustrated as having the first, third, fifth, etc. channels coupled to the Fluid B flow passage 24, in an example the first film and second film can be bonded with the second bonding pattern 9 instead of the first bonding pattern 10. If the patterns are alternated as described above, the Fluid B flow passage would then be coupled with the even numbered channels and the Fluid A flow passage would be coupled to the odd numbered channels (e.g. first channel, third channel, fifth channel etc.). [0073] FIG. 9 illustrates a flow chart describing a method, in accordance with at least one example of the present heat exchanger. Method 900 includes at 910, bonding a first film and a second film. The first film and second film can be bonded by a first bond. The second film can be located over the first film in stacked alignment. The stacking can be substantially normal to a plane of the films. The first bond can include a first bond pattern. The first bond pattern can include bonding around a perimeter of the films and also bonding around one pair of fluid apertures. One pair of fluid apertures, an input port and an output port are not bonded and the first film and second film can have a first channel between them.

[0074] Method 900 includes at 920, bonding a second film and a third film. The third film can be located over the second film in stacked alignment. The second film and the third film can be bonded by a second bond. The second bond can include a second bonding pattern. The second bonding pattern can bond a perimeter between the second and third films. The second bond can form bonds around the respective pair of port apertures that are not bonded in the first bond and leave unbonded the respective pair of apertures that were bonded in the first bond. Such bonding can form a second channel between the second and third films. The second channel can be fluidly independent of the first channel. Although method 900 describes the first bond as having the first pattern, in another example, the first bond can have the second pattern. The first and second patterns are alternated, so if the first bond is the second pattern, the second bond will be the first pattern and so on.

[0075] Method 900 includes at 930, forming a first pair of ports. The first pair of ports can be in fluid communication with the first channel. Method 900 includes at 940 forming a second pair of ports. The second pair of ports can be in fluid communication with the second channel.

[0076] Method 900 can also include at 950, bonding a third film and a fourth film. The fourth film can be located over the third film in stacked alignment. The third film and the fourth film can be bonded by a third bond, having the first bonding pattern. The region bound by the third and fourth films can be fluidly coupled to the first channel. Method 900 can also include at 960, bonding a fourth film and a fifth film. The fifth film can be located over the fourth film in stacked alignment. The fourth film and the fifth film can be bonded by a fourth bond, having the second bonding pattern. The region bound by the fourth and fifth films can be fluidly coupled to the second channel.

[0077] Method 900 can also include at 970, forming both pairs of ports on a common side of the films. In an example, one pair of ports can be formed on one side of the films, while another pair of ports can be formed on the opposite side of the films. In an example, an input port for Fluid A and an input port for Fluid B can be formed on one side of the films, while an output port for Fluid A and an output port for Fluid B can be formed on the opposite side of the films. In an example, one port can be formed on one side of the films and three ports can be formed on the opposite side of the films. The additive sequence of 950 and 960 can be repeated for additional film layers to form the desired number of parallel flow channels.

[0078] Method 900 can also include at 975, films having a rectangular profile and having a pair of ports aligned on a common diagonal. The first film, the second film and the third film can have a substantially rectangular profile. Forming the first pair of ports can include forming a first input port and a first output port. The first input port and the first output port can be aligned on a common diagonal of the substantially rectangular profile. This diagonal port configuration encourages the counterflow interaction of Fluids A and B in during counterflow heat exchange.

[0079] Method 900 can also include at 980, bonding that includes at least one of a thermal joint, a weld joint or an adhesive joint. The bonding forms a fluid tight seal that separates fluids from intermixing and prevents leakages.

[0080] Method 900 can also include at 985, affixing a first

reinforcement plate to a film. The reinforcement plate can be a rigid material made of polymer, rubber, plastic, metal, or combinations thereof. Method 900 can also include at 990, affixing a second reinforcement plate to a film. The first and second reinforcement plates can sandwich the film layers between them. The reinforcement plates can prevent the layers of films from over-expanding from pressurized fluids, provide structural protection for the films, and provide a rigid structure for attachment to another structure. Method 900 can also include at 995, providing at least one spacer coupled to the reinforcement plates that can retain the plates in fixed alignment and at a predetermined distance apart. The spacer length can be adjusted to change the number of film layers or the expandable dimensions of channels between films.

[0081] The films used in method 900 can be flexible. In an example, the films can be formed of a semi-rigid material or pre-creased material that can maintain a three dimensional shape in a single layer or a non-pressurized channel. Additional bonds not needed for fluid channel sealing can be included patterns between adjacent film layers to encourage uniform expansion of film layers into a three dimensional form.

[0082] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments of the heat exchanger. These embodiments are also referred to herein as "examples." Such examples can include elements in addition to those shown or described.

[0083] The description herein is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.