Internal hydroforming method for manufacturing heat pipe wicks

Abstract

A forming assembly configured to form a wick is disclosed. The forming assembly includes an expandable tube and a forming shell assembly. The expandable tube is hydraulically expandable to an expanded shape. The wick mesh is configured to be wrapped around the expandable tube. The forming shell assembly includes a first forming shell having a first recess defined therein and a second forming shell having a second recess defined therein. The first recess and the second recess cooperate to define an outer diameter of the wick. The expandable tube and the wick mesh are positionable between the first recess and the second recess. The expandable tube and forming shell assembly are configured to deform the wick mesh and form the wick based on hydraulic expansion of the expandable tube to the expanded shape.

Description

[Background technology]

[0001] Government Contracts This invention was made with Government support under Contract DE-NE0008853 awarded by the U.S. Department of Energy. The Government has certain rights in this invention.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Utility Application No. 16 / 853,270, filed April 20, 2020, which is incorporated by reference in its entirety.

[0003] The present invention relates generally to heat pipes used in heat transfer systems, and more specifically to a wick within a heat pipe configured to transport the working fluid of the heat pipe from a condenser region to an evaporator region of the heat pipe.

[0004] A heat pipe is a hermetically sealed two-phase heat transfer component used to transfer heat from a primary side (evaporator section) to a secondary side (condenser section). FIG. 1 illustrates, as an example, a heat pipe 100 including the aforementioned evaporator section 102 and condenser section 106 with an adiabatic section 104 extending therebetween. The heat pipe 100 further includes a working fluid (e.g., water, liquid potassium, sodium, or an alkali metal) and a wick 108. During operation, the working fluid is configured to absorb heat and evaporate in the evaporator section 102. Saturated vapor carrying the latent heat of vaporization flows through the adiabatic section 104 toward the condenser section 106. In the condenser section 106, the vapor condenses into a liquid pool 110 and releases its latent heat. The condensed liquid is then returned to the evaporator section 102 through the wick 108 by capillary action. The aforementioned flow paths of the working fluid are illustrated by the dashed arrows in FIG. 1. The phase change process and two-phase flow circulation continues as long as the temperature gradient between the evaporator and condenser sections is maintained. Due to the extremely high heat transfer coefficients for boiling and condensation, heat pipes are very effective heat conductors.

[0005] In nuclear systems, heat pipes are utilized by placing the evaporator section of the heat pipe within the core containing the nuclear fuel and the condenser section near a heat exchanger. The nuclear fuel evaporates the working fluid and the heat exchanger absorbs the latent heat in the condenser section. Examples of heat pipes in nuclear applications are described in U.S. Pat. No. 5,684,848, U.S. Pat. No. 6,768,781, and U.S. Patent Application Publication No. 2016 / 0027536, all of which are incorporated by reference in their entirety.

[0006] Another exemplary use of heat pipes in nuclear systems is in microreactors, which are nuclear reactors that generate less than 10 MWe and can be deployed in remote applications. These microreactors are packaged in relatively small containers, operate without active personnel involvement, and can operate without refueling / replacement for longer periods of time than conventional nuclear power plants. One such microreactor is the eVinci microreactor system, designed by Westinghouse Electric Company. The eVinci system is a heat pipe-cooled nuclear reactor power system that utilizes heat pipes to act as passive heat removal devices to efficiently transfer thermal energy from the reactor core to a heat exchanger.

[0007] Heat pipes used in microreactors undergo extreme operating temperatures (over 850°C) and require an internal wick made from a material that can withstand these temperatures and is compatible with the working fluid. This wick can be constructed from wire mesh that is rolled and diffusion bonded together into a tubular structure. The wick tube allows the working fluid in the heat pipe to pass radially (e.g., after the latent heat is released and the working fluid is absorbed by the wick) and along its axis (transporting the working fluid back towards the evaporator section by capillary action) while remaining rigid.

[0008] The manufacture of wicks for insertion into heat pipes requires a very complex and detailed process. Very generally, wicks are manufactured by rolling a sheet of woven wick mesh material into the desired shape, compressing a material (e.g., a tube) onto the wick to force it to deform into the desired shape, diffusion bonding the mesh together in a vacuum oven while maintaining the wick in compression, and then removing the used material and holding the wick in compression during the diffusion bonding. An example of this method of wick forming method is described in U.S. Patent No. 3,964,902, entitled "METHOD OF FORMING A WICK FOR A HEAT PIPE," incorporated herein by reference.

[0009] As noted above, current methods of forming wicks require that the material used to hold the wick in compression must be removed after the diffusion bonding process. As an example, U.S. Patent No. 3,964,902 describes the use of copper inner and outer mandrels to compress the wick, and then after diffusion bonding, the inner and outer mandrels must be chemically removed by chemical etching techniques. However, exposing the wick to this chemical etching process introduces impurities into the wick, reducing the wick's ability to perform its intended function. Chemical etching techniques also result in increased time and expense associated with the production of the wick.

[0010] It is an object of the present disclosure to provide an assembly and method for molding a wick that not only eliminates the need to use chemicals to remove material from the wick after it has been molded, but also at a significantly lower cost and time than other publicly documented methods. Summary of the Invention

[0011] In various embodiments, a forming assembly configured to form a wick is disclosed. The forming assembly comprises an expandable tube and a forming shell assembly. The expandable tube is hydraulically expandable to an expanded shape. The wick mesh is configured to be wrapped around the expandable tube. The forming shell assembly comprises a first forming shell with a first recess defined therein and a second forming shell with a second recess defined therein. The first recess and the second recess cooperate to define an outer diameter of the wick. The expandable tube and the wick mesh are positionable between the first recess and the second recess. The expandable tube and forming shell assembly are configured to deform the wick mesh and form the wick based on the hydraulic expansion of the expandable tube to the expanded shape.

