HK1064439A - Heat exchange assembly - Google Patents

Description

Heat exchange assembly

Technical Field

The present invention relates to a heat exchange assembly and, more particularly, to a plate heat exchange assembly that can be optionally used as a liquid-to-vapor heat exchanger, a low flow internally cooled liquid desiccant absorber, a liquid desiccant regenerator, or an evaporative cooling fluid cooler.

Technical Field

Heating, ventilation and air conditioning (HVAC) systems regulate the environmental conditions inside buildings to make them comfortable. Such systems provide control of the indoor environment within a given space for occupants to create and maintain desired temperature, humidity and air circulation. In such systems, an important part is found to be the heat exchanger, which is used to transfer heat from one medium to another without mixing the media.

A heat exchanger includes a plurality of plates spaced apart from each other by partitions. The spaces between adjacent plates provide flow paths for the heat exchange fluid. Each plate comprises double-walled panels of metal or plastic, the walls being separated by partitions defining a plurality of internal passages therein. The baffles forming the internal channels provide fluid flow paths for the second heat exchange fluid. One example of the use and structural and operational details of such heat exchangers is disclosed in U.S. patent nos. 5,638,900 and 6,079,481, which are incorporated herein by reference.

U.S. patent 5,469,915 discloses a heat exchanger comprising a plurality of flat plates (also referred to as "panels") arranged in a spaced apart relationship. Each of the flat plates includes a plurality of tubular members arranged along a plane and sandwiched between a pair of plastic films laminated on the flat plates and opened at both ends. A manifold is mounted at the open end of the plate. Heat exchange fluid is supplied to the plates from one manifold and exits the plates through the other manifold. In one embodiment, each manifold has a plurality of holes into which the ends of the plates are inserted and sealed. In another embodiment, each manifold is made up of two pieces, each with a half-round grooved piece that matches the profile of the tubular piece. The ends of the flat tubular member are clamped between the two halves of the manifold so that the ends of the flat tubular member are fully received within the manifold and the flat form an airtight assembly. Regardless of which of these two embodiments of manifolds, a heat exchanger assembly comprising two or more plates can be made by stacking the manifolds and connecting the manifolds together.

U.S. patent 4,898,153 discloses a heat exchanger constructed of double walled plates having a plurality of internal flow channels. It is also disclosed that the ends of the plates are joined to an end piece, the end piece being provided with grooves to rotate the fluid flow path through the plates by 180 °, and the outlet and inlet pieces being connected to the end piece.

In HVAC systems, a dehumidifier may be used to extract moisture from process air to produce relatively dry air. The treated air is typically dried by cooling and/or dehumidification. In the dehumidification process, air is typically passed through an apparatus known as an absorber, which typically includes a cavity containing an absorbing substance such as silica gel or calcium chloride. The absorber, referred to herein as a fluid dry absorber, uses a liquid desiccant or desiccant to remove water vapor from the process air. Examples of such fluid dry absorbers and other details of their operation are disclosed in U.S. patent 5,351,497, which is incorporated herein by reference.

Fluid dry absorbers typically include a porous bed of catalyst filled with a liquid desiccant. As the desiccant flows through and permeates the porous bed, the desiccant comes into contact with the aqueous air flowing therethrough. By definition, desiccants have a strong affinity for water, absorbing or extracting moisture from process air.

During the drying process, heat is released as the water vapor condenses and mixes with the desiccant. The total heat generated is generally equal to the sum of the latent heat of condensation of the water and the heat generated by mixing the desiccant with the water. In a typical absorber, the heat of mixing will be about an order of magnitude less than the latent heat of condensation. The heat released during drying raises the temperature of the air and desiccant. The air in the absorber has approximately the same enthalpy as it entered. For example, air enters the absorber at 80 ° F, 50% relative humidity (31.3 BTU/1b enthalpy), and exits at 97 ° F, 20% relative humidity (31.5 BTU/1b enthalpy). In this configuration, the absorber serves only as a dehumidifier.

