WO2004063654A2

WO2004063654A2 - Thermal energy transfer panel

Info

Publication number: WO2004063654A2
Application number: PCT/US2004/000407
Authority: WO
Inventors: Paul A. Hurley
Original assignee: Hurley Paul A
Priority date: 2003-01-10
Filing date: 2004-01-10
Publication date: 2004-07-29
Also published as: WO2004063654A3

Abstract

Disclosed herein is are various energy transfer panel designs. Specifically exemplified herein is a thermally insulated storage container comprising at least one energy transfer panel integrated therein. The thermally insulated storage device allows the use of a cooling medium, such as ice, to chill a separate compartment of the device with the separate compartment coming into contact with the cooling medium.

Description

TITLE OF THE INVENTION THERMAL ENERGY TRANSFER PANEL FIELD OF THE INVENTION:

The present invention is generally directed to systems for the transfer of thermal energy and more specifically to a thermal-conducting panel constructed to efficiently transfer thermal energy from a specific heat source to the surrounding environment or to transfer thermal energy from one point to another in a thermally insulated storage device.

BACKGROUND:

Electrical and mechanical devices often create significant quantities of thermal energy. This thermal energy is typically created by inefficiencies of the device (either electrical resistance or mechanical resistance) and normally will have a negative effect on the performance or life expectancy of said devices. Electrical transformers and electrical motors are examples of thermal energy generating devices. Managing excessive thermal energy of these devices is required, especially as the size and power of said devices increase. Many different methods are typically employed to remove said thermal energy from said devices.

The simplest form of cooling is to rely on the surrounding environment for radiant and convection cooling. This method works well for very small motors and transformers, but as the size of the device increases (as the power output or power input increases) so does the waste heat. Generally, this increase of waste heat is much larger than the increase of the device itself (the surface area of the device does not increase at the same rate as the increased amount of waste heat). Some form of additional cooling must be used once the device creates more thermal energy than can be dissipated through surface convection and radiational cooling. The most basic approach is to increase the surface area of the device. This usually is accomplished by the addition of heat dissipation fins. One problem with this approach is the thermal conducting efficiency of the fin material. Generally, the thermal conducting efficiency of a material and the electrical conducting efficiency of a material are similar. Typically, a material that efficiently conducts electricity will efficiently conduct thermal energy. Gold, silver, copper and aluminum all to some degree efficiently conduct thermal energy (gold being the most efficient and aluminum the least efficient of this group). Most electric motor and transformer cases are made of steel. Compared with the above-mentioned thermal conducting metals, steel is a poor conductor of thermal energy.

The use of any of the above-mentioned materials as cooling fins for a steel cased devise creates several problems. One problem is the cost of the material itself; another is the attachment of dissimilar metals and corrosion of the fin and the case do to chemical reactions caused by the direct contact of dissimilar metals. Another problem with using dissimilar materials is the different thermal expansion rates. Because of these problems steel is typically the preferred heat dissipation fin material. Because of steel's poor thermal conducting capacity, the fin must be very thick. This causes the overall weight of the device to increase substantially. Still another problem with finning is in the way thermal energy is transferred through the fin. Thermal energy moves through the fin by means of temperature difference. This means that the temperature of the base of the fin (the part of the fin attached to the heat-generating device) must be hotter than the opposite end of the fin. Because of the need for a temperature difference throughout the fin, the overall temperature of the heat- generating device will be hotter than it would be if the fin material could conduct thermal energy without a temperature difference. Length of each fin is greatly impacted by this problem so normally a plurality of small fins would be used instead of a small number of very long fins.

Another method of cooling is to attach a fan directly to the heat-generating device to help dissipate the waste heat to the surrounding environment. Another method is to circulate a cooling medium through and/or around the heat-generating device and then cool said medium by means of a forced air or other heat sink material. A problem with these last two methods is the need for one or more separate pieces of equipment (a fan and/or a pump). Failure of the pump or fan would result in the overheating of the thermal energy-generating device. Thus, current approaches to heat dissipation are either inefficient or cost prohibitive or both. Accordingly, there is a need in the art for an inexpensive system that can efficiently transfer thermal energy while overcoming the problems inherent in the existing methods of heat transfer.