[0012] In various embodiments, a method of forming a wick with a molded shell assembly comprising an expandable tube is disclosed. The method includes disposing a wick mesh around the expandable tube, disposing the expandable tube and the wick mesh within a receiving area of ​​the molded shell assembly, coupling a first end flange to a first side of the molded shell assembly, and coupling a second end flange to a second side of the molded shell assembly. The first end flange includes a hydraulic opening defined therein. The hydraulic opening is in fluid communication with the expandable tube. The method further includes clamping the molded shell assembly to a clamping plate assembly and applying pressure to the expandable tube through the hydraulic opening with a pressure source to transition the expandable tube to an expanded shape and to press the wick mesh against an inner surface of the molded shell assembly.

[0013] In various embodiments, a molding assembly configured to mold a wick is disclosed. The molding assembly includes a wick assembly including a porous support tube with pores defined therein, and an expandable tube configurable between a contracted shape and an expanded shape. The expandable tube is disposed around the porous support tube. The wick mesh is configured to be wrapped around the expandable tube. The molding shell assembly further includes a molding shell assembly including a first molding shell with a first recess defined therein and a second molding shell with a second recess defined therein. The wick assembly is positionable between the first recess and the second recess. The molding shell assembly further includes a first end flange and a second end flange. The first end flange is connectable to the first molding shell and the second molding shell. The first end flange includes therein a first receiving area configured to receive a first O-ring, a first portion of the porous support tube, and a first portion of the expandable tube, and a hydraulic opening configured to fluidly communicate a pressure source to the expandable tube. A second end flange is connectable to the first molded shell and the second molded shell, the second end flange including a second receiving area configured to receive therein the second O-ring, the second portion of the porous support tube, and the second portion of the expandable tube. [Brief description of the drawings]

[0014] The various features of the embodiments described herein, together with their advantages, may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

[0015] [Figure 1] FIG. 1 shows a working fluid moving through a heat pipe.

[0016] [Diagram 2] FIG. 2 is a mold assembly according to at least one embodiment of the present disclosure.

[0017] [Diagram 3]FIG. 3 is an exploded view of the molding assembly of FIG. 2 according to at least one embodiment of the present disclosure.

[0018] [Figure 4] FIG. 4 is a close-up view of an end flange, fastener, and O-ring of the mold assembly of FIG. 3 according to at least one embodiment of the present disclosure.

[0019] [Diagram 5] FIG. 5 is an enlarged view of the expandable tube, support tube, and wick mesh of the molding assembly of FIG. 3, according to at least one embodiment of the present disclosure.

[0020] [Figure 6] FIG. 6 is a first end flange of the mold assembly of FIG. 2 according to at least one embodiment of the present disclosure.

[0021] [Figure 7] FIG. 7 is a cross-sectional view of the first end flange of FIG. 6 according to at least one embodiment of the present disclosure.

[0022] [Figure 8] FIG. 8 is a second end flange of the mold assembly of FIG. 2 according to at least one embodiment of the present disclosure.

[0023] [Figure 9] FIG. 9 is a cross-sectional view of the second end flange of FIG. 8 according to at least one embodiment of the present disclosure.

[0024] [Figure 10] FIG. 10 is a front view of the molding assembly of FIG. 2 according to at least one embodiment of the present disclosure.

[0025] [Figure 11] FIG. 11 is a cross-sectional view of the molding assembly of FIG. 10 according to at least one embodiment of the present disclosure.

[0026] [Figure 12] FIG. 12 is a detailed view of the expandable tube and support tube inserted into the receiving area of ​​the first flange, according to at least one embodiment of the present disclosure.

[0027] [Figure 13] FIG. 13 is a detailed view of the expandable tube and support tube inserted into the receiving area of ​​the second flange, according to at least one embodiment of the present disclosure.

[0028] [Figure 14] FIG. 14 is a method of molding a wick with a molded shell assembly with an expandable tube according to at least one embodiment of the present disclosure.

[0029] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set forth herein illustrate various embodiments of the present invention in one form and such exemplifications are not to be construed as limiting the scope of the present invention in any manner. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The applicant of the present application owns the following patent applications filed concurrently with this application, each of which is incorporated herein by reference in its entirety:

[0031] The patent application, entitled “INTERNAL HYDROFORMING METHOD FOR MANUFACTURING HEAT PIPE WICKS UTILIZING A HOLLOW MANDREL AND SHEATH,” lists John Lojek III et al. as inventors, and is attorney docket number WEC-2020-011 / 200611P.

[0032] Numerous specific details are described to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments described herein and illustrated in the accompanying drawings. Well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described herein. The reader will appreciate that the embodiments described and illustrated herein are non-limiting examples, and thus, it can be understood that the specific structural and functional details disclosed herein may be representative and exemplary. Variations and modifications thereto may be made without departing from the scope of the claims.

[0033] FIG. 2 illustrates a forming assembly 200 for forming a wick, according to at least one embodiment of the present disclosure. FIG. 3 illustrates an exploded view of the forming assembly 200. With particular reference to FIGS. 3 and 5, the forming assembly 200 includes a wick forming assembly 201. The wick forming assembly 201 can include an expandable or inflatable tube 202 that can transition between an unexpanded or contracted shape and a hydraulically expanded or inflated shape. A sheet or multiple layered sheets 204 of wick mesh are configured to be wrapped or wrapped around the expandable tube 202. By way of example, the expandable tube 202 can be made of any suitable material, such as polyurethane. The material of the expandable tube 202 is selected such that when the wick mesh 204 is formed into the wick, the expandable tube 202 does not substantially adhere, adhere, or leave substantially no trace material on the wick to an extent that would detract from the composition, structural integrity, and / or shape of the wick, as described in more detail below.

[0034] The wick forming assembly 201 may also include a support tube 206. The support tube 206 is configured to be disposed within the expandable tube 202 and provide initial structural support to the expandable tube 202 and the wick mesh sheet 204 wrapped around the expandable tube 202. The support tube 206 includes a plurality of holes, openings, or pores formed therein such that a pressurized pressure medium, e.g., water, air, or other suitable pressure medium, applied through the support tube 206 applies a force to the expandable tube 202 through the holes in the support tube 206, causing the expandable tube 202 to transition to an expanded shape. In other words, the pores in the support tube 206 fluidly communicate a hydraulic pressure source with the expandable tube 202. The support tube 206 thus improves the structural integrity of the expandable tube 202 and facilitates the placement of the work mesh 204 around the expandable tube 202 without compromising the flexibility required for its expansion function.