The absorber may be included in an air cooling system. By cooling the desiccant and process air through a heat exchanger using a cooling liquid or refrigerant, the process air exits the absorber at a lower enthalpy and relative humidity than it entered, thereby producing the desired net cooling effect. Absorbers using such cooling assemblies often exhibit increased drying capacity and efficiency over absorbers that do not use such cooling assemblies. However, existing internal refrigeration absorbers are generally more difficult and costly to manufacture. In addition, such absorbers often encounter difficulties in separating the respective heat exchange fluid streams from the liquid desiccant due to the common leakage problems.

It would therefore be a significant advance in the art of heat exchange to provide a heat exchange assembly that effectively maintains the respective heat exchange fluids and media separate from one another and is efficiently manufactured from corrosion resistant materials in a structure that can be used in a variety of heat exchange systems, including but not limited to liquid-to-air heat exchangers, internal refrigeration liquid desiccant absorbers, and evaporative cooling fluid coolers.

Disclosure of Invention

In summary, the present invention is directed to a heat exchange assembly comprising:

a plurality of spaced apart plates, each plate including a plurality of channels extending internally therefrom from a first end to a second end for directing a flow of heat exchange fluid within the first plate;

a plurality of first end pieces and a plurality of second end pieces equal in number to the number of plates, each first end piece and second end piece comprising a recessed area adapted to be movably coupled to a first end and a second end of a plate, respectively, and adapted to be attached to adjacent first and second end pieces in a stacked formation, each first end piece and second end piece further comprising at least one cavity to enable a heat exchange fluid to enter and exit the plates or to rotate the fluid 180 ° within the plates to create a flow path between an entry point and an exit point of the fluid; and

at least two fluid conduits pass through the plurality of first and second end pieces of the stack to provide a first fluid path between the parallel fluid entry points of adjacent plates and the fluid supply inlet and a second fluid path between the parallel fluid exit points of adjacent plates and the fluid discharge outlet, whereby the heat exchange fluid travels along parallel channels through each plate.

In another aspect of the present invention, there is provided another heat exchange assembly including:

a plurality of spaced apart plates, each plate including a plurality of channels extending internally therefrom from a first end to a second end for directing a flow of heat exchange fluid within the first plate;

a plurality of end members equal in number to the number of plates, each end member comprising a recessed area adapted to be movably coupled to a first end and a second end of a plate and adapted to be attached to an adjacent end member in a stacked configuration, each end member further comprising at least one cavity to allow a heat exchange fluid to enter and exit the plate or to rotate the fluid 180 ° within the plate to create a flow path between an entry point and an exit point of the fluid;

a fluid rotation device disposed at the first end of the plate for rotating a fluid stream entering the plate; and

a fluid supply inlet and a fluid exhaust outlet, each inlet and outlet being connected to an attachment to the end piece such that the heat exchange fluid travels along parallel paths through the respective plates.

Drawings

In the following drawings, in which like reference numerals refer to like parts, embodiments of the present invention are illustrated in the drawings and are not intended to limit the invention, which is encompassed by the claims forming a part of the present application.

FIG. 1 is a perspective view of one embodiment of a heat exchange assembly according to the present invention;

FIG. 2 is a partially exploded assembly view of the heat exchange assembly of FIG. 1;

FIG. 3 is a front view of a top fluid manifold, a bottom fluid manifold and a plate mounted therebetween according to the present invention;

FIG. 4 is a partial cross-sectional view of a heat exchange assembly according to the present invention showing internal heat exchange fluid flow passages through the manifold and the plates;

FIG. 5A is a perspective view of the top end piece of the heat exchange assembly according to the present invention;

FIG. 5B is a perspective view of the bottom end piece of the heat exchange assembly according to the present invention;

FIG. 5C is a detailed cross-sectional view of a stop block of a modified top or bottom end piece according to a second embodiment of the present invention;

FIG. 6 is a front view of a modified plate and end piece according to a third embodiment of the present invention;

FIG. 7 is a perspective view of a heat exchange assembly according to a fourth embodiment of the present invention;