SUMMARY OF THE INVENTION

Described herein is a novel system for transferring thermal energy out of electrical transformers, electric motors and the like. In a preferred embodiment, the invention consists of one or more sheets of material, preferably metal, wherein at least one sheet is formed to have one or more indentations and/or bends. The sheet or sheets are welded or otherwise affixed together. The space between the sheet(s) is evacuated to decrease the pressure inside the system, and a small amount of working fluid, preferably water, is placed between the sheets into the now formed tubes. When the two sheets or folds of one sheet are sealed together, a plurality of tubes are formed by the indentions or bends m me sneet(s). Upon being subjected to thermal energy at one location of the system, the working fluid converts to a gas state that then releases its energy upon condensation at another location of the subject system. The present device provides an extraordinarily efficient means of transferring a quantity of energy from one location to another and permits uniform delivery of heat with very little temperature difference thereby reducing the operating temperature of the heat generating device compared with standard fin materials.

The system may be used in any environment; both indoors and outdoors, to efficiently transfer heat energy to and from, or within an object. The basic design disclosed is similar to thermosyphon radiators disclosed in previous art with several important modifications. One particularly useful application of the subject system is the cooling of transformers. Unlike previous applications of thermosyphon radiators, transformer cooling applications require the tubes (used to transport vapor and condensed liquid) to be aligned substantially vertical above and/or below eachother, instead of horizontally aligned (i.e. side to side). This is needed because large electrical transformers tend to be built in the form of a tube and a placed on their end. The transformer is filled with oil, which is used to transfer thermal energy from the transformer core to the transformer case. The hottest oil in the transformer would tend to rise to the top of the transformer case, which then requires effective cooling of said area. For optimal operation, each tube in the panel is individually sealed, evacuated and charged with the proper amount of working fluid. Several features must be included to insure proper operation of the thermal panel. One such feature involves creating watertight internal seals between each individual heat pipe. As mentioned above, in the preferred embodiment the tubes are aligned one on top of another. Gravity, capillary action and pressure differences will cause the working ^"fluid to migrate between the two sheets and finally pool at the bottom of the thermal panel. The panel must be configured so as to prevent the migration of the working fluid. This can be accomplished by implementing a gasket, sealant, laminate, coating, mechanical design or similar means would create the desired result. Another feature involves angling each tube to insure proper movement of the condensed working fluid toward the heat source. Another feature involves creating a single channel in the sheet that is perpendicular to the fluid tube channels and open to all said tubes. This single channel is used to evacuate all of the panels' fluid carrying tubes and to introduce working fluid into said tubes. A small tube with one end open to the outside environment is attached through the sheet 'and into the comiecting channel. This small tube is used to evacuate the panel and introduce the working fluid. Once the panel is evacuated and charged with working fluid, the small tube would be sealed from the outside environment. The panel would then be positioned so the working fluid would evenly pool in each fluid carrying tube. The connecting channel would then be crushed or sealed closed between each fluid carrying tube creating a plurality of individually sealed heat pipes.

In yet another embodiment, the subject invention pertains to a thermally insulated storage device that has integrated or attached to its inner walls a thermal energy transfer panel as described herein. Alternatively, the storage device may simply include one or more individual, conventional heat pipes in or attached to its walls.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1' is a schematic illustration of the side, front and top views of a cooling fin assembly according to the embodiment of the invention;

Figure 1 A is a schematic illustration of an embodiment similar to that shown in Figure 1 ' but with multiple cooling fins;

Figure 2 is a schematic illustration of an alternate embodiment of a cooling fin assembly attached to an externally mounted oil filled cooling fin of a transformer;

Figure 3 A is a schematic illustration of a method of preventing fluid migration inside a cooling fin assembly;

Figure 3B is a schematic illustration of an alternate method of preventing fluid migration inside a cooling fin assembly;

Figure 3C is a schematic illustration of an alternate method of preventing fluid migration inside a cooling fin assembly;

Figure 4' is a schematic illustration of an embodiment of a cooling fin assembly attached to a portable fuel cell powered thermal energy generator;

Figure 4 A is a schematic illustration of an embodiment of a cooling fin assembly attached to a portable fuel cell powered thermal and electric energy generator with the addition of a light, an electrical power output device and a radio;

Figure 4B is a schematic illustration of an embodiment of a cooling fin assembly attached to a portable fuel cell powered thermal and electric energy generator with the addition of an electric powered cooking surface;

Figure 5 is a schematic illustration of the side and top views of an embodiment of a thermal energy transfer panel integrated into an insulated storage device.