[0035] The examples provided in connection with Figures 2 and 3 are designed to utilize an expandable tube 202 and a support tube 206 to create a tubular wick. However, this is not intended to be limiting. Other wick designs are contemplated by this disclosure, for example wicks having cross sections in the shape of a pentagon, hexagon, heptagon, octagon, or any suitable polygon. In such embodiments, a geometrically suitable expandable housing and support housing may be utilized.

[0036] 5, the length of the sheet of wick mesh 204 is configured to be cut shorter than the length of the expandable tube 202 and support tube 206 such that an uncovered zone 208 is defined between the end of the sheet of wick mesh 204 and the ends of the expandable tube 202 and support tube 206. Alternative embodiments are envisioned in which the wick mesh 204 is not cut shorter such that the lengths of the expandable tube 202, support tube 206, and wick mesh 204 are the same, or at least substantially the same.

[0037] 2 and 3, the mold assembly 200 may further include a molded shell assembly 210. The molded shell assembly 210 includes a top or first molded shell 212 and a bottom or second molded shell 214. By way of example, each of the first and second molded shells 212, 214 may be made from any suitable solid material, such as stainless steel. In one embodiment, the molded shells 212, 214 may be made from the same material as the wick mesh 204 material. Each of the first and second molded shells 212, 214 includes a cavity or recess 213, 215 extending along its length and defined therein. The recesses 213, 215 of the molded shells 212, 214 are configured to be complementary such that when the first and second molded shells 212, 214 are in abutting contact, the recesses 213, 215 cooperate to define a receiving area 218 configured to receive the wick forming assembly 201 and the sheet of wick mesh 204, seen in Figures 12 and 13. The recesses 213, 215 are sized such that when in abutting contact to define the receiving area 218, a gap g is defined between the wick mesh 204 and each of the recesses 213, 215.

[0038] The recesses 213, 215 in the first and second forming shells 212, 214 are configured to provide a solid surface and boundary for maximum deformation for the sheet of wick mesh 204. The recesses 213, 215 are configured to act on the sheet of wick mesh 204 wrapped around the expandable tube 202 as the expandable tube 202 hydraulically expands to an expanded shape. The recesses 213, 215 are configured to define the outer diameter and final shape of the wick. In one embodiment, the recesses 213, 215 comprise a semicircular cross-sectional shape with a radius of curvature, as shown by way of example in FIG. 3, such that when the first and second forming shells 212, 214 are in abutting contact, the semicircular recesses 213, 215 form a circular shape over the entire length of the forming shell assembly 210. Other embodiments are envisioned in which the recesses 213, 215 in each molded shell 212, 214 include other complementary shapes such that when the first and second molded shells are in abutting contact, the recesses 213, 215 cooperate to form other shapes, such as an oval, a square, or any other symmetrical shape desired for the wick. Other examples are envisioned in which the recesses 213, 215 in each molded shell 212, 214 are dissimilar to the other such that when the first and second molded shells are in abutting contact, a wick of asymmetrical shape can be formed. The recesses 213, 215 can be shaped such that any desired wick shape is possible.

[0039] 3, the molded shell assembly 210 may further include a first end flange 220 and a second end flange 222. The first end flange 220 and the second end flange 222 are configured to be secured to the ends of the first molded shell 212 and the second molded shell 214 by a plurality of fasteners 224. In one embodiment, the fasteners 224 may comprise bolts configured to thread into threaded openings defined in the first and second molded shells 212, 214. Although the fasteners 224 are shown and described, other suitable methods for coupling the end flanges 220, 222 to the first and second molded shells 212, 214 are envisioned, such as, by way of example, using latching mechanisms, adhesives, or clamps.

[0040] As shown in FIGS. 8 and 12, the first end flange 220 includes a wick assembly receiving area 228, a groove 230 extending around the wick assembly receiving area 228, and a hydraulic opening 232. As described above, the length of the sheet of wick mesh 204 is configured to be cut shorter than the length of the expandable tube 202 and the support tube 206 such that an uncovered zone 208 is defined between an end of the sheet of wick mesh 204 and an end of the expandable tube 202 and the support tube 206. As shown in FIG. 12, a portion of the uncovered zone 208 is configured to be received by the wick assembly receiving area 228 of the first end flange 220. Additionally, an O-ring 234 is configured to be disposed within the groove 230 such that the O-ring 234 is disposed around a portion of the uncovered zone 208. The combination of the uncovered zone 208 and the O-ring 234 within the wick assembly receiving area 228 creates a seal within the molded shell assembly 210. 9 and 13, the second end flange 222 is substantially similar to the first end flange 220, except that the second end flange 222 does not include hydraulic openings 232. Alternative embodiments are envisioned in which both the first and second end flanges 220, 222 include hydraulic openings 232.

[0041] The hydraulic openings 232 in the first end flange 220 are configured to interface with a hydraulic source, such as a water source, an air source, or any other suitable hydraulic source, configured to apply pressure to the expandable tube 202 through the hydraulic openings 232 and the pores defined in the support tube 206, causing the expandable tube 202 to transition to an expanded configuration.

[0042] As described above, a portion of the uncovered zone 208 of the wick forming assembly 201 is configured to be inserted through the wick assembly receiving area 228 and the O-rings 234 of the first and second end flanges 220, 222 to create a seal. The seal allows for internal pressurization of the expandable tube 202 by a hydraulic pressure source. The seal also prevents fluid from leaking or leaking out of the forming shell assembly 210 and prevents hydraulic fluid from contacting the wick mesh 204 around the expandable tube 202. Additionally, as described above, the length of the sheet of wick mesh 204 is configured to be cut shorter than the length of the expandable tube 202 and the support tube 206 to prevent the wick mesh 204 from expanding into uneven surfaces of the first and second end flanges 220, 222, such as the wick assembly receiving area 228 or the grooves 230.

