HEAT PIPE SYSTEM HAVING COMMON VAPOR RAIL FOR USE IN A VENTILATION SYSTEM
A heat transfer system is adapted for transferring heat between two different ducts in a ventilation system. The system has a heat pipe having a plurality of conduits. Each conduit including an evaporator section extending laterally from a first open end of the respective conduit, a condenser section extending laterally from a second open end of the respective conduit, and a liquid return section. The liquid return section of at least one conduit being distinct from the liquid return section of another of the conduits. A common vapor manifold is in fluid communication with and extends between the first and second open ends of each of said plurality of conduits so vapors produced in the evaporator sections can flow from the first open ends through the common vapor manifold to the second open ends without flowing through the conduits.
This application claims priority to U.S. provisional application No. 61/436,076 filed Jan. 25, 2011, the entire contents of which are hereby incorporated by reference.
FIELD OF INVENTIONThe present invention relates generally to passive heat transfer devices and more particularly to heat pipes, which are closed loop systems using the high heat of evaporation/condensation associated with a phase changing working fluid to efficiently transfer large amounts of heat and which require no or only small energy input.
BACKGROUNDHeat pipes are closed loop heat exchangers that rely on a phase change of a working fluid to absorb heat by evaporation and release heat by condensation. A liquid working fluid (e.g., water, Freon, or the like) is vaporized in the evaporator portion of a heat pipe using heat absorbed from the environment. The vapor flows into the condenser portion of the heat pipe where it is condensed, releasing heat into the environment. Liquid condensed in the condenser is returned to the evaporator (e.g., by gravity, capillary action, pump, etc.) where it is evaporated again. In use the working fluid is continuously vaporized in the evaporator portion of the heat pipe and continuously condensed in the condenser portion of the heat pipe such that heat is absorbed from the environment by the evaporator, transferred to the condenser, and then released into the environment by the condenser. This process cools the environment surrounding the evaporator and heats the environment surrounding the condenser. Heat pipes can be extremely efficient at transferring large amounts of heat and can operate with only a limited difference between the temperatures of the evaporator and condenser portions of the system. Heat pipes also require no moving parts and typically require little or no maintenance.
One practical application for heat pipes is in de-humidification systems that pre-cool air in the inlet stream of a cooling coil (e.g., in the HVAC system for a commercial or residential building) and re-heat the outlet air stream from the cooling coil. The heat pipe can be configured to extend from one side of the cooling coil to its opposite side so the evaporator portion is in the cooling coil inlet stream and the condenser portion is on the opposite side of the cooling coil in the cooling coil outlet stream. For example, heat pipes can wrap around the sides and/or over the top of the cooling coil so the evaporator portion of the heat pipe is in the inlet stream and the condenser portion of the heat pipe is in the outlet stream. Pre-cooling the air as it enters the cooling coil allows the cooling coil to cool the air to a significantly lower temperature without using much if any additional energy. The overly cooled output air stream from the cooling coil is then heated by the condenser portion of the heat pipe system to a comfortably cool temperature. Over cooling the air in this manner increases the amount of moisture condensed from the air stream as it flows through the cooling coil. This combination of heat pipe and cooling coil provides a low cost, low maintenance dehumidification system.
Heat pipes can also be used to recover heat that would otherwise be lost in exhaust from an HVAC system during cold weather. For example, a heat pipe can be installed in the duct system of an HVAC system so the heat pipe extends into two adjoining ducts, one of which is being used to exhaust warmer stale air from the building and the other of which is used to convey cooler fresh air from outside the building to the HVAC system. Heat from the warm exhaust is captured by evaporation of the working fluid in the part of the heat pipe exposed to the exhaust and transferred to the cool inlet air by condensation of the working fluid in the part of the heat pipe exposed to the inlet stream. Thus, heat that would otherwise be lost to the outside of the building is used to pre-heat the cool inlet air, which means less energy is required by the heater of the HVAC system to heat the fresh air to a comfortable temperature. The heat pipes can be designed so when the cooling coil is operating in warm weather heat is transferred from the relatively warm inlet air to relatively cool stale exhaust air. Using the heat pipes to recapture heat from the warm exhaust in cold weather and recapture coolness from the cool exhaust in warm weather reduces the load on the heater and cooling coil and reduces energy required by the HVAC.