Figure 6 is a schematic illustration of the front view of an alternate embodiment of a thermal energy transfer panel integrated into an insulated storage device. The outer ^" thermally insulated shell is snown transparent for ease of view of the thermal energy transfer panel.

Figure 6 A is a schematic illustration of the side view of an alternate embodiment of a thermal energy transfer panel integrated into an insulated storage device. The outer thermally insulated shell is shown transparent for ease of view of the thermal energy transfer panel.

Figure 7 is a schematic illustration of a method of improving the flow characteristics of a working fluid in low temperature applications of a thermal energy transfer panel.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 ' shows the preferred design of a cooling fin assembly for transferring thermal energy from a transformer. The cooling fin assembly could also be used on electric motors or any other heat-generating devices including devices engineered specifically to create thermal energy such as a space heater. In the preferred embodiment the cooling fin assembly is comprised of a single sheet of formed and folded metal hermetically sealed to the outside surface of the heat source. In an alternate embodiment the cooling fin assembly would be comprised of 2 or more sheets of formed and folded metal hermetically sealed together to form a plurality of individually sealed tubes or chambers and then attached to a heat-generating device. It should be noted that the term chambers may include round or arcuate shaped chambers, or include other shapes including square, triangular, polygonal, etc. Figure 1 A shows the same transformer cooling fin assembly design but with multiple cooling fins. An alternative method for cooling oil filled transformers is to seal the formed sheet directly to an external-cooling fin as shown in Figure 2. ' iri either design, each tube ot the panel is an individual heat pipe. The working fluid (preferably water) pools at the lowest part of the tube in the fin and along the bottom of the tube formed against the transformer shell. When the temperature of the transformer shell exceeds the temperature of the fin, the working fluid will boil absorbing thermal energy from the transformer shell. This energy is then released along the cooling fin assembly as the working fluid condenses. The diameter of the tube is limited by the fluid dynamics of the working fluid. The tube diameter must be large enough to allow vapor travel in one direction while simultaneously allowing condensed working fluid to travel back along the tube to the heat source. The smaller the diameter the more efficient the cooling process.

Figure 3 A, 3B and 3C illustrate methods of preventing working fluid migration inside the cooling fin assembly. Each tube of the cooling fin assembly must contain a sufficient amount of working fluid to properly operate. Without some form of modification to the contact area of the pre-formed sheets, the working fluid will migrate downward over-time and render the panel inoperable.

Figure 4 illustrates an embodiment of a cooling fin assembly attached to a fuel cell powered portable space heater. Fuel cells are very efficient electrical energy producers but do still generate heat as a waste product. It is the intention of said embodiment to utilize both the electrical output and the thermal waste to heat an enclosed area such as a tent or small room. Current portable space heaters burn fuel in order to generate thermal energy. Carbon monoxide poisoning has always been a problem with these types of space heaters. The use of a thin wire centered in a reflective surface and powered by a battery is another type of portable space heater. Accidental fires have been known to start if a flammable item comes in contact with the super hot wire. Figure 4 schematically demonstrates a space heater that neither produces poisonous gases or operating temperatures high enough to cause combustion. Figure 4A illustrates additional features beyond those disclosed in Figure 4. These features include an electrical outlet so the user could utilize electrical energy for purposes other than space heating while utilizing the fuel cell's waste heat for space heating. Other features include the addition of a built in light and a built in radio. Figure 4B illustrates the addition of an electric powered heating surface.

