The field of the present disclosure relates to heat exchangers generally, and to enhancing isolation of a first fluid flowing through a heat exchanger from a second fluid flowing through the heat exchanger.
A common heat exchanger design permits heat to transfer from a first fluid stream to a second fluid stream while keeping the actual fluid in the first fluid stream separate from the actual fluid in the second fluid stream. In other words, the fluids do not mix. Keeping the two fluid streams separate permits using a source of heat or cold that is either dirtier or cleaner than a desired place or thing to heat. One example provided by U.S. Pat. No. 4,872,504 (“the '504 patent”) is where cooling is needed for a poultry confinement area. The air within the poultry confining area is dirtier than outside air due to dust, feathers, feed, and other particles suspended in the air. Circulating inside poultry air through one flow path and circulating outside air through the other flow path permits heat to be transferred from the inside air to the outside air without contaminating the outside air with particulate matter suspended in the inside air. Another example is a telecommunications shelter, where it is desirable to cool relatively clean air inside the shelter with relatively dirty outside air without transferring particulate matter to the inside air.
There are many constructions for such heat exchangers; an exemplary one is disclosed in the '504 patent as core 16, see FIG. 1 of the '504 patent, a portion of which is reproduced as
A typical housing, such as housing 12 of the '504 patent (FIG. 2), holds or retains the heat exchanger, such as core 16 of the '504 patent, and the housing defines fluid inlets and outlets, such as funneled portions 32 and connecting portions 34 of the '504 patent. Heat exchanger housings commonly include a heat exchanger pocket or sleeve, such as core-receiving chamber 14 of the '504 patent, with internal features for receiving a heat exchanger and separating the first fluid path through the heat exchanger from the second fluid path through the heat exchanger. For example, FIG. 2 of the '504 patent, reproduced as
The present inventors have recognized several disadvantages associated with existing heat exchangers and housings for retaining such heat exchangers such as: (1) for typical heat exchangers, there is no physical structure to assist separating the fluid flow paths through the heat exchanger without placing the heat exchanger in a housing; (2) there are commonly gaps between a heat exchanger and a heat exchanger pocket, sleeve, or chamber that typically require a gasket or other sealant to close, and require the associated time and expense of installing such sealant; (3) there may be gaps that cannot be seen, for example at a bottom of a sleeve or pocket, and thus the installer does not know to close such gaps with sealant; (4) some housings employ moving parts to effect a seal about a heat exchanger, but such moving parts can loosen, not seat properly, or wear with use, and thus not form a tight seal; (5) current heat exchanger and housing combinations commonly require relatively close dimensional tolerances between the heat exchanger and the pocket, sleeve, or chamber that receives the heat exchanger to form a satisfactory seal; and (6) such relatively close tolerances increase the manufacturing cost, and can make installation of a heat exchanger into a housing relatively difficult.
The present invention is directed to heat exchangers, and in particular to heat exchangers that provide substantially isolated fluid stream paths independent of interaction with a housing that holds the heat exchanger. One preferred arrangement includes a frame engaging a heat exchanger where the frame directs fluid flow into and out of the heat exchanger to substantially isolate a first fluid stream that enters and exits the heat exchanger from a second fluid stream that enters and exits the heat exchanger. In a preferred arrangement, the frame substantially isolates the first fluid stream that enters and exits the heat exchanger from the second fluid stream that enters and exits the heat exchanger without placing the heat exchanger and frame in a separate housing.
Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.
Preferred embodiments will now be described with reference to the drawings. While several preferred embodiments are described with reference to a frame assembly used with a heat exchanger, a practitioner in the art will realize from the description that the principles described are viable to other applications. The described embodiments, as well as other embodiments, have numerous applications where a heat exchanger provides heat transfer between two separate fluid streams without mixing the fluid from the two streams. Embodiments may be scaled and adapted to many applications. Embodiments preferably address one or more of the above described disadvantages, or may address other disadvantages, with currently available heat exchanger and housing arrangements for transferring heat from one fluid steam to another fluid stream.