[0043] 2 and 3, the mold assembly 200 may include a clamp plate assembly 240. The clamp plate assembly 240 may include a first clamp plate 242 and a second clamp plate 244. The first clamp plate 242 is configured to abut the first mold shell 212, the first end flange 220, and the second end flange 222. The second clamp plate 244 is configured to abut the second mold shell 214, the first end flange 220, and the second end flange 222. Alternate embodiments are envisioned in which the clamp plates 242, 244 only contact the mold shells 212, 214 and not the end flanges 220, 222. A plurality of fasteners 246 may be configured to secure the first clamp plate 242 to the second clamp plate 242. The clamp plate assembly 240 may be sized to accommodate any number of mold shell assemblies.

[0044] The clamp plate assembly 240 is configured to apply a preload pressure to the forming shell assembly 210 such that when a pressure source hydraulically expands the expandable tube 202 and the wick mesh 204 into abutting contact with the recesses 213, 215 of the forming shells 212, 214, the forming shells 212, 214 remain compressed without separation therebetween. In one embodiment, the plurality of fasteners 246 may comprise bolts, nuts, and washers, as shown in FIG. 3. In lieu of the clamp plate assembly 240, other means for preventing the first and second forming shells 212, 214 from separating are contemplated by the present disclosure, such as a latch assembly, a plurality of clamps, or any other suitable means for preventing the first and second forming shells from separating during pressurization of the expandable tube 202.

[0045] The clamp plate assembly 240 is configured to provide additional structural rigidity to the forming shell assembly 210 and minimize deformation due to compression of the expandable tube 202. A number of fasteners 246 along the length of the clamp plate assembly 240 can be configured to center the forming shell assembly 210 within the clamp plate assembly 240. In one embodiment, the clamp plate assembly 240 can include a groove that serves as a centering mechanism for the forming shell assembly 210. The thickness and overall dimensions of the first and second clamp plates 242, 244 can be modified to accommodate the higher internal molding pressures experienced by the expandable tube 202.

[0046] In operation, a sheet or multiple layered sheets of wick mesh 204 are configured to be tightly rolled or wrapped around a wick forming assembly 201, which may be comprised of an expandable tube 202 and a support tube 206. The wick mesh layer 204 is purposely cut short so that uncovered zones 208 are defined at both ends of the wick forming assembly 201. The wick forming assembly 201 and the rolled wick mesh 204 are then placed within the receiving area 218 of the forming shell assembly 210. In other words, the wick forming assembly 201 and the rolled wick mesh 204 are placed within the first forming shell recess 213 of the first forming shell 212, and then the second forming shell 214 is placed over the first forming shell 212, and the wick forming assembly 201 and the rolled wick mesh 204 are covered by the second forming shell recess 215. As shown in FIGS. 12 and 13, the wick forming assembly 201 is axially positioned within the forming shell assembly 210 such that a portion of the uncovered zone 208 extends from each side of the forming shell assembly 210 .

[0047] Another embodiment is envisioned in which a sheet or multiple layered sheets of wick mesh 204 are placed into the receiving area 218 of the molded shell assembly 210, the expandable tube 202 and support tube 206 are then placed into the receiving area 218, and the wick mesh 204 is wrapped around the expandable tube and support tube 206. Another embodiment is also envisioned in which the wick mesh 204 is intentionally cut short to define uncovered zones 208 such that uneven ends of the wick are removed from the uniform areas of the wick after the wick is molded by the process described below.

[0048] Next, an O-ring 234 is placed in the groove 230 of each of the first end flange 220 and the second end flange 222, as shown by way of example in Figures 12 and 13. The first end flange 220 and the second end flange 222 are then each configured to receive the uncovered zone 208 of the wick mold assembly 201 in the respective wick assembly receiving area 228. The uncovered zone 208 is inserted through the wick assembly receiving area 228 and through the O-ring 234 of the respective end flanges 220, 222, as described above, to create a seal within each end flange 220, 222. The first and second end flanges 220, 222 then couple to the ends of the molded shell assembly 210 with fasteners 224.

[0049] The clamp plate assembly 240 may then be placed around the formed shell assembly 210, as shown in Figure 2. Fasteners 246 are utilized to secure the first clamp plate 242 to the second clamp plate 244, providing a preload pressure to the formed shell assembly 210.

[0050] After the clamp plate assembly 240 is placed around the molded shell assembly 210, a pressure source, e.g., a hydraulic source, can apply pressure to the inside of the expandable tube 202 through the hydraulic openings 232 in the first flange 220 and the pores defined in the support tube 206. The expandable tube 202 hydraulically expands to an expanded shape, forcing the wick mesh 204 outward toward the recesses 213, 215 in the first and second molded shells 212, 214. As it is forced outward, the wick mesh 204 unravels and tightly coils until it contacts the recesses 213, 215. Another pressure can then be applied such that localized plastic deformation occurs at the contact areas of the wick mesh 204, forming a mechanical interlock between the wick mesh layers. After a maximum molding pressure (up to 30 ksi, as an example) is applied and the layers of wick mesh form a molded annular wick, the expandable tube 202 is depressurized. The final outer diameter of the wick is determined by the recesses 213, 215 in the first and second molded shells 212, 214. The final thickness of the wick is determined by the thickness and the initial and spread lengths of the wick mesh.

[0051] When the expandable tube 202 is depressurized, the expandable tube 202 transitions to an unexpanded shape. As a result of the expandable tube 202 being fabricated from a material, e.g., polyurethane, the expandable tube 202 separates from the wick as it transitions to an unexpanded shape, allowing, by way of example, manual removal of the expandable tube 202 from the wick without the need for chemical treatment, e.g., chemical etching or chemical dissolution. The unique and novel forming assembly 200 differs from other forming methods that use drawn copper and chemical etching, such as described in U.S. Pat. No. 3,964,902, incorporated herein by reference above. As discussed above with respect to the alternative forming methods, the copper is mechanically deformed into a mesh material and cannot be manually removed without chemically removing the copper and damaging the rolled wick mesh.