Figure 5 illustrates the preferred embodiment of the integration of a thermal energy transfer panel into a segmented thermally insulated storage device. Ice or similar cooling medium is placed in one of the compartments. In the preferred embodiment, the smaller of the two or more compartments is used for the cooling medium. It is the puipose of the described embodiment to overcome cross contamination of food and or medicine and the cooling medium (ice or icy slush). The thermal energy transfer panel transfers thermal energy from the food and medicine storage area to the cooling medium without having the food and or medicine in direct contact with said cooling medium. Figure 6 and figure 6A illustrate another embodiment of a thermally insulated storage device with an integrated thermal energy transfer panel.

Figure 7 illustrates methods of improving the flow characteristics of the working fluid. This is very important when the operating temperature of the cooling fin is below 50 degrees Fahrenheit and when the working fluid is water. This is due to the low internal pressure of the cooling panel at or below this temperature. Static head pressure of the pooled working fluid will increase the temperature of boiling thereby decreasing the cooling efficiency of the thermal energy transfer panel.

Referring to the drawings, and particularly to Figure 1, there is diagrammatically shown the component parts of an evacuated system, generally r rό's ntb ''dt'^l OO^',whϊcl¹i'^,ltiϊϊ'Ii^,2ifes^' the thermal dynamic properties of evaporation and condensation of a working fluid to transfer thermal energy. In a preferred embodiment, the system 100 comprises at least one sheet of material and a small amount of working fluid preferably water 102 (only one tube is shown to have water but all tubes in the panel would normally have water), placed between the formed and sealed sheet. The sheet is constructed to have a plurality of bends or indentations 101 and 104 that form tubes when said sheet is folded onto itself and/or when it is sealed onto a heat-generating device. Channels 101 form the condensing portion of the panel and channels 104 form the evaporation portion of the panel. The channels 101 in the fin 103 are tilted to insure that the working fluid flows by gravity toward the heat- generating device. The sheet is preferably made of metal, but may be constructed of other malleable material such as glass, plastic, and the like. In a preferred embodiment a long piece of metal is obtained, and heated at certain points. The metal is then manipulated to form the plurality of bends 101 and 104, thereby forming a panel having both straight and bent sections without junctures. Alternatively, the panel can be made by molding processes commonly used in the art. Other alternative methods of making the subject panel can be readily understood by those skilled in the art. The formed sheet of material is then folded against itself such that a plurality of channels 101 and 104 are formed between the sheets. These channels may take the form of half circles in the case where one half of the sheet is indented and the other half remains flat; or a full circle, when both sides of the sheet are indented. These channels 101 and 104 become pathways for fluid or gas when folded against itself. The ends of the channels gradually taper back to the original flat material. In the preferred embodiment the tubes 101 and 104 are aligned one on top of another. The panel edges are sealed together by means of solder, welding, gluing or other means in " offlef to torm a hermetic seal. A single channel, perpendicular to the fluid tube channels and open to all said tubes, is also formed into the sheet prior to assembly 105. 105 shows the tube after it has been crushed flat. This single channel 105 is used to evacuate all of the panels' fluid caring tubes and to introduce working fluid into said tubes. A small tube (not shown) with one end open to the outside environment is attached through the sheet and into the connecting channel. This small tube is used to evacuate the panel and introduce the working fluid 102. Once the panel is evacuated and charged with working fluid, the small tube would be sealed from the outside environment. The form of the panel provides the dual function of both forming a large cooling fin or fins 103 and a plurality of individually sealed and charged heat pipes 101.

The amount and type of working fluid depends on the area of the panel and the temperature range of the panel. One significant advantage of the current system is that water is a feasible and preferred working fluid. Use of water alleviates all of the toxicity, pollution or fire concerns associated with using other types of working fluids such as ammonia, butane, ethanol, methanol, freon and other commercially available refrigerants that are known to be harmful to the environment.

Figure 1 A depicts the top view of the same transformer cooling fin design as figure 1 but with additional fins 103 and tube portions 101 and 104. Because each of the fin tubes 101 and case tubes 104 is one continuous tube per level, only one perpendicular tube 105 is needed. Tube 105 can be formed in any of the fins 103.