Skirt 30 is preferably shaped and positioned on heat exchanger 10 to facilitate fan 50 directing first fluid stream 15 to a top side of heat exchanger 10 through a first flow path 55 through heat exchanger 10. Skirt 40 is preferably shaped and positioned on heat exchanger 10 to facilitate fan 50 drawing first fluid stream 15 from the top side of heat exchanger 10 through first flow path 55. Skirt 35 is preferably shaped and positioned on heat exchanger 10 to facilitate fan 60 directing second fluid stream 20 to a bottom side of heat exchanger 10 through a second flow path 65. Skirt 45 is preferably shaped and positioned on heat exchanger 10 to facilitate fan 60 drawing second fluid stream 20 from a bottom side of heat exchanger 10 through second flow path 65. “Top” and “bottom” are merely used to designate two opposing sides of heat exchanger 10 that are different from the sides of heat exchanger 10 that engage skirts 30, 35, 40, and 45; no orientation or positional information is meant to be associated with a top side or a bottom side of heat exchanger 10.
In one preferred arrangement illustrated in
For isolated loops, for example, isolated first fluid stream 15A and second fluid stream 20A, port skirts 30A and air mover pedestals 50A are assembled to the outer edge of the connecting struts 80A. The port skirts 30A/air mover pedestal 50A sub-assemblies are preferably a single piece component, but may include a multiple set of components. Preferably, such tying together of the columns 85A produces a preferred tension and compression to produce sealed and isolated fluid pathways, such as first fluid stream 15A and second fluid stream 20A, for example.
As the columns 85A and struts 80A are contacted with the heat transfer/fluid exchange polygon 10A a strip of gasket material or a bead of sealant is applied on the adjacent (facing) surfaces of the heat transfer/fluid exchange polygon 10A to promote a sealed and isolated fluid pathway construction. Preferred embodiments do not require an assembly fixture, or support, to perform assembly of the frame assembly components. Additionally, preferred embodiments include components, such as columns, struts, and port skirts, that are mechanically tied together, thus enabling embodiments to be moved to subsequent assembly steps even when a sealant or bonding material is not fully set or cured.
While the exemplary embodiment of
Preferably, substantial isolation of first fluid stream 15 from second fluid stream 20 is accomplished using four factors, singly or in any combination, assuming heat exchanger 10 and frame 5 are located in a fluid environment without fluid currents or fluid movement not attributed to fluid moving devices, such as fans 50 and 60. The first factor is drawing fluid for first fluid stream 15 from an area, direction, or both, where drawn fluid for first fluid stream 15 is not likely to have mixed with (1) fluid exiting second fluid stream 20 or (2) fluid drawn into second fluid stream 20. The second factor is directing fluid from first fluid stream 15 to an area, direction, or both, where directed fluid from first fluid stream 15 is not likely to mix with (1) fluid drawn into second fluid stream 20 or (2) fluid exiting second fluid stream 20. The third factor is drawing fluid for second fluid stream 20 from an area, direction, or both, where drawn fluid for second fluid stream 20 is not likely to have mixed with (1) fluid exiting first fluid stream 15 or (2) fluid drawn into first fluid stream 15. The fourth factor is directing fluid from second fluid stream 20 to an area, direction, or both, where directed fluid from second fluid stream 20 is not likely to mix with (1) fluid drawn into first fluid stream 15 or (2) fluid exiting first fluid stream 15. Additional examples include configuring skirts 30, 35, 40, and 45 to facilitate flow paths A and B illustrated in
Skirt 30 preferably includes a backing plate 70 to help prevent fluid in fluid stream 15 from mixing with fluid in fluid stream 20. Likewise, skirt 35 preferably includes a backing plate 75 to help prevent fluid in fluid stream 20 from mixing with fluid in fluid stream 15. Optionally, skirts 40 and 45 may include backing plates (for example, backing plates 76A as illustrated in
In the arrangement illustrated in
In alternate embodiments, a frame, such as frame 5, may be formed as one or two pieces that are stretched or wrapped around a heat exchanger, such as heat exchanger 10. For example, a frame may be a one piece construction made of silicone rubber and dimensioned to snugly fit around a heat exchanger to substantially isolate fluid entering and leaving a first fluid path formed by the frame from fluid entering and leaving a second fluid path formed by the frame.