FIG. 8 is a front view of the top fluid manifold, the bottom fluid manifold and the flat plate mounted therebetween of the heat exchange assembly of FIG. 7, in accordance with the present invention;

FIG. 9A is a perspective view of the top end piece of the heat exchange assembly of FIG. 7 according to the present invention;

FIG. 9B is a perspective view of the top end piece of a heat exchange assembly having a desiccant supply network with an exemplary desiccant distribution slot in accordance with the present invention;

FIG. 9C is a top end member elevational view with a purge conduit according to a fifth embodiment of the invention;

FIG. 9D is a perspective view of the bottom end piece of the heat exchange assembly of FIG. 7 in accordance with the present invention;

FIG. 10A is a perspective view of the top end piece of the heat exchange assembly of FIG. 7 showing a pattern of adhesive beads for mounting on the ends of the plate in accordance with the present invention;

FIG. 10B is a perspective view of the bottom end piece of the heat exchange assembly of FIG. 7 showing a pattern of adhesive beads for mounting on the ends of the plate in accordance with the present invention;

FIG. 11A is a front view of the top end piece of the heat exchange assembly of FIG. 7 showing a pattern of adhesive beads for mounting on the ends of the plate in accordance with the present invention; for accessing an adjacent top end piece;

FIG. 11B is a front view of the bottom end piece of the heat exchange assembly of FIG. 7 showing a pattern of adhesive beads for mounting on the ends of the plate in accordance with the present invention; for accessing an adjacent bottom end piece;

FIG. 12 is a perspective view of a modified plate and end piece according to a sixth embodiment of the invention;

FIG. 13 is a perspective view of a heat exchange assembly according to a variation of the seventh embodiment of the present invention; and

fig. 14 is an elevation view of modified top and bottom end pieces according to another embodiment of the invention.

Detailed Description

The present invention is generally directed to a heat exchange assembly constructed in a manner for efficiently transferring thermal energy between an isolated first fluid flowing through a plurality of spaced-apart plates, a second and/or third fluid passing through spaces between adjacent plates, via fluid manifolds connected at each end of the plurality of plates. The heat exchange assembly is made of a lightweight material and is adapted to provide reliable and efficient heat transfer. Alternatively, the heat exchange assembly may be made to operate as an internal chilled liquid desiccant absorber to regulate the water content of the fluid flowing over the liquid desiccant surface; or as a liquid desiccant regenerator adapted to expel moisture within the liquid desiccant into the airflow passing over the surface of the liquid desiccant; or as an evaporative cooling fluid cooler to remove heat from the fluid flowing inside the plate.

In contrast to the heat exchange assembly described in U.S. patent 5,469,915, the ends of the plates need not be inserted into openings in the manifold, but a manifold member is attached to each end of the plates. In contrast to the solar heat exchanger described in U.S. patent 4,898,153, the manifold members also serve as spacers to provide suitable spacing between the plates.

The heat exchange assembly generally provides a heat exchange fluid that flows through a plurality of plates, each plate having first and second ends with one or more internal passages extending therebetween. An end piece is in fluid communication with each end of the plate for directing fluid flow within the channels in the plate. The flat plate separates the heat transfer fluid from the external fluid medium while maintaining a heat exchange relationship therebetween. The flat plates in which the channels are formed are preferably made of profiled plates or the like, corrugated plates, tube plates, punched plates, thermoformed plates, etc., each of which is readily made of a rigid corrosion resistant material such as a plastic polymer material, a corrosion resistant metal, etc.

As used herein, the term "profile plate" refers to an assembly made as a double wall plate structure in which the double walls are spaced along the entire length of the plate by a set of preferably uniformly spaced ribs or webs. The fins form a plurality of channels as referred to herein. One construction of profile board is disclosed in U.S. patent 4,898,153, the contents of which are incorporated herein by reference.