Figure 2 shows an embodiment of the previously disclosed panel design sealed directly to an externally mounted oil filled cooling fin instead of directly to the case of an electrical transformer. This embodiment could also be used in other heat dissipation applications. Referring to figure 2, there are diagrammatically shown the " component parts o± an evacuated system, generally represented at 200. In the preferred embodiment, panel 200 would be attached to an existing oil filled cooling fin 206. The existing oil filled cooling fin 206 would be attached to an oil filled transformer (not shown). The oil in the transformer is used to move thermal energy from the core of the transformer to the external cooling fin. Hot oil rises to the top of the transformer and flows into the cooling fin 200 by means of convective flow. Oil in the external fin, which is cooler than the hot oil from the transformer, sinks and flows back into the bottom of the transformer. The working fluid 202 boils when the oil passing through the external fin is hotter than the fin area 203. The fin tubes 201 are angled so as to improve the flow of condensed working fluid back to the heat source.

Gravity, capillary action and pressure differences will cause the working fluid to migrate between the two sheets and finally pool at the bottom of the thermal panel. The panel must be modified so as to prevent the migration of the working fluid. This can be accomplished by many different means. A gasket, sealant, laminate, coating, mechanical design or similar means would create the desired result. The surface of the heat-generating device must also have a gasket, sealant, laminate, coating, mechanical design or similar means so as to prevent the working fluid from migrating down between the contact points of the formed sheet and the transformer shell. The preferred method of preventing working fluid migration is to coat or laminate the entire inside surface of the panel including the surface of the thermal-generating device (not shown). The coating or laminate would eliminate fluid migration and protect the internal surfaces from corrosion. When corrosion is not a concern (if copper or some other corrosion resistant material was used) methods illustrated in figure 3A, 3B and 3C could be utilized. I ■^•rιgure y:Λ. illustrates a mecnanical seal. As shown in figure 3A, the formed sheet or sheets 301 have a mechanical contact seal shown as a series of small interlocking parallel channels 302. A variety of patterns or channel designs could be used to create the mechanical seal. When the panel is evacuated, external atmospheric pressure will compress the panels 301 together and compress the now formed mechanical seal. Further strengthening of the mechanical seal would be accomplished by crimping, crushing or welding the interlocking channels after evacuation of the panel. This would allow the panel to operate at an internal pressure above the pressure of the surrounding environment.

Figure 3B illustrates of method of sealing utilizing a gasket 303 (the gasket 303 could be replaced with a laminate, coating or similar means). The gasket 303 would be placed between sheets 301 or between a single sheet 301 and the outside surface of a heat-generating device (not shown) only at points of contact between said sheet or sheets.

Figure 3C illustrates a method of sealing utilizing a single sheet of material. The sealing sheet 304 is placed between sheets 301 prior to assembly. Once the panel has been sealed and evacuated, the sealing sheet 304 is compressed between sheets 301, forming a plurality of individual seals 305.

Figure 4 illustrates a fuel cell powered space heater utilizing a thermal energy transfer fin 401. The thermal energy fin 401 is of the same design as the fin described in figure 1. The fuel cell (not shown) is attached to the inside of the space heater shell 402 such that waste heat generated by the fuel cell during electrical generation will efficiently transfer into shell 402 and then into the fin assembly 401. The electrical output of the fuel cell is used to supply energy to heating strips or heating elements (not shown) located in or directly on the inside surface of the shell 402. Vent ^" openings 4m pro ι'de^""a p th ay for air to enter the inside of the shell 402. Air (oxygen) is necessary to the operation of the fuel cell. Vent openings are also located on top of the shell (not shown) so as to facilitate convective air flow throughout the inside of the space heater thereby improving air flow over the surface of the fuel cell. The fuel for the fuel cell is also located inside the space heater shell (not shown). A control-valve or switch 403 is used to turn on the space heater. Said control- valve or switch 403 could also serve as a thermostat control giving the user control over the amount or level of thermal output. Fuel cells are typically powered with Hydrogen. Water is formed when Hydrogen and Oxygen combine. The heater base 405 also serves as water collector and stores said water until the user drains or uses the water. Draining is accomplished by means of a valve 406.