Embodiments preferably provide a frame, whether including one or multiple components, that is easily assembled onto a heat transfer/fluid exchange unit. In certain embodiments easy frame assembly is accomplished at least partly because of the modular stack-up of the frame components around the heat transfer/fluid exchange unit. In preferred embodiments, a frame is easily sealed onto a heat transfer/fluid exchange unit, at least partly because of the open access to all sides of the heat transfer/fluid exchange unit when assembling a frame onto the heat transfer/fluid exchange unit. Preferred embodiments also provide quick assembly times for attaching a frame to a heat transfer/fluid exchange unit, at least partly because the frame features are assembled independently of and are functional independently of a housing designed to hold the heat transfer/fluid exchange unit.
In another preferred embodiment, a heat exchanger assembly includes a housing for retaining a heat exchanger unit. The housing is preferably configured for incorporation into a structure, such as a wall of a telecommunication shelter, that divides a first fluid containing area, for example, the inside of a telecommunication shelter, from a second fluid containing area, for example, the environment surrounding the telecommunication shelter.
A heat exchanger unit preferably includes a first side, a second side, a third side, a fourth side, a fifth side connecting between the first, second, third, and fourth sides, and a sixth side opposite the fifth side and connecting between the first, second, third, and fourth sides. A first fluid path and a second fluid path preferably run through the heat exchanger unit. Preferably, the first fluid path extends into one and out of one of the first, second, third, and fourth sides, and the second fluid path extends into one and out of one of the first, second, third, and fourth sides. Additionally, the heat exchanger unit is preferably configured to prevent fluid in the first fluid path from contacting fluid in the second fluid path while fluid traverses through the heat exchanger unit.
A frame is preferably connected to the heat exchanger unit for directing fluid into and out of the first and second fluid paths. For example, the frame preferably at least substantially covers the first, second, third, and fourth sides of the heat exchanger unit. A first fluid moving device, such as a fan or a pump, is preferably located in a portion of the frame to move fluid along the first fluid path and a second fluid moving device is preferably located in a portion of the frame to move fluid along the second fluid path.
Preferably, the combination of the heat exchanger unit, the frame, the first fluid moving device, and the second fluid moving device is configured to direct fluid into and out of the first fluid path and to direct fluid into and out of the second fluid path while substantially isolating fluid in the first fluid path from fluid in the second fluid path. In a preferred embodiment, such substantial isolation is accomplished while the heat exchanger unit is physically separate from the housing. Preferably, inserting or connecting the heat exchanger unit and frame combination to the housing provides additional isolation between fluid in the first fluid path and fluid in the second fluid path.
At step 610, a column 85 is attached to skirts 30 and 35 to connect skirts 30 and 35 to each other. Preferably, column 85 is attached to skirts 30 and 35 using adjustably tightening fasteners such as screws, bolts and nuts, or other suitable fastener to begin forming frame 5. At step 615, the beginning portion of frame 5 is engaged to heat exchanger 10, for example by sliding heat exchanger 10 into contact with skirts 30 and 35 and the column 85 holding skirts 30 and 35 together. Preferably, column 85 has a length L that is slightly less than the height H of heat exchanger 10. Making the length L of columns 85 slightly less than the height H of heat exchanger 10 preferably creates a snap fit between columns 85 and heat exchanger 10 or places heat exchanger 10 under sufficient compressive forces to assist retaining frame 5 on heat exchanger 10.
At step 620, another column 85 is attached to skirt 35. At step 625, skirt 40 is attached to skirt 35 via the column attached to skirt 35 at step 620. Another column is attached to skirt 40 and another column is attached to skirt 30 at step 630. At step 635, skirt 45 is attached to skirt 40 and to skirt 30 via the respective columns attached to skirts 40 and 30 at step 630.
At step 640, tension between skirts 30-45 is adjusted by selectively tightening or loosening the fasteners used to secure columns 85 to skirts 30-45. Tension is preferably adjusted to create a fluid tight, or substantially fluid tight, seal between frame 5 (which includes skirts 30-45 and the struts 80 and columns 85 holding skirts 30-45 together) and heat exchanger 10.
Optionally, a sealant material, such as a gasket or gasket strip made of natural rubber, neoprene, silicone, or other suitable material, or a flowable sealant such as silicone caulk may be placed between the struts 80, the columns 85, or both, and heat exchanger 10 as frame 5 is attached to heat exchanger 10. Preferably, the mechanical hold provided by fasteners engaging columns 85 to skirts 30-45 permits handling and movement of the assembled frame 5 and heat exchanger 10 prior to a flowable sealant drying or curing without causing disassembly of frame 5 or detachment of frame 5 from heat exchanger 10.