[0052] The mold assembly 200 is designed with features that allow for easy and convenient assembly / disassembly. To disassemble the mold assembly after the wick has been molded and the mold assembly 200 has been depressurized, the mold shell assembly 210 can be pushed out from between the clamp plates 242, 244 by loosening or removing the fasteners 246 of the clamp plate assembly 240. The first and second end flanges 220, 222 are then removed by removing the associated fasteners 214. The design of the O-rings 234 allows the flanges 220, 222 to slide off the uncovered zones 208 at the ends of the expandable tube 202 and the support tube 206. As mentioned above, the wick mesh 204 remains deformed after the molding process, allowing the expandable tube 202 to transition to an unexpanded shape and separate from the wick. The space between the expandable tube 202 and the wick allows the expandable tube 202 and the support tube 206 to be easily removed. The top and bottom molded shells 212, 214 can then be separated and the wick removed.

[0053] The above mold assembly and associated process produces a wick that has been diffusion bonded and tested to prove that it has the suitable dimensions (outer diameter, thickness), tolerances (approximately ±0.001 inch diameter), pore size, and strength required for use in a heat pipe. The mold assembly and associated process have also proven to be highly repeatable through multiple trials.

[0054] In one embodiment, the forming assembly 200 can be configured to create a wick one foot long with a particular diameter and thickness (based on the predetermined dimensions of the recesses 213, 215 and the selected number of layers of the wick 214). In another embodiment, the forming assembly 200 can be configured to create wicks up to about five feet long with the same wick diameter and thickness dimensions. The design of the forming assembly 200 may be used to create successive assemblies to create various lengths (as detailed herein) or with slight modifications to the design, may be assembled for removal. Any formed wick length, diameter, and thickness is possible by utilizing the forming assembly described above and varying the dimensions of the recesses 213, 215, the length of the forming shell assembly 210, and the number of layers of the wick mesh 204.

[0055] The final outer diameter of the wick is determined by the recess in the molded shell, and as described above, the size and shape of the recess can be varied to create molded wicks of various sizes and shapes.

[0056] 14, a method 300 of forming a wick with a molded shell assembly 200 with an inflatable or hydraulically expandable tube is illustrated in accordance with at least one embodiment of the present disclosure. The method 300 includes disposing a wick mesh around the inflatable tube 302, disposing the inflatable tube and the wick mesh within a receiving area of ​​the molded shell assembly 304, coupling a first flange to a first side of the molded shell assembly 306, coupling a second flange to a second side of the molded shell assembly 308, clamping the molded shell assembly with a clamp plate assembly (310), and applying pressure to the inflatable tube through a hydraulic opening with a pressure source 312 to transition the expandable tube to an expanded shape and press the wick mesh against an inner surface of the molded shell assembly. The method 300 may also include, if desired, transitioning the expandable tube to a contracted shape and removing the wick from the expandable tube. Method 300 may optionally include removing the wick from the expandable tube, including removing the wick from the expandable tube without chemical treatment. Method 300 may optionally include disposing the expandable tube around a porous support tube. Methods may optionally include disposing a first O-ring, a first portion of the porous support tube, and a first portion of the expandable tube not covered by the wick mesh in a first receiving area defined by a first flange, and disposing a second O-ring, a second portion of the porous support tube, and a second portion of the expandable tube not covered by the wick mesh in a second receiving area defined by a second flange. EXAMPLES

[0057] Various aspects of the subject matter described herein are illustrated in the following examples.

[0058] Example 1 A forming assembly configured to form a wick, the forming assembly comprising an expandable tube and a forming shell assembly. The expandable tube is hydraulically expandable to an expanded shape. The wick mesh is configured to be wrapped around the expandable tube. The forming shell assembly comprises a first forming shell with a first recess defined therein and a second forming shell with a second recess defined therein. The first recess and the second recess cooperate to define an outer diameter of the formed wick. The expandable tube and the wick mesh are positionable between the first recess and the second recess. The expandable tube and forming shell assembly are configured to deform the wick mesh and form the wick based on the hydraulic expansion of the expandable tube to the expanded shape.

[0059] Example 2 The molding assembly of example 1, wherein the wick is configured to separate from the expandable tube based on the expandable tube transitioning to an unexpanded shape.

[0060] Example 3 The molded assembly of example 2, wherein the wick is configured to separate from the expandable tube without chemical treatment.

[0061] Example 4 - The molded assembly of any one of Examples 1-3, wherein the expandable tube comprises polyurethane.

[0062] Example 5 The mold assembly of any one of Examples 1-4, further comprising a clamp plate assembly configured to clamp the first mold shell to the second mold shell, the clamp plate assembly comprising a first clamp plate configured to abut the first mold shell, a second clamp plate configured to abut the second mold shell, and a fastener configured to secure the first clamp plate to the second clamp plate.

[0063] Example 6 The molding assembly of any one of Examples 1-5, further comprising a support tube positionable within the expandable tube, the support tube having a pore defined therein, the pore configured to fluidly connect a pressure source to the expandable tube.

[0064] Example 7 The mold assembly of any one of Examples 1-6, further comprising an end flange configured to couple the first mold shell to the second mold shell, the end flange having a hydraulic opening defined therein, and the expandable tube is configurable to hydraulically expand to an expanded shape based on pressure applied through the hydraulic opening by a pressure source.

[0065] Example 8 The molded assembly of example 7, wherein the end flange comprises a receiving area configured to receive therein a portion of the expandable tubing not covered by the O-ring and wick mesh.