Figure 4 A depicts additional features to the embodiment described in figure 4. One such feature is an integrated light 407 with an on and off switch 408. Switch 409 has an addition position labeled as "power". When switch 409 is set to the "power" position, electrical energy normally used to power the heater's heat strip or element would instead be routed to an electrical outlet 411. Another feature is the addition of an integrated radio 410. In the preferred embodiment, both the light 407 and the radio 410 would have electrical energy supplied even if switch 409 is not set to "power". Also in the preferred embodiment, the electrical output of the fuel cell would be in DC and would than pass through an inverter (not shown) for conversion to AC.

Figure 4B depicts the addition of an electric powered cooking surface 412 to the embodiment shown in figure 4A. Switch 409 has a position labeled "cook". When switch 409 is set to "cook", electric energy normally routed to the internal heating strip or element is redirected directly to cooking surface 412. The addition of a drip or spill tray 413 keeps the fins from being contaminated. ^' Figure 5 depicts a thermally insulated storage device generally shown as 501. In the preferred embodiment, a thermal energy transfer panel 502 is integrated into the inside walls of a storage device 501. Said thermal energy transfer panel 502 could be made to slide into an existing storage device as an after market device. The storage device 501 is separated into two or more compartments by means of a solid partition 503 (only one partition is shown, used to form two compartments). In the preferred embodiment, partition 503 is made of a thermally conductive material such as copper or aluminum. Partition 503 could be made from any material that is strong enough to handle the pressure of the cooling medium and that will effectively separate the cooling medium from the food and or medicine storage area. Partition 503 could be moveable or formed as part of the storage device 501. In the preferred embodiment, the thermal energy transfer panel 502 completely encircles the interior wall of the storage device 501. One familiar with the working processes of the thermal energy transfer panel 502 will see that modifications to the length or height of said cooling panel 502 would change the efficiency of the device but not the overall intent of the invention. The operation of the thermal energy transfer panel 502 depends on the proper flow of the working fluid 504 (shown in one tube of the thermal energy transfer panel but is present in all the tubes of the thermal energy transfer panel) as both a liquid (as shown) and as a gas. To help insure the proper flow of the working fluid 504 when in liquid form, thermal energy transfer panel 502 is tilted lower on the evaporation end 505 than the condensing end 506. The addition of a pair of moveable legs or similar device generally shown as 507 would enable the user to choose which compartment to use for storing the cooling medium. If the moveable legs 507 are retracted into the bottom of the storage device 501 then section 505 would be the evaporator section and section 506 would be the condensing section. If the moveable ^" legs 507 are extended down from the bottom of the storage device 501 then section 505 would be the condensing section and section 506 would be the evaporator section. The addition of a level or similar angle indicator generally shown as 508 would allow the user to determine the angle of the storage device.

In another embodiment (not shown), a solid-state cooling device (not shown) would be attached directly to the thermal energy transfer panel 502. The solid-state cooling device would either replace the cooling medium (in which case, the partition 503 could be removed) or be used to maintain the cooling capacity of the cooling medium when electrical power is available (in which case the partition 503 would remain).

Figure 6 illustrates the front view of a thermally insulated storage device generally shown as 601. The device 601 is shown with the opening (the door is not shown) but the opening could be made in the top. A thermal energy transfer panel 602 is integrated into the inside surface of the storage device 601. A separate area of the storage device 601 is used to store the cooling medium and is generally labeled 603. The cooling medium stored in compartment 603 is in thermal contact with the back of the thermal energy transfer panel 602. This area of the thermal energy transfer panel is the condensing section. The rest of the thermal energy transfer panel 602, not in direct contact with the cooling medium is the evaporation area of said panel assembly. Thermal energy transfer panel 602 is designed so the area of the panel in thermal contact with the cooling medium, generally shown as 604, which forms the condensing are of the panel, is at a higher elevation than the area of the panel used as the evaporator, generally shown as 605. Figure 6A illustrates the side view of the embodiment described in figure 6. The cooling medium storage area 603 has a valve or similar device 606 so the user can drain the area 603. Figure 7 illustrates a cross sectional view of the thermal energy transfer panel used in a thermally insulated storage device. In the preferred embodiment, the cooling panel assembly incorporated into the thermally insulated storage devices shown in figure 5 and figure 6 is comprised of a flat sheet 701 and a formed sheet 702. The flat sheet 701 is placed toward the interior of the storage device. In all the embodiments illustrated above, the preferred working fluid is water and the preferred cooling medium is ice.