As used herein, the term "corrugated board" refers to an assembly generally comprising three layers of thin boards, two layers being substantially flat and forming the outer surface of the board, and the third layer being non-flat. The third layer is typically folded, molded, stamped or otherwise formed to maintain the outer layers of the plates parallel to each other while interposing them between the first and second layers to form flow channels therebetween through the length of the plates. The three sheets may be glued, coupled, welded, fastened or fused together at their points of contact to form a more rigid structure.

As used herein, the term "tubesheet" refers to an assembly made from a plurality of open-ended tubular members, each tubular member having a circular cross-section, joined longitudinally therealong to form a substantially flat-sheet like structure.

Referring to the drawings and in particular to FIG. 1, a heat exchange assembly 10 of the present invention is shown. The heat exchange module 10 generally includes a top fluid manifold 12, a bottom fluid manifold 14, a plurality of parallel aligned and spaced apart hollow rectangular plates 16, and a pair of profile plates 18 to seal the ends of the module. The top fluid manifold 12 is comprised of a plurality of top end pieces 26 with adjacently engaged side-by-side abutting assemblies. The bottom fluid manifold 14 is comprised of a plurality of bottom end pieces 28, which are arranged in a similar manner as the previously described top end pieces 26. Each plate 16 is connected at one end 44 to the top end piece 26 and at the other end 50 to the bottom end piece 28 to form a plate/end piece assembly. In this configuration, each plate/end piece assembly is arranged in a stacked manner and securely engaged with one another. Each end piece 28 includes a through-hole that forms a respective fluid tight conduit and reservoir. The components of the assembly 10 may be secured by methods including, but not limited to, gluing, welding, brazing, coupling, fastening, clamping, etc. to form the heat exchange assembly 10. The assembly 10 also includes an inlet piece 22 and an outlet piece 24 fluidly connected to the top fluid manifold 12.

The assembly 10 is adapted to receive an internal heat exchange fluid through the inlet piece 22. A heat exchange fluid is circulated through the assembly 10 to perform a heat exchange operation as will be described in detail below. In combination, the top and bottom fluid manifolds 12 and 14 and the plate 16 serve to maintain a continuous flow path for the internal heat exchange fluid through the module 10. The circulating internal heat exchange fluid is then discharged from the assembly 10 through the outlet member 24. It is noted that the assembly 10 may be modified to provide multiple inlet and/or outlet members and to provide such inlet or outlet members at other locations as desired.

The spaced plates 16 define a plurality of voids 20 to allow the passage or quiescence of an external solid or fluid medium. In the latter case, the fluid medium enters the void 20 of the assembly 10 at one end and exits at the opposite end. The gaps 20 between adjacent plates 16 are preferably evenly spaced while being relatively close to each other to promote efficient and compact heat exchange operation. The plates 16 of the assembly 10 are arranged in a generally vertical orientation. However, it should be understood that the plate 16 may be disposed in other suitable orientations depending on the application or needs.

The internal heat exchange fluid flowing within the channels may be gaseous or liquid. The external medium may be a solid, liquid or gas. For example, the solid may be a device capable of exchanging heat with an internal heat exchange fluid. The present heat exchange assembly may be used, for example, in a refrigerated storage system, an evaporative fluid cooler, a liquid desiccant absorber, a liquid desiccant regenerator, a gas condenser, a liquid boiler, a liquid-to-gas heat exchanger, or any device in which heat exchange between discrete media is desired.

Referring to fig. 2 and 3, the top fluid manifold 12 and the bottom fluid manifold 14 are configured in combination to securely maintain the plurality of plates 16 in a spaced relationship, facilitate fluid flow into and out of the plurality of plates 16, and establish fluid flow channels (e.g., serpentine fluid flow channels) within each plate 16 as will be described in greater detail below. In particular, the manifolds 12 and 14 have structural features that align with each plate 16 to facilitate the desired fluid flow within the plate 16 and around the plate 16. The fluid flow channels (e.g., serpentine fluid flow channels) allow the internal heat exchange fluid to pass through the respective plates 16 multiple times, thereby maximizing the efficiency of the heat exchange operation between the associated media. Profile plates 18 are attached to the ends of the assembly 10 to seal or enclose the internal heat exchange fluid within each internal cavity and provide structural strength and rigidity to the assembly 10.