Various improvements to the prior art heat pipes are been made and will be described in the detailed description below.
SUMMARYOne aspect of the invention is a heat transfer system adapted for transferring heat between two different ducts in a ventilation system. The system comprising a heat pipe. The heat pipe has a plurality of conduits. Each conduit includes an evaporator section extending laterally from a first open end of the respective conduit, a condenser section extending laterally from a second open end of the respective conduit, and a liquid return section. The liquid return section for each conduit is connected to the evaporator section at a position away from the first open end and connected to the condenser section at a position away from the second open end so the evaporator and condenser section are in fluid communication with one another through the liquid return section for flow of liquid condensed in the condenser section to the evaporator section. The liquid return section of at least one conduit is distinct from the liquid return section of another of the conduits. The heat pipe includes a common vapor manifold in fluid communication with and extending between the first and second open ends of each of said plurality of conduits so vapors produced in the evaporator sections can flow from the first open ends through the common vapor manifold to the second open ends without flowing through the conduits.
Another aspect of the invention is a heat transfer system adapted for transferring heat between two different ducts in a ventilation system. The system includes a heat pipe. The heat pipe has first and second sets of conduits. Each set of conduits includes a plurality of conduits extending between open ends and spaced vertically from one another. The conduits of the first set are in generally side-by-side relation with the conduits of the second set and spaced laterally from the conduits of the second set. The heat pipe a first vapor manifold comprising a leg at one end of the conduits of the first set, another leg at an opposite end of the conduits of the second set, and a vapor passage extending between and in fluid communication with the legs of the first manifold. The vapor passage of the first vapor manifold extends between the first and second sets of conduits so vapor can flow between the ends of the conduits of the first set and the opposite ends of the conduits of the second set through the first vapor manifold without flowing through any conduits of said first and second set of conduits. The heat pipe has a second vapor manifold comprising a leg at one end of the conduits of the second set, another leg at an opposite end of the conduits of the first set, and a vapor passage extending between and in fluid communication with the legs of the second manifold. The vapor passage of the second vapor manifold extends between the first and second sets of conduits so vapor can flow between the ends of the conduits of the first set and the opposite ends of the conduits of the second set through the second vapor manifold without flowing through any conduits of said first and second set of conduits
Other objects and features will in part be apparent and in part pointed out hereinafter.
Corresponding reference characters indicate corresponding parts throughout the drawings.
DETAILED DESCRIPTIONReferring to
As illustrated in the drawings, the liquid return section 113 for each conduit 103 is connected to the evaporator section 105 at a position away from the open end 107 of the evaporator section. For example, the liquid return section 113 is suitably connected to the evaporator section 105 at an end of the evaporator section opposite the open end 107. The liquid return section 113 is also connected to the condenser section 109 at a position away from the open end 111 of the condenser section (e.g., at an end of the condenser section opposite the open end 111 of the condenser section) so the evaporator section 105 and condenser section of each conduit 103 are in fluid communication with one another through the respective liquid return section. The liquid return section 113 of at least one conduit 103 is distinct from the liquid return section of another of the conduits. As illustrated, for example, each conduit 103 has its own liquid return section 113, meaning the liquid return section for each conduit is distinct from the liquid return sections of all the other conduits.
The evaporator sections 105, condenser sections 109, and liquid return sections 113 are each suitably substantially straight sections of the respective conduit 103, although this is not required to practice the invention. The sections 105, 109, 113 can be connected to one another using a 90 degree elbow connector or other suitable connector. The conduits 103 could also be formed by bending a single segment of pipe to produce the various sections 105, 109, 113 of the conduit. The evaporator sections 105 of the conduits 103 suitably have a horizontal orientation. At least a portion of the condenser section 109 for each conduit 103 is at an elevation higher than the elevation of the evaporator section 105 of the respective conduit 103. For example, as illustrated in
Although the embodiment illustrated in the drawings has a configuration in which gravity drives or assists flow of condensed liquid L through the heat pipe 101 to the evaporator sections 105, condensed liquid can be returned to the evaporator portion of a heat pipe without any gravity assistance and/or against gravity using various internal wicking features and/or pumps known to those skilled in the art without departing from the scope of the invention.