When connected to heat exchanger 710, frame assembly 705 preferably substantially isolates a first fluid stream 715 that enters and exits heat exchanger 710 from a second fluid stream 720 that enters and exits heat exchanger 710 without placing or associating heat exchanger 710 and frame 705 in or with the housing 725. In a preferred arrangement, frame 705 includes skirt 730, skirt 735, skirt 740, and skirt 745. Skirts 730 and 735 are preferably sized to accommodate a fluid moving device, such as a fan 750, pump, turbine, impeller, or other suitable device for moving a fluid.
Skirt 730 is preferably shaped and positioned on heat exchanger 710 to facilitate fan 750 directing first fluid stream 715 to a top side of heat exchanger 710 through a first flow path 755 through heat exchanger 710. Skirt 740 is preferably shaped and positioned on heat exchanger 710 to facilitate fan 750 drawing first fluid stream 715 from the top side of heat exchanger 710 through first flow path 755. Skirt 735 is preferably shaped and positioned on heat exchanger 710 to facilitate fan 760 directing second fluid stream 720 to a bottom side of heat exchanger 710 through a second flow path 765. Skirt 745 is preferably shaped and positioned on heat exchanger 710 to facilitate fan 760 drawing second fluid stream 720 from a bottom side of heat exchanger 710 through second flow path 765.
After assembling and engaging frame 705 onto heat exchanger 710, for example, as described above with respect to
Preferably, matching fluid inlet 800 and fluid exit 805 with skirts 740 and 730 and matching fluid inlet 810 and fluid exit 815 with skirts 745 and 735 helps further facilitate isolating the first fluid stream 715 from the second fluid stream 720. For example, housing 725 may be located in a wall or door of a telecommunication shelter. Fluid inlet 800 and fluid exit 805 may communicate with the interior air of the telecommunication shelter on one side of the wall or door, and fluid inlet 810 and fluid exit 815 may communicate with the exterior air surrounding the telecommunication shelter on the other side of the wall or door.
Optional gaskets 901 and 905 cooperate with first housing portion 990 to prevent, minimize, or lessen the chance of fluid flowing through skirt 945, heat exchanger 910 and skirt 935 from entering an interior space defined between first housing portion 990 and second housing portion 995. Optional gasket 900 cooperates with first housing portion 990 to prevent, minimize, or lessen the chance of fluid flowing through heat exchanger 910 and skirt 930 from entering the fluid-stream flowing through skirt 945, heat exchanger 910 and skirt 935.
In other embodiments, substantially identical gaskets 900, 901, and 905 are included between skirts 930, 935 and 945, respectively, and second housing portion 995.
In operation, when fluid is moved through heat exchanger 910 a first fluid flow path is defined through skirt 945, heat exchanger 910 and skirt 935. One or more optional gaskets 901 and 905 preferably prevent, minimize, or lessen the chance of fluid flowing through skirt 945, heat exchanger 910 and skirt 935 from entering an interior space defined between first housing portion 990 and second housing portion 995. A second fluid flow path is defined through opening 915 in first housing portion 990, the interior space defined between first housing portion 990 and second housing portion 995 and skirt 930. One or more optional gaskets 900 preferably prevent, minimize, or lessen the chance of fluid flowing through opening 915 in first housing portion 990, the interior space defined between first housing portion 990 and second housing portion 995 and skirt 930 from entering the first fluid flow path.
In other embodiments a single gasket may be used in place of gaskets 900, 901, and 905. Or, a flowable sealing material, such as silicone caulk, may be placed on portions of skirts 930, 935, 945 and heat exchanger 10 to create a seal between skirts 930, 935, 945 and first housing portion 990, second housing portion 995, or both.
It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. While certain preferred systems and methods have been shown and described, it will be apparent to one skilled in the art that modifications, alternatives and variations are possible without departing from the inventive concepts set forth herein. Therefore, the invention is intended to embrace all such modifications, alternatives and variations.
This application claims priority to U.S. provisional application No. 61/391,056 filed Oct. 7, 2010 and titled “Heat Exchanger Frame Apparatus And Method Of Assembly,” which is fully incorporated herein by reference.
Number | Date | Country | |
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61391056 | Oct 2010 | US |