[0066] Example 9 A method of forming a wick with a molded shell assembly comprising an expandable tube, the method including: disposing a wick mesh around the expandable tube; disposing the expandable tube and the wick mesh within a receiving area of ​​the molded shell assembly; coupling a first end flange to a first side of the molded shell assembly; and coupling a second end flange to a second side of the molded shell assembly. The first end flange includes a hydraulic opening defined therein. The hydraulic opening is in fluid communication with the expandable tube. The method further includes clamping the molded shell assembly with a clamping plate assembly and applying pressure to the expandable tube through the hydraulic opening with a pressure source to transition the expandable tube to an expanded shape and to press the wick mesh against an inner surface of the molded shell assembly.

[0067] Example 10 The method of example 9, wherein applying pressure to the expandable tube comprises applying pressure to the expandable tube, which causes the expandable tube to plastically deform the wick mesh and shape the wick.

[0068] Example 11 11. The method of example 10, further comprising transitioning the expandable tube to a contracted configuration and removing the wick from the expandable tube.

[0069] Example 12 The method of example 11, wherein removing the wick from the expandable tube comprises removing the wick from the expandable tube without chemical treatment.

[0070] Example 13 13. The method of any one of Examples 9-12, further comprising disposing an expandable tube around the porous support tube, wherein pores defined in the porous support tube are configured to fluidly couple a pressure source to the expandable tube.

[0071] Example 14 The method of example 13, further comprising placing the first O-ring, the first portion of the porous support tube, and the first portion of the expandable tubing not covered by the wick mesh in a first receiving area defined by the first end flange, and placing the second O-ring, the second portion of the porous support tube, and the second portion of the expandable tubing not covered by the wick mesh in a second receiving area defined by the second end flange.

[0072] Example 15 A molding assembly configured to mold a wick, the molding assembly comprising a porous support tube with pores defined therein and an expandable tube configurable between a contracted shape and an expanded shape. The expandable tube is disposed around the porous support tube. The wick mesh is configured to be wrapped around the expandable tube. The molding assembly further comprises a molding shell assembly comprising a first molding shell with a first recess defined therein and a second molding shell with a second recess defined therein. The wick assembly is positionable between the first recess and the second recess. The molding shell assembly further comprises a first end flange and a second end flange. The first end flange is connectable to the first molding shell and the second molding shell. The first end flange comprises a first receiving area configured to receive therein a first O-ring, a first portion of the porous support tube, and a first portion of the expandable tube, and a hydraulic opening configured to fluidly communicate a pressure source to the expandable tube. The second end flange is connectable to the first molding shell and the second molding shell. The second end flange includes a second receiving area configured to receive therein the second O-ring, the second portion of the porous support tube, and the second portion of the expandable tube.

[0073] Example 16 The mold assembly of example 15, further comprising a means for preventing the first molded shell and the second molded shell from separating as the expandable tube expands to the expanded shape.

[0074] Example 17 17. The molded assembly of any one of Examples 15 or 16, wherein the expandable tube comprises polyurethane.

[0075] Example 18 The mold assembly of any one of Examples 15-17, wherein the first recess and the second recess are configured to define an outer diameter of the wick.

[0076] Example 19 A molding assembly described in any one of Examples 15 to 18, wherein the expandable tube is configured to deform the wick mesh and shape the wick based on the expandable tube transitioning to an expanded shape.

[0077] Example 20 The molded assembly of Example 19, wherein the wick is configured to separate from the expandable tube without chemical treatment.

[0078] Unless otherwise specifically stated as is apparent from the above disclosure, discussions throughout the above disclosure using terms such as "processing," "computing," "calculating," "determining," "displaying," and the like refer to the acts and processes of a computer system or similar electronic computing device that manipulates and transforms data represented as physical (electronic) quantities in the computer system's registers and memory into other data that is similarly represented as physical quantities in the computer system's memory or registers, or other such information storage, transmission, or display device.

[0079] One or more components may be referred to herein as being "configured to," "configurable to," "operable to," "adapted to," "capable to," "adaptable to," etc. Those skilled in the art will recognize that unless the context requires otherwise, "configured to" may generally encompass active components and / or inactive components and / or standby components.

[0080] Those skilled in the art will recognize that the terms used in this specification, generally, and in the appended claims in particular (e.g., the body of the appended claims), are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including, but not limited to," the term "having" should be interpreted as "having at least," the term "include" should be interpreted as "including, but not limited to," etc.). It will be further understood by those skilled in the art that if a specific number of claim recitations to be introduced are intended, such intent will be expressly recited in the claims, and that in the absence of such recitation, no such intent exists. For example, as an aid to understanding, the following appended claims may contain the use of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed as implying that the introduction of a claim recitation with the indefinite article "a" or "an" limits any particular claim containing such an introduced claim recitation to those claims that include only one such recitation, even when that same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should typically be construed to mean "at least one" or "one or more"), nor should the use of definite articles used to introduce claim recitations.

[0081] Moreover, even when a particular number of introduced claim recitations is explicitly recited, one of ordinary skill in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., an explicit recitation of "two recitations" without other modifiers typically means at least two recitations, or more than two recitations. Furthermore, in such cases where a convention similar to "at least one of A, B, and C, etc." is used, such structure is generally intended in the sense that one of ordinary skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include, but is not limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together). Conventions similar to "at least one of A, B, or C, etc." In such cases where is used, generally, such structure is intended in the sense that one of ordinary skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include, but is not limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It will be further understood by those of ordinary skill in the art that typically disjunctive words and / or phrases presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms, unless the context dictates otherwise. For example, the phrase "A or B" would typically be understood to include the possibilities of "A" or "B" or "A and B."

[0082] With respect to the appended claims, those skilled in the art will understand that the operations recited therein may generally be performed in any order. Also, while various operational flow diagrams are presented in sequences, it should be understood that various operations may be performed in other orders than those illustrated, or may be performed simultaneously. Examples of such alternative orderings may include overlapping, interleaving, interrupting, reordering, incremental, preparatory, supplementary, simultaneous, reverse, or other various orderings, unless the context dictates otherwise. Moreover, unless the context dictates otherwise, terms such as "responsive to," "related to," or other past tense adjectives are generally not intended to exclude such variations.