As illustrated in
The heat pipe 101 is suitably configured so the evaporator sections 105 are positioned on one side of a space 131 for receiving a cooling coil 135 (
The conduits 103 are suitably made of relatively long narrow tubing. For example, the conduits 103 are suitably made of tubing no larger than 1 inch tubing, more suitably no larger than ⅝ inch tubing, more suitably no larger than ½ inch tubing and can in some cases be made of tubing no larger than ⅜ inch tubing. As illustrated in
The overall length of the flow path through the conduits 103 from the condenser opening 111, through the condenser section 109, liquid return section 113, and evaporator section 105 to the evaporator opening 107 is suitably in the range of about 50 inches to about 300 inches, more suitably in the range of about 60 to about 250 inches, more suitably in the range of about 100 to about 250 inches, more suitably in the range of about 125 to about 225 inches, and still more suitably in the range of about 150 to about 200 inches, with each of the foregoing lengths being suitable when the conduits are made from ½ inch tubing. Those skilled in the art will recognize the lengths described above for the conduits and the various parts thereof are fairly long flow paths for a heat pipe made of ½ inch tubing. Again, if larger tubing is used, the lengths can be increased even more without experiencing a significant loss in efficiency. For example, when the tubing is ⅝ inch diameter tubing, the overall length of the flow path through the conduits 103 from the condenser opening, through the condenser section 109, liquid return section 113, and evaporator section 105 to the evaporator opening 107 is suitably in the range of about 100 inches to about 500 inches, more suitably in the range of about 200 inches to about 500 inches, and still more suitably in the range of about 200 inches to about 400 inches. As another example, when the tubing is ⅜ inch diameter tubing, the overall length of the flow path through the conduits is suitably in the range of about 12 inches to about 200 inches, more suitably in the range of about 12 inches to about 100 inches, and still more suitably in the range of about 12 inches to about 60 inches, and still more suitably in the range of about 24 inches to about 60 inches. As still another example, when the tubing is in the range of about 5/16 to 7 mm diameter tubing, the overall length of the flow path through the conduits is suitably in the range of about 12 inches to about 50 inches. It costs substantially more to make heat pipes using larger diameter tubing than it does with smaller diameter tubing, so it is desirable to use the smallest diameter tubing that does not result in an unacceptably inefficient heat pipe. But the improvements described herein can also improve the efficiency for heat pipes in which the dimensions for the lengths and diameters of the conduits vary from those listed above within the scope of the invention.
The heat pipe 101 also has a common vapor manifold 151 in fluid communication with the open ends 107, 111 of each of said plurality of conduits 103 and extending between the open ends of the conduits so vapors V produced in the evaporator sections 105 can flow from the open ends 107 of the evaporator sections 105 through the common vapor manifold to open ends 111 of the condenser sections 109 without flowing through the conduits. Because the vapor V can return to the condenser sections 109 without flowing through the conduit, there is much less resistance to flow of liquid from the condenser sections to the evaporator sections 105 because counterflow of vapor and liquid L in the conduits 103 is greatly reduced or eliminated. The common vapor manifold can have many different configurations within the broad scope of the invention. As illustrated, the common vapor manifold 151 is an inverted U-shaped conduit having a generally upright evaporator leg 153, a generally upright condenser leg 155, and a generally horizontal vapor passage 157 connecting the legs to one another so they are in fluid communication with one another through the vapor passage. The evaporator leg 153 and the condenser leg 155 are suitably substantially straight (e.g., vertical) sections of tubing. The vapor passage 157 is also a substantially straight section of tubing having the same diameter as the legs 153, 155. Although the legs and vapor passage of the manifold are straight in the illustrated embodiment, other configurations are possible within the broad scope of the invention. The vapor passage 157 can be connected to the legs 153, 155 of the vapor manifold 151 using a 90 degree elbow connection or other suitably connecting means. Similarly, a single piece of tubing can be bent into an inverted U-shape to form the common vapor manifold 151 within the scope of the invention.
The tubing for the common vapor manifold 151 suitably has a diameter that is larger than the diameter of the conduits 103, as in the illustrated embodiment. In one embodiment, the conduits 103 can be made from 0.5 inch or ⅜ inch copper tubing while the common vapor manifold 151 is made from larger diameter ⅝ inch or 0.5 inch copper tubing, respectively. However, the cross sectional flow area of the vapor manifold 151 can be much larger than described above or be the same or smaller than the cross sectional flow area a conduit 103 within the scope of the invention. It is also understood the conduits 103 and manifold 151 are not required to have any particular cross sectional shape within the broad scope of the invention.