The top fluid manifold 12 includes an end wall 30 and a pair of side walls 32 extending longitudinally along the edges of the end wall 30. The top fluid manifold 12, which secures the plurality of plates 16 together in the operative position, defines an inlet conduit 34 and an outlet conduit 36, each of which extends longitudinally inwardly thereof. An inlet conduit 34 is in fluid communication with the inlet piece 22 and conveys the internal heat exchange fluid longitudinally of the assembly 10 to each plate 16. The internal heat exchange fluid flows along the channels in each plate 16 into and out of the bottom fluid manifold 14 until it reaches the outlet conduit 36 and is discharged through the outlet member 24. The top fluid manifold 12 on each plate 16 also includes one or more spin chambers 40 and recessed areas 42 aligned with the plates 16. The rotating chamber 40 is used to direct fluid out of the plate 16 and back into the plate 16 to form a continuous fluid flow, as will be described in more detail below. The recessed area 42 is adapted to receive and securely retain an end 44 of the respective plate 16 to form a fluid-tight, sealing engagement therebetween.

Alternatively, the top fluid manifold 12 may include an optional bypass conduit 38 extending longitudinally through a spin chamber 40 associated with each plate 16. The bypass conduit 38 provides open fluid communication between adjacent rotating chambers 40. If one or more of the channels 54 in the plate 16 becomes blocked or clogged, the bypass conduit 38 bypasses the internal heat exchange fluid through the plate 16. In normal operation, there is little to no fluid exchange at the articulated spinner chamber 40 between the plates 16. However, when one or more of the passages 54 in a plate 16 is blocked or obstructed, the corresponding fluid may bypass the blockage via the bypass conduit 38 and flow into an adjacent, unblocked plate 16.

The bottom fluid manifold 14 is similar in structure to the top fluid manifold 12. The bottom fluid manifold 14 includes an end wall 46 and a pair of side walls 48 extending longitudinally along the edges of the end wall 46. The bottom fluid manifold 14 on each plate also includes one or more spin chambers 40 and recessed areas 42 aligned with each plate. The rotating chamber 40 is used to direct fluid out of the plate 16 and back into the plate 16 to form a continuous fluid flow. The recessed area 42 is adapted to receive and securely retain an end 50 of the corresponding plate 16 to form a fluid-tight seal. The bottom fluid manifold 14 optionally includes one or more bypass conduits 38, each bypass conduit 38 being aligned with a separate plate 16. The arrangement of the plates 16 and the manifold securing the plates enables the bypass conduit 38 to extend along the length of the module 10 and provide fluid communication between the rotating chambers 40 associated with each of the plates longitudinally aligned with one another within the module 10. The function of the bypass conduit 38 in the bottom fluid manifold 14 is the same as that described above in the top fluid manifold 12.

Referring to fig. 4, the flow paths of the internal heat exchange fluid through the top and bottom fluid manifolds 12 and 14, respectively, and the plate 16 are shown in detail. The plate 16 includes a plurality of spaced walls 52 defining a plurality of open-ended channels 54 for conveying fluid. The top and bottom fluid manifolds 12 and 14, respectively, include one or more baffles 56 to close the respective conduits, the rotating chambers, and the channels connecting the respective plates 16 to facilitate the orderly flow of fluids. Fluid tends to flow in the direction from a high pressure region (e.g., inlet conduit 34) to a low pressure region (e.g., outlet conduit 36). The internal heat exchange fluid first enters the inlet conduit 34 through the inlet piece 22 and then flows in the direction of arrow "a" through the at least one channel 54 to the bottom fluid manifold 14. The fluid enters the rotating chamber 40, which rotating chamber 40 directs the fluid flow 180 ° in the direction of arrow "B" toward the top fluid manifold 12. The fluid is rotated more than twice before entering the outlet conduit 36 and exiting the assembly 10 through the outlet member 24. The internal heat exchange fluid passes in parallel through each plate 16 of the assembly 10. In operation, the external fluid medium preferably flows in the opposite direction to the total flow of heat exchange fluid in the plate 16.