[0083] It should be noted that any reference to "one embodiment," "one aspect," "one example," "one example," etc. means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment," "in one embodiment," "in one example," and "in one example" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0084] Any patent application, patent, non-patent publication, or other disclosure material referenced herein and / or listed in any application data sheet is incorporated herein by reference to the extent that such material is not inconsistent with this specification. Thus, and to the extent necessary, the present disclosure as expressly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is referred to as being incorporated herein by reference but that conflicts with existing definitions, descriptions, or other disclosure material set forth herein, is incorporated only to the extent that there is no conflict between the incorporated material and the existing disclosure material.

[0085] The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "having"), "include" (and any form of include, such as "includes" and "including"), and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, a system that "includes," "has," "includes," or "contains" one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Similarly, an element of a system, device, or apparatus that "includes," "has," "includes," or "contains" one or more features possesses those one or more features, but is not limited to possessing only those one or more features.

[0086] The terms "substantially," "about," or "approximately," as used in this disclosure, unless otherwise specified, refer to an acceptable error for a particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined. In some embodiments, the terms "substantially," "about," or "approximately" refer to within 1, 2, 3, or 4 standard deviations. In some embodiments, the terms "substantially," "about," or "approximately" refer to within 50%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.05% of a given value or range.

[0087] In summary, numerous benefits resulting from employing the concepts described herein are described. The above description of one or more embodiments is presented for purposes of illustration and description. It is not intended to be exhaustive or limited to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more embodiments have been selected and described in order to illustrate the principles and practical applications, thereby enabling those skilled in the art to utilize the various embodiments and with various modifications suitable for the particular use contemplated. The claims submitted herein are intended to define the overall scope. The features of the technology disclosed in this specification are listed below. (Item 1) 1. A mold assembly configured to mold a wick, the mold assembly comprising: an expandable tube that is hydraulically expandable to an expanded shape, the wick mesh being configured to be wrapped around the expandable tube; 1. A molded shell assembly comprising: a first molded shell having a first recess defined therein; a second molded shell having a second recess defined therein, the first recess and the second recess cooperating to define an outer diameter of the wick, the expandable tube and the wick mesh being positionable between the first recess and the second recess; A molding assembly, wherein the expandable tube and the molding shell assembly are configured to deform a wick mesh and shape the wick based on hydraulic expansion of the expandable tube to the expanded shape. (Item 2) Item 14. The molding assembly of item 1, wherein the wick is configured to separate from the expandable tube upon the expandable tube transitioning to an unexpanded shape. (Item 3) Item 3. The molding assembly of item 2, wherein the wick is configured to separate from the expandable tube without chemical treatment. (Item 4) Item 1. The molded assembly of item 1, wherein the expandable tube comprises polyurethane. (Item 5) and a clamping plate assembly configured to clamp the first mold shell to the second mold shell, the clamping plate assembly comprising: a first clamping plate configured to abut the first mold shell; a second clamping plate configured to abut the second mold shell; and a fastener configured to clamp the first clamp plate to the second clamp plate. (Item 6) Item 1, further comprising a support tube positionable within the expandable tube, the support tube having pores defined therein, the pores configured to fluidly connect a pressure source to the expandable tube. (Item 7) Item 1, further comprising an end flange configured to couple the first formed shell to the second formed shell, the end flange having a hydraulic opening defined therein, the expandable tube configured to hydraulically expand to the expanded shape based on pressure applied through the hydraulic opening by a pressure source. (Item 8) Item 8. The mold assembly of item 7, wherein the end flange comprises a receiving area configured to receive therein an O-ring and a portion of the expandable tube not covered by the wick mesh. (Item 9) 1. A method of molding a wick with a molded shell assembly including an expandable tube, the method comprising: disposing a wick mesh around the expandable tube; placing the expandable tube and the wick mesh within a receiving area of ​​the molded shell assembly; coupling a first end flange to a first side of the molded shell assembly; connecting a second end flange to a second side of the molded shell assembly, the first end flange including a hydraulic opening defined therein, the hydraulic opening in fluid communication with the expandable tube; clamping the molded shell assembly with a clamp plate assembly; applying pressure to the expandable tube through the hydraulic opening with a pressure source to transition the expandable tube to an expanded shape and press the wick mesh against an inner surface of the molded shell assembly. (Item 10) 10. The method of claim 9, wherein applying pressure to the expandable tube comprises applying pressure to the expandable tube such that the expandable tube plastically deforms the wick mesh. (Item 11) transitioning the expandable tube to a contracted configuration; Item 11. The method of item 10, further comprising removing the wick from the expandable tube. (Item 12) Item 12. The method of item 11, wherein removing the wick from the expandable tube comprises removing the wick from the expandable tube without chemical treatment. (Item 13) 10. The method of claim 9, further comprising disposing the expandable tube around a porous support tube, wherein pores defined in the porous support tube are configured to fluidly connect the pressure source to the expandable tube. (Item 14) placing a first O-ring, a first portion of the porous support tube, and a first portion of the expandable tube not captured by the wick mesh into a first receiving area defined in the first end flange; 14. The method of claim 13, further comprising placing a second O-ring, a second portion of the porous support tube, and a second portion of the expandable tube not captured by the wick mesh in a second receiving area defined in the second end flange. (Item 15) 1. A mold assembly configured to mold a wick, the mold assembly comprising: 1. A wick assembly comprising: a porous support tube having pores defined therein; a wick assembly comprising: an expandable tube configurable between a contracted shape and an expanded shape, the expandable tube being disposed around the porous support tube and a wick mesh configured to be wrapped around the expandable tube; 1. A molded shell assembly comprising: a first molded shell having a first recess defined therein; a second molded shell including a second recess defined therein, the wick assembly being positionable between the first recess and the second recess; and a first end flange connectable to the first mold shell and the second mold shell, the first end flange comprising: a first receiving area configured to receive a first O-ring, a first portion of the porous support tube, and a first portion of the expandable tube therein; a hydraulic opening configured to fluidly connect a pressure source to the expandable tube; and a molded shell assembly comprising: a second end flange connectable to the first molded shell and the second molded shell, the second end flange comprising a second receiving area configured to receive therein a second O-ring, a second portion of the porous support tube, and a second portion of the expandable tube. (Item 16) Item 16. The mold assembly of item 15, further comprising means for preventing separation of the first and second molded shells when the expandable tube expands to an expanded shape. (Item 17) Item 16. The mold assembly of item 15, wherein the expandable tube comprises polyurethane. (Item 18) Item 16. The mold assembly of item 15, wherein the first recess and the second recess are configured to define an outer diameter of the wick. (Item 19) Item 16. The molding assembly of item 15, wherein the expandable tube is configured to deform the wick mesh and shape the wick based on the expandable tube transitioning to the expanded shape. (Item 20) 20. The mold assembly of claim 19, wherein the wick is configured to separate from the expandable tube without chemical treatment.