The open ends 107 of the evaporator sections 105 open into the evaporator leg 153 of the manifold 151. The open ends 111 of the condenser sections 109 open into the condenser leg 155 of the manifold 151. In the illustrated embodiment, the evaporator leg 153 of the common vapor manifold 151 extends to a position that is higher in elevation than the highest of the open ends 107 of the evaporator sections 105. For example, the manifold 151 suitably extends a distance H1 (
When the cooling coil 135 is on, air flows into the cooling coil and is cooled. Meanwhile, the evaporator sections 105 of the heat pipe 101 are exposed to the relatively warm air flowing into the cooling coil 135, represented in
As this is occurring, the condenser sections 109 are exposed to the cold outlet air stream from the cooling coil 135, represented by arrows B in
Because the common vapor manifold 151 allows vapors evaporated in the evaporator sections to flow to the condenser sections through the vapor manifold, there is less resistance to flow of liquid L through the conduits 103 to the evaporator sections 105 and there is less resistance to flow of vapor V to the condenser sections 109 because of the relative absence of counter flowing vapor and liquid in any section of the heat pipe 101. This increases the speed at which vapor V and liquid L flows through the heat pipe 101 and thereby allows the heat pipe 101 to perform efficiently even when the overall length of the conduits 103 is relatively long and the inner diameter of the conduits is relatively small (e.g., as described above). Moreover, the heat pipe 101 can perform efficiently with a relatively low charge of working fluid. For example, the charge of working fluid can suitably be in the range of about 15 percent to about 60 percent, more suitably in the range of about 15 percent to about 45 percent, more suitably in the range of about 15 percent to about 30 percent, and still more suitably in the range of about 20 percent to about 30 percent. In other examples, the interior surface of the tubing has grooves (which those skilled in the art will recognize aids flow of liquid through the tubing by capillary action) and the charge of working fluid can suitably be in the range of about 20 percent to about 50 percent, more suitably in the range of about 20 percent to about 45 percent, more suitably in the range of about 25 percent to about 40 percent, and still more suitably in the range of about 25 to 35 percent. Grooved tubing typically works better with a slightly larger charge of working fluid compared to tubing that is smooth on the inside. As further examples, the charge of working fluid is suitably less than about 40 percent, still more suitably less than about 35 percent, and still more suitably no more than about 30 percent. As those skilled in the art know, the amount of charge is the weight of working fluid (liquid+vapor) in the system expressed as a percentage of the weight of liquid phase working fluid that would completely fill the interior volume of the heat pipe. It is understood that larger charges than those specified above may be used within the broad scope of the invention. Accordingly, the performance of the heat pipe 101 can be equivalent to conventional heat pipe having significantly more expensive larger diameter tubing for the conduits and requiring a higher volume of working fluid. It is understood the improvements described herein can also improve efficiency of the heat pipes with the charge of working fluid varies from the amounts described above without departing from the scope of the invention.
As illustrated in
Another embodiment of a heat pipe, generally designated 101″′, is illustrated in
The evaporator sections 105″′ and condenser sections 109″′ are suitably horizontal (e.g., perfectly horizontal or substantially free of any incline), as illustrated. Each evaporator section 105″′ is suitably doubled back in such a way that the end 107″′ of the evaporator section is spaced inward from the end of the liquid return section 113 connected to the evaporator section. Each condenser section 109″′ is suitably doubled back in such a way that the end 111″′ is spaced outward from the end of the liquid return section that is connected to the condenser section. Accordingly, when the heat pipe 101″′ is installed for use with cooling coil 135, each evaporator section 105″′ includes a first portion 105a″′ adjacent the opening 107″′ and a second portion 105b″′ remote from the opening 107″′ and upstream of the first portion in the cooling coil intake stream. Likewise, each condenser section 109″′ includes a first portion 109a″′ adjacent the opening 111″′ and a second portion 109b″′ remote from the opening 111″′ that is upstream of the first portion in the flow out of the cooling coil. The evaporator leg 153″′ of the common vapor manifold 151″′ is positioned inside the portions 105b″″ of the evaporator sections 105″′ that are remote from the open ends 107″′. The condenser leg 155″′ of the common vapor manifold 151″′ is positioned outside the portions 109b″′ of the condenser sections 109″′ that are remote from the open ends 111″′. When the heat pipe 101″′ is in use, this arrangement causes temperature gradients to form in the conduits 103″′ that pump the working fluid through the heat pipe 101″′. In particular, evaporator portion 105b″′ will be warmer than portion 105a″′ and condenser portion 109a″′ will be warmer than portion 109b″′. The thermal gradients pump working liquid L from the warmer portion toward the cooler portion.