In all the embodiments of the thermal energy transfer panel discussed above, proper panel orientation in respect to the plane of the earth is important to said panel's operation due to the need to keep the working fluid (as a liquid) as close to the heat source as possible. Figure 5 describes one angle of orientation and of methods to control or monitor such orientation. Figure 7 shows an enlarged area generally shown as 704. 704 illustrates a method of containing the working fluid close to the evaporation point 705 by forming a small channel or indentation in the one or both of the thermal energy transfer panel sheets generally shown as 706 (only one sheet is shown to have such a channel). This modification is necessary when the panel assembly is incorporated into a portable thermally insulated storage device such as the embodiment shown in figure 5 or 6, or when the device shown in figure 5 or 6 is installed in moveable object such as a boat.

There are several problems that must be addressed when using water as a working fluid at low temperatures. One such problem is pressure drop of the vapor as it flows inside the thermal energy transfer panel tube or tubes. This problem can be addressed by using a circular form in the formed side of the panel. Another problem is static head pressure of the pooled liquid working fluid. This problem can be addressed by roughing the inside surface of one or both of the thermal energy transfer " panel assemmy'srϊeet of 'sheets'; generally shown as 703. This will help to break the surface tension of the working fluid thereby decreasing the height of the pooled fluid and thereby decreasing the static head pressure of said fluid. Another embodiment of a thermally insulated storage device is to place the thermal energy transfer panel so the tubes are arranged so that they are aligned substantially horizontal to the plane of the earth instead of parallel as shown in the above embodiments. This change of orientation would allow the cooling medium to located in the top or lid of the device.

In an alternate embodiment of a storage device, the chamber in the panel may be substantially vertical such that the run from a top to bottom direction respective to the storage device. For example, Figure 8 shows an end cross-section of such a storage container 800. The vertical chambers 815 and 814 are shown running from the bottom to top of storage container 800. The bottom of the storage container has ice 810 disposed therein. The condensing region of the chamber containing the fluid in liquid state 817 is on shown at the bottom of the chamber. Fluid runs down the chamber by gravity. In order to facilitate movement of the fluid to the flashing portion of the chamber 814, the chamber 814 comprises a wick 816, which draws the fluid up and drips it onto the panel at the top. The circle A, blown up in Figure 9 illustrates the operation of the wick 816. Further, as shown in Figure 8, the panel with vertically running chambers is best tilted inward to cause the water to run or drip onto the panel rather than dropping straight down. This allows the liquid to flash to gas state as it comes into contact with the chamber walls.

Figure 12 shows a top view of a storage container similar to that shown in Figure 5. However, the partition 1215 between the first interior portion 1225 and the second interior portion 1230 (where food and beverages are stored for chilling) is curved or arched into the first interior portion. This influences the ice 810 to push outward toward the paϊteTs 1^'205^'and 1210 so that optimal ice to panel contact is encouraged. Those skilled in the art will appreciate that other configurations of the partition other than curving can be achieved to influence the ice in an outward direction, such as, but not limited to, triangulating the partition.

Figure 11 shows a cross-sectional side view of a chamber of a panel similar to that shown in the storage container illustrated in Figure 5 A. The representative chamber shows an embodiment where a wick 1115 can be positioned in the chamber to assist the proper transfer of fluid in liquid state from the condensing portion of the chamber 1110 to the flashing portion of the chamber, divided by the imaginary boundary 1130. The wick is preferably angled such that it is close to the bottom of the chamber in the condensing portion 1110 and near the top of the chamber at the flashing portion of the chamber. The wick 1115 carries fluid from the pool of fluid at the condensing portion of the chamber 1110 and drips the fluid 1120 onto the panel.