As previously noted, the manifolds 12 and 14 form a rotating chamber 40 that directs the flow of fluid back and forth across the plate 16. The number of spin chambers 40 provided may vary depending on the needs and requirements of the assembly 10.

In a cooling operation, the internal heat exchange fluid is first cooled by a cooling system (not shown) to a temperature below that of the external fluid medium (e.g., room air). The cooled internal heat exchange fluid then flows into the heat exchange assembly 10 through the inlet piece 22 (see fig. 2), into the inlet conduit 34 and into the plate 16. The internal heat exchange fluid travels along the serpentine flow path, rotating 180 ° within the rotating chamber 40. Since the internal heat exchange fluid is cooler than the external fluid medium as it passes through the spaces 20 between adjacent plates 16, heat is transferred from the external fluid medium to the internal heat exchange fluid through the walls of the plates 16. The external fluid medium, which is drawn up in thermal energy, exits the heat exchange assembly 10 and returns to the receiving area (e.g., room). The internal heat exchange fluid passes through the plates 16 into the outlet conduit 36 and exits the heat exchange assembly 10 through the outlet member 24. The operation of the heat exchange assembly 10 during heating is similar to, but significantly altered from, the heat transfer relationship between the internal heat exchange fluid and the external fluid medium.

Referring to fig. 5A and 5B, the top and bottom end-pieces 26 and 28, respectively, are shown in more detail, as described in connection with fig. 1. The top end piece 26 includes a spin chamber 40, an inlet throughbore 58 forming a portion of the inlet conduit 34 of the top fluid manifold 12, an outlet throughbore 60 forming a portion of the outlet conduit 34 of the top fluid manifold 12, and two bypass throughbores 62, the bypass throughbores 62 forming a portion of the bypass conduit 38. The top end piece 26 includes a recessed area 42 adapted to receive and securely retain an end 44 of a corresponding plate 16 to maintain a fluid-tight fit therebetween. The edges of the plate 16 abut the tips of the baffles 56 to ensure that the channels 54 are separated for balanced fluid flow.

The bottom end piece 28 is shown explicitly in fig. 5B. The bottom end-piece 28 includes two spin chambers 40 and four bypass throughbores 62, each forming a portion of a respective bypass conduit 38. It will be appreciated that the bottom end piece 28 can be formed to include inlet and/or outlet through-holes 58, 60 when it is desired to provide the inlet and/or outlet pieces 22, 24, respectively, on the bottom fluid manifold 14.

The bottom end-piece 28 also includes a recessed area 42 adapted to receive and securely retain an end 50 of a corresponding plate 16 to maintain a fluid-tight fit therebetween. The edges of the plate 16 abut the tips of the baffles 56 to ensure separation of the channels 54 to maintain smooth fluid flow. It is noted that the plate 16 may be securely attached within the recessed areas 42 of the end members 26 and 28 by methods including, but not limited to, gluing, welding, fusing, bonding, fastening, snapping, and the like.

The number of spin chambers 40 in the end pieces 26 and 28 can vary depending on the needs of the assembly 10. In this embodiment, it is noted that the internal heat exchange fluid makes three 180 ° turns through the plates 16 along its path (as shown in fig. 4). This configuration is referred to as a four-way heat exchanger, meaning that the serpentine fluid flow path along which the internal heat exchange fluid travels comprises four straight sections. The rotating chambers 40 are separated from each other and from the inlet and outlet through-holes 58 and 60, respectively, by partitions 56, as described herein. The baffles prevent the internal heat exchange fluid from surrounding the plates 16. Preferably, each rotating chamber 40 has a depth equal to or greater than the thickness of the plate 16 or the channel 54 in the plate 16 to maximize unimpeded flow into or out of the respective plate 16.