Another embodiment of a heat pipe, generally designated 201, is illustrated in
One embodiment of system 271 including a plurality of the heat pipes 201 is illustrated in
The system 271 can be installed in the duct system 291 of an HVAC (not shown) as illustrated schematically in
In winter, the system 271 can be operated in heat recovery mode by reversing the direction of heat transfer through the heat pipes 201. For example, the stale air from inside is now being vented to the exterior through the duct 295 is now relatively warmer while colder fresh air from the exterior of the building is conveyed to the HVAC through the adjacent duct 293. Because of the reversal of the direction of the temperature gradient between the sides of the system 271, what was the evaporator array 275 in the summer now functions as a condenser array and what was the condenser array 281 in the summer now functions as an evaporator array. The warm exhaust air flowing through the exhaust duct 295 evaporates the working fluid in the evaporator array 281 while the colder air in the inlet duct 293 condenses the working fluid in the condenser array 275. The heat captured from the warmer exhaust air by evaporation of the working fluid is transferred to the other side of the heat pipe system 271 where it pre-heats the colder inlet air before it arrives at the HVAC. Consequently, significantly less energy is required to heat the colder incoming air than would be required without the heat pipe system 271.
Significantly, no tilting mechanism is required to reverse flow of the liquid phase working fluid through the heat pipe system 271. This is contrary to some prior art heat pipe based heat recovery modules in which a complicated tilting system and more costly flexible ducts are needed to adjust the inclination of the conduits and use gravity to overcome resistance to flow of the liquid phase working fluid associated with counterflowing vapors in the conduits. Instead, whenever the condenser array 275 is in a relatively warmer environment and the evaporator array 281 is in a relatively cooler environment, the flow of the working fluid through the system 271 automatically reverses and the condenser sections function as evaporator sections while the evaporator sections functions as condenser sections. This is because the common vapor manifold 251 sufficiently reduces resistance to flow of liquid phase working fluid in the conduits 203 that natural liquid pumping forces produced by the thermal gradient are sufficient to produce flow of liquid between the condenser array 275 and evaporator array without requiring any gravitationally induced flow in the conduits. Accordingly, the conduits 203 can remain in the same horizontal orientation for operation in summer and winter.
Another embodiment of a heat pipe, generally designated 301, is illustrated in
The first leg 315′ of the first manifold 311′ is at one end of the conduits 303 of the first set 303a while the second leg 317′ of the first manifold is at the opposite end of the conduits of the second set 303b. The vapor passage 321′ extends across the gap 305 and between the legs 315′, 317′. The vapor passage 321′ is in fluid communication with the legs 315′, 317′ and allows vapor to flow through the manifold 311′ between the end of the conduits 303 of the first set 303a and the ends of the conduits of the second set 303b on the opposite side of the heat pipe 301 without flowing through any of the conduits of the first or second sets. The second vapor manifold 311″ is substantially identical to the first 311′ except that its legs 315″, 317″ are connected to the ends of the conduits 303 opposite the ends to which the legs 315′, 317′ of the first manifold 311′ are connected. The vapor passages 321′, 321″ of the manifolds 311′, 311″ are suitably substantially straight and criss-cross one another as they extend over the top of the gap 305.