Figure 10 shows an alternative method to make an assembly of separately evacuated chambers containing an amount of working fluid. According to this alternative method, a pipe 1020 is evacuated followed by the infusion of an amount of fluid, or vice versa. The pipe 1020 is then crushed to form a seal 1010 between the sealed chamber 1015 and the remainder of the pipe. This process can be repeated to form a series of sealed chambers containing fluid, in a "sausage-link" type fashion. Once the desired amount of chambers are formed, they can be bent at the sealed portion to form an assembly of chambers running along side each other, or some other desired configuration. Those skilled in the art will recognize that any number of desired configurations can be achieved using this technique. " One knowledgeable m the are will recognize that the examples and embodiments described herein are for illustrative purposes only and that various modification or changes in light thereof will be suggested to persons having knowledge in the field and are to be included within the spirit and purview of this application and the scope of the appended claims.

Claims

I Claim:

1. A thermally insulated storage container comprising a first interior portion and a second interior portion; and at least one energy transfer panel disposed in said storage container such that it spans from said first interior portion to second interior portion; wherein said energy transfer panel comprises two or more individually sealed chambers containing a fluid; and wherein said energy transfer panel transfers energy from said first interior portion to said second interior portion; or vice versa.

2. The thermally insulated storage container of claim 1, wherein said two or more energy transfer panel is integrated into at least one wall of said thermally insulated storage container.

3. The thermally insulated storage container of claim 1, wherein said first interior portion and said second interior portion are divided by a partition.

4. The thermally insulated storage container of claim 1, wherein a cooling medium is provided in the second interior portion of the storage container. ^" 5.^' The thermally insulated ^"storage container of claim 1, wherein said two or mc sealed chambers are aligned in a substantially horizontal direction one on top of t other.

6. The thermally insulated storage container of claim 1 , wherein said two or mc sealed chamber are aligned in a substantially vertical direction one next to the other

7. The thermally insulated storage container of claim 1, wherein said two or mc sealed chambers each comprise a wicking material disposed therein to assist trans:! of fluid in a liquid state.

8. The thermally insulated storage container of claim 1, wherein said flu changes state from liquid to gas as it is transferring thermal energy.

9. The thermally insulated storage container of claim 1, wherein each chamber arranged such that in use the fluid contained in each chamber when in liquid foi migrates towards the first portion of each chamber.

10. The thermally insulated storage container of claim 1, wherein the stora container is provided with a level indicator to indicate the relative levels of the fii and second portions of each chamber.

11. The thermally insulated storage container of claim 1, wherein the stora container is provided with one or more supports to adjust the relative levels of the fii and second portions of each chamber. ^" 127 ^" The thermally insulated storage container of claim 11, wherein the one or more supports are one or more retractable legs.

13. The thermally insulated storage container of claim 1, wherein the two or more chambers are elongate and at least a portion of a cross-section of the one or more chambers is curved.

14. The thermally insulated storage container of claim 1, wherein at least a portion of the inside surface of the two or more chambers is rough.

15. The thermally insulated storage container of claim 1, wherein a mechanical seal is provided between each chamber.

16. The thermally insulated storage container of claim 1, wherein the two or more chambers is made from metal.

17. The thermally insulated storage container of claim 1, wherein the at least one energy transfer panel is constructed from at least one sheet of material arranged to have a plurality of bends, curves or indentations formed therein to form one or more chambers.

18. A thermally insulated storage container comprising a first interior portion and a second interior portion; and two or more individually sealed chambers disposed in said storage container to span from said first interior portion to second interior portion; wherein said two or more individually sealed chambers contain a fluid.

19. The storage container of claim 18, wherein said individually sealed chambers are individual heat pipes.

20. A method of making an assembly of individually sealed chambers comprising a) obtaining a pipe; b) evacuating said pipe; c) infusing fluid into said pipe; and d) sequestering an amount of said fluid in a portion of said pipe to form a first sealed chamber.

21. The method of claim 20 further comprising infusing fluid into said pipe an additional time after said first sealed chamber is formed; and sequestering an amount of said fluid in a portion of said pipe to form a second sealed chamber.

22. The method of claim 20, wherein said sequestering comprises crushing the walls of said pipe to form a seal between said first sealed chamber and the remainder of said pipe.

23. The method of claim 21, wherein said first sealed chamber is bent respective to the remainder of said pipe such that the first sealed chamber aligns alongside said remainder of said pipe.