Optionally, bypass throughbores 62 are included in end members 26 and 28, respectively, and are not critical to the operation of assembly 10. The bypass throughbore 62 forms the bypass conduit 38 within the assembly 10. As described above, the bypass conduit 38 serves to enable the internal heat exchange fluid flowing into the plate 16 to flow into the parallel plates if the internal heat exchange fluid encounters one or more blocked channels 54.

The overall thickness of each individual end piece 26 or 28 generally includes the thickness of the attached flat plate 16 and the width of the desired spacing between adjacent flat plates 16. Preferably, the depth of the recessed areas 42 in the top and bottom end pieces 26 and 28 is equal to the thickness of the plate 16. Note, however, that the depth of the recessed region may vary relative to the thickness of the plate 16 and may be less than the thickness of the plate. In the latter case, the opposite side of end piece 26 or 28 may also include a corresponding recessed area for receiving the extended exposed portion of plate 16. Similarly, the depth of the recessed region 42 may be greater than the thickness of the plate 16. Thus, in contrast to the flat plate 16 having filled recessed areas 42, the opposite side of the end piece 26 or 28 includes a raised area adapted to fit snugly into the recessed area 42 of the adjacent end piece 26 or 28, respectively. In this manner, the flat plate 16 of the adjacent end member 26 or 28 is securely held therebetween.

Referring to FIG. 5C, in a second embodiment of the invention, the baffle 56 in the top and bottom end-pieces 26 and 28 may be modified to include bypass channels 64. Bypass channel 64 fluidly connects the spin chamber, reservoir chamber and conduit to retain/correct or purge trapped air or gas while filling assembly 10 with internal heat exchange fluid, thereby facilitating venting of assembly 10. Sizing the bypass channels 64 in this manner allows the flow rate through the plate 16 to be substantially unaffected by the bypass channels 64, preferably less than 3% of the total flow rate of the internal heat exchange fluid.

Referring to fig. 6, a heat exchange assembly 70 according to a third embodiment of the present invention is shown. The heat exchange assembly 70 includes the top fluid manifold 12 and a plate 72. The plate 72 is connected to the top fluid manifold 12 in the same manner as described above. The plate 72 includes a plurality of walls 52 forming a plurality of channels 54 and a rotating chamber 74 provided at an opposite end 78 thereof, the channels 54 being open at one end 76 thereof. In this configuration, a rotating chamber 74 is built into the plate 72 and rotates the fluid flow therein. It is noted that the plate 72 may be modified so that the rotating chamber 74 is located at one end thereof, as disclosed in U.S. patent 5,638,900, which is incorporated herein by reference.

Referring to fig. 7, a heat exchange assembly 80 in a fourth embodiment of the present invention is shown. The heat exchange assembly 80 is substantially similar to the heat exchange assembly 10 described above. In this embodiment, the heat exchange assembly 80 includes a top fluid manifold 92 and a bottom fluid manifold 94 that combine to form a liquid desiccant distribution and collection system. The liquid desiccant delivery system is adapted to provide a thin layer of liquid desiccant flow on the surface of the plate 16, as described below. The heat exchange assembly 80 also includes a desiccant inlet 82 and a desiccant outlet 84 to supply and discharge, respectively, liquid desiccant.

Referring to fig. 8, the top fluid manifold 92 includes a liquid desiccant supply tube 86, the liquid desiccant supply tube 86 extending longitudinally of the assembly 80 and serving to transfer liquid desiccant from the inlet 82 to the plate 16. The liquid desiccant supply line 86 branches into a plurality of supply lines 88, each supply line 88 carrying liquid desiccant into the interstices 20 between adjacent plates 16. The liquid desiccant is then distributed over the surface of the adjacent plate 16 where it flows down to the bottom fluid manifold 94. Bottom fluid manifold 94 includes sidewalls 100 extending along each side of bottom fluid manifold 94. The sidewall 100 serves to retain liquid desiccant that flows down the surface of the plate 16 and prevents the liquid desiccant from being entrained in the external fluid medium flowing through the gap 20. The collected liquid desiccant flows to one side of the manifold 94 where it passes through drain tubes 102 provided between the plates 16 into a drain conduit 104. The drain conduit 104 extends longitudinally along the assembly 80. The liquid desiccant is finally discharged from the drain conduit 104 through the desiccant outlet 84. The discharged liquid desiccant is then reprocessed or sent to a liquid desiccant regenerator (not shown).