Claims

1. 1. A mold assembly configured to mold a wick, the mold assembly comprising: an expandable tube that is hydraulically expandable to an expanded shape, the wick mesh being configured to be wrapped around the expandable tube; 1. A molded shell assembly comprising: a first molded shell having a first recess defined therein; a second molded shell having a second recess defined therein, the first recess and the second recess cooperating to define an outer diameter of the wick, the expandable tube and the wick mesh being positionable between the first recess and the second recess; A molding assembly, wherein the expandable tube and the molding shell assembly are configured to deform a wick mesh and shape the wick based on hydraulic expansion of the expandable tube to the expanded shape.

2. The molding assembly of claim 1 , wherein the wick is configured to separate from the expandable tube upon the expandable tube transitioning to an unexpanded shape.

3. The molding assembly of claim 2 , wherein the wick is configured to separate from the expandable tube without chemical treatment.

4. The molding assembly of claim 1 , wherein the expandable tube comprises polyurethane.

5. and a clamping plate assembly configured to clamp the first mold shell to the second mold shell, the clamping plate assembly comprising: a first clamping plate configured to abut the first mold shell; a second clamping plate configured to abut the second mold shell; and a fastener configured to clamp the first clamping plate to the second clamping plate.

6. 2. The molding assembly of claim 1, further comprising a support tube positionable within the expandable tube, the support tube having a pore defined therein, the pore configured to fluidly connect a pressure source to the expandable tube.

7. 2. The mold assembly of claim 1, further comprising an end flange configured to couple the first mold shell to the second mold shell, the end flange having a hydraulic opening defined therein, the expandable tube configured to hydraulically expand to the expanded shape based on pressure applied through the hydraulic opening by a pressure source.

8. The mold assembly of claim 7 , wherein the end flange comprises a receiving area configured to receive therein an O-ring and a portion of the expandable tube not covered by the wick mesh.

9. 1. A method of molding a wick with a molded shell assembly including an expandable tube, the method comprising: disposing a wick mesh around the expandable tube; placing the expandable tube and the wick mesh within a receiving area of ​​the molded shell assembly; coupling a first end flange to a first side of the molded shell assembly; connecting a second end flange to a second side of the molded shell assembly, the first end flange including a hydraulic opening defined therein, the hydraulic opening in fluid communication with the expandable tube; clamping the molded shell assembly with a clamp plate assembly; applying pressure to the expandable tube through the hydraulic opening with a pressure source to transition the expandable tube to an expanded shape and press the wick mesh against an inner surface of the molded shell assembly.

10. 10. The method of claim 9, wherein applying pressure to the expandable tube comprises applying pressure to the expandable tube such that the expandable tube plastically deforms the wick mesh.

11. transitioning the expandable tube to a contracted configuration; The method of claim 10, further comprising removing the wick from the expandable tube.

12. The method of claim 11 , wherein removing the wick from the expandable tube comprises removing the wick from the expandable tube without chemical treatment.

13. 10. The method of claim 9, further comprising disposing the expandable tube around a porous support tube, wherein pores defined within the porous support tube are configured to fluidly connect the pressure source to the expandable tube.

14. placing a first O-ring, a first portion of the porous support tube, and a first portion of the expandable tube not captured by the wick mesh into a first receiving area defined in the first end flange; 14. The method of claim 13, further comprising placing a second O-ring, a second portion of the porous support tube, and a second portion of the expandable tube not captured by the wick mesh in a second receiving area defined in the second end flange.

15. 1. A mold assembly configured to mold a wick, the mold assembly comprising:

1. A wick assembly comprising: a porous support tube having pores defined therein; a wick assembly comprising: an expandable tube configurable between a contracted shape and an expanded shape, the expandable tube being disposed around the porous support tube and a wick mesh configured to be wrapped around the expandable tube; 1. A molded shell assembly comprising: a first molded shell having a first recess defined therein; a second molded shell including a second recess defined therein, the wick assembly being positionable between the first recess and the second recess; and a first end flange connectable to the first mold shell and the second mold shell, the first end flange comprising: a first receiving area configured to receive a first O-ring, a first portion of the porous support tube, and a first portion of the expandable tube therein; a hydraulic opening configured to fluidly connect a pressure source to the expandable tube; and a molded shell assembly comprising: a second end flange connectable to the first molded shell and the second molded shell, the second end flange comprising a second receiving area configured to receive therein a second O-ring, a second portion of the porous support tube, and a second portion of the expandable tube.

16. 16. The mold assembly of claim 15, further comprising means for preventing separation of said first and second molded shells when said expandable tube expands to an expanded shape.

17. The mold assembly of claim 15 , wherein the expandable tube comprises polyurethane.

18. The mold assembly of claim 15 , wherein the first recess and the second recess are configured to define an outer diameter of the wick.

19. The molding assembly of claim 15 , wherein the expandable tube is configured to deform the wick mesh and shape the wick upon the expandable tube transitioning to the expanded shape.

20. 20. The mold assembly of claim 19, wherein the wick is configured to separate from the expandable tube without chemical treatment.

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