The heat pipe 301 is suitable for use in a heat transfer system used to transfer heat between two different ducts of a ventilation system. Although the heat pipe 301 can be the only heat pipe in the ventilation system within the scope of the invention, it is possible to combine the heat pipe 301 with various other heat pipes to create a set of heat pipes that work together in the ventilation system. For example,
As illustrated schematically in
Without exchange of working fluid between the upstream and downstream heat pipes in a parallel flow situation, as illustrated in
On the other hand, in the heat pipes 301, 401 in the system 571 illustrated in
It is also noted that any of the vapor manifolds described for any of the embodiments described herein can optionally include a valve similar to the valve 161 illustrated
When introducing elements of the ring binder mechanisms herein, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” and variations thereof are intended to be inclusive and mean that there may be additional elements other than the listed elements. Moreover, the use of “forward” and “rearward” and variations of these terms, or the use of other directional and orientation terms, is made for convenience, but does not require any particular orientation of the components.
As various changes could be made in the above without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
Claims
1. A heat transfer system adapted for transferring heat between two different ducts in a ventilation system, the system comprising a heat pipe comprising,
- a plurality of conduits, each conduit including an evaporator section extending laterally from a first open end of the respective conduit, a condenser section extending laterally from a second open end of the respective conduit, and a liquid return section, the liquid return section for each conduit being connected to the evaporator section at a position away from the first open end and connected to the condenser section at a position away from the second open end so the evaporator and condenser section are in fluid communication with one another through the liquid return section for flow of liquid condensed in the condenser section to the evaporator section, the liquid return section of at least one conduit being distinct from the liquid return section of another of the conduits; and
- a common vapor manifold in fluid communication with and extending between the first and second open ends of each of said plurality of conduits so vapors produced in the evaporator sections can flow from the first open ends through the common vapor manifold to the second open ends without flowing through the conduits.
2. A heat transfer system as set forth in claim 1 wherein the conduits are substantially straight.
3. A heat transfer system as set forth in claim 1 wherein the heat pipe is a first heat pipe, the system further comprising at least one additional heat pipe, each additional heat pipe comprising:
- a plurality of conduits, each conduit including an evaporator section extending laterally from a first open end of the respective conduit, a condenser section extending laterally from a second open end of the respective conduit, and a liquid return section, the liquid return section for each conduit being connected to the evaporator section at a position away from the first open end and connected to the condenser section at a position away from the second open end so the evaporator and condenser section are in fluid communication with one another through the liquid return section for flow of liquid condensed in the condenser section to the evaporator section, the liquid return section of at least one conduit being distinct from the liquid return section of another of the conduits; and
- a common vapor manifold in fluid communication with and extending between the first and second open ends of each of said plurality of conduits so vapors produced in the evaporator sections can flow from the first open ends through the common vapor manifold to the second open ends without flowing through the conduits.
4. A heat transfer system as set forth in claim 3 wherein the heat pipes are arranged relative to one another to form an array of evaporator sections on one side of the system and an array of condenser sections on an opposite side of the system.
5. A heat transfer system as set forth in claim 4 further comprising a first set of fins on the evaporator sections and a second set of fins on the condenser sections.
6. A heat transfer system as set forth in claim 4 further comprising a frame supporting the heat pipes and fins, the frame being configured to extend from a first ventilation duct into a second ventilation duct different from the first duct.
7. A heat transfer system as set forth in claim 6 wherein when the evaporator sections of the heat pipes are in a relatively cooler environment and the condenser sections are in a relatively warmer environment, the evaporator sections can be operated as condenser sections and the condenser sections can be operated as evaporator sections without requiring any tilting of the heat pipes to reverse the flow of the liquid in the conduits.
8. A heat transfer system as set forth in claim 1 wherein said plurality of conduits are made of tubing no larger in diameter than ½ inch tubing.
9. A heat transfer system as set forth in claim 8 wherein the length of each of said plurality of conduits is in the range of about 100 to about 250 inches.
10. A heat transfer system as set forth in claim 1 wherein the heat pipe contains no more than a 35% charge of the working fluid.
11. A heat transfer system adapted for transferring heat between two different ducts in a ventilation system, the system comprising a heat pipe comprising,
- first and second sets of conduits, each set of conduits comprising a plurality of conduits extending between open ends and spaced vertically from one another, the conduits of the first set being in generally side-by-side relation with the conduits of the second set and spaced laterally from the conduits of the second set,
- a first vapor manifold comprising a leg at one end of the conduits of the first set, another leg at an opposite end of the conduits of the second set, and a vapor passage extending between and in fluid communication with the legs of the first manifold, wherein the vapor passage extends between the first and second sets of conduits so vapor can flow between the ends of the conduits of the first set and the opposite ends of the conduits of the second set through the first vapor manifold without flowing through any conduits of said first and second set of conduits, and
- a second vapor manifold comprising a leg at one end of the conduits of the second set, another leg at an opposite end of the conduits of the first set, and a vapor passage extending between and in fluid communication with the legs of the second manifold, wherein the vapor passage extends between the first and second sets of conduits so vapor can flow between the ends of the conduits of the first set and the opposite ends of the conduits of the second set through the second vapor manifold without flowing through any conduits of said first and second set of conduits.