Referring to fig. 9A, top fluid manifold 92 is assembled from a plurality of top end pieces 96, each top end piece 96 being connected to an end 44 of plate 16. The top end piece 96 is secured to an adjacent top end piece to form the top fluid manifold 92. The top end piece 96 includes a supply through hole 106 forming part of the supply conduit 86, a supply line 88 and a distribution screen 108 having a plurality of distribution slots 110, the distribution slots 110 being provided on both sides of the distribution screen 108 and extending from the supply line 88. Preferably, the distribution grooves 110 are relatively staggered between the front and rear sides of the grooves 110. The offset of the grooves 110 prevents the liquid desiccant from flowing through the gaps 20 between adjacent plates 16.

Top end piece 96 also includes a recessed area 42 for receiving and securely holding end 44 of plate 16. When the plate 16 is attached to the top end piece 96, the supply line 88 and distribution groove 110 are closed. When the assembly 80 is constructed, the surfaces of adjacent plates 16 on the other side of the top end piece 96 abut oppositely and enclose the supply line 88 and distribution groove 110. In operation, liquid desiccant flows from the conduit 86 into the supply line 88 and into the distribution trough 110 where it is poured onto the nearest surface of the adjacent plate 16. Alternatively, a wick (not shown) may be used on the exposed surface of the plate below the distribution grooves 110 to promote uniform diffusion.

The distribution slots 110 effectively deliver the liquid desiccant onto the upper surface of the plate 16. The distribution slots 110 may be used to feed approximately the same flow rate of liquid desiccant at each distribution outlet. Because the liquid pressure of the liquid desiccant in the supply line 88 can be varied in its longitudinal direction, the distribution grooves will effectively maintain nearly equal flow rates as long as the pressure drop is large compared to the pressure change in the supply line 88.

For a given flow rate of the liquid desiccant, the pressure drop within the distribution groove 110 increases as the length of the distribution groove 110 becomes longer or the cross-sectional diameter decreases. Because the diameter of the distribution groove 110 is reduced, dirt, debris or sediment is more likely to clog the distribution groove 110. Alternatively, as the distribution groove 110 becomes longer, the distribution mesh 108 is correspondingly longer. This may undesirably increase the height of the corresponding heat exchange assembly. Referring to fig. 9B, the pressure drop across the distribution groove 110 may be increased by non-linearly extending the groove without extending the distribution mesh 108, as shown by grooves 110B, 110C, and 110D, respectively.

In an alternative embodiment, the distribution network 108 may be made of a porous material, such as open cell foam, to supply the liquid desiccant. The liquid desiccant flows from the supply line 88 through the pores and permeates the material. The liquid desiccant flows out of the lower end of the porous material onto the surface of the plate 16.

During operation of the heat exchange assembly, air bubbles may be present in the liquid desiccant in the supply line 88. The bubbles eventually pass through the distribution slots 110 where they collapse and create numerous small droplets of desiccant, which may be undesirably entrained within the external fluid medium passing through the gap 20. The entrained liquid desiccant is carried by the external fluid medium and lands on the external surface (e.g., on an air conduit). Because most liquid desiccants are corrosive, entrained liquid desiccants can cause serious maintenance problems.

Referring to fig. 9C, top end piece 134 includes a purge through hole 66 to form a purge chamber (not shown) extending longitudinally along the completed heat exchange assembly. The purge through hole 66 is located at the opposite end of the desiccant supply through hole 106 from the supply line 88. In heat exchange assemblies using the top end piece 134, the liquid desiccant flows into the distribution slots 110 and into the purge chamber through the purge through holes 66. Due to its low density, bubbles present in the liquid desiccant flow will travel