12. A heat transfer system as set forth in claim 11 wherein the vapor passages of the first and second manifolds extend diagonally across a gap between the first and second sets of conduits and criss-cross one another.
13. A heat transfer system as set forth in claim 11 wherein the conduits of the first and second sets of conduits are substantially straight.
14. A heat transfer system as set forth in claim 11 wherein the vapor passages of the first and second manifolds extend across a top of a gap between the first and second sets of conduits.
15. A heat transfer system as set forth in claim 11 wherein said plurality of conduits made of tubing having a diameter no larger than ½ tubing.
16. A heat transfer system as set forth in claim 15 wherein the length of each of said plurality of conduits is in the range of about 100 to about 250 inches.
17. A heat transfer system as set forth in claim 11 wherein the heat pipe contains no more than a 35% charge of a phase changing working fluid.
18. A heat transfer system as set forth in claim 11 wherein the heat pipe is a first heat pipe, the system further comprising a second heat pipe comprising:
- first and second sets of conduits, each set of conduits comprising a plurality of conduits extending between open ends and spaced vertically from one another, the conduits of the first set being in generally side-by-side relation with the conduits of the second set and spaced laterally from the conduits of the second set by a gap,
- a first vapor manifold comprising a leg at one end of the conduits of the first set, another leg at an opposite end of the conduits of the second set, and a vapor passage extending between and in fluid communication with the legs of the first manifold, wherein the vapor passage extends across the gap between the first and second sets of conduits so vapor can flow between the ends of the conduits of the first set and the opposite ends of the conduits of the second set through the first vapor manifold without flowing through any conduits of said first and second set of conduits, and
- a second vapor manifold comprising a leg at one end of the conduits of the second set, another leg at an opposite end of the conduits of the first set, and a vapor passage extending between and in fluid communication with the legs of the second manifold, wherein the vapor passage extends across the gap between the first and second sets of conduits so vapor can flow between the ends of the conduits of the first set and the opposite ends of the conduits of the second set through the second vapor manifold without flowing through any conduits of said first and second set of conduits,
- wherein the second heat pipe is nested within the first heat pipe so the first and second sets of conduits for the second heat pipe are positioned in the gap between the first and second sets of conduits for the first heat pipe.
19. A heat transfer system as set forth in claim 18 further comprising a third heat pipe, the third heat pipe comprising;
- a plurality of conduits extending between opposite open ends; and
- a vapor manifold in fluid communication with and extending between the first and second open ends of each of said plurality of conduits so vapors can flow between the first and second open ends of the conduits through the vapor manifold without flowing through the conduits,
- wherein the conduits for the third heat pipe are positioned in the gap between the first and second sets of conduits for the second heat pipe.
20. A heat transfer system as set forth in claim 19 further comprising a fourth heat pipe, the fourth heat pipe comprising:
- a plurality of conduits extending between opposite open ends; and
- a vapor manifold in fluid communication with and extending between the first and second open ends of each of said plurality of conduits so vapors can flow between the first and second open ends of the conduits through the vapor manifold without flowing through the conduits,
- wherein the conduits for the fourth heat pipe are positioned in the gap between the first and second sets of conduits for the second heat pipe.
21. A heat transfer system as set forth in claim 11 wherein the heat pipe is supported by a frame mounted in a ventilation system so the conduits of the first and second set of conduits extend from a position within a first duct to a position within a second duct different from the first duct and the first set of conduits are upstream of the second set of conduits in each of the first and second ducts.
Type: Application
Filed: Sep 28, 2011
Publication Date: Jul 26, 2012
Inventors: Khanh Dinh (Gainsville, FL), Thang Dinh (Gainsville, FL)
Application Number: 13/247,714
International Classification: F28D 15/02 (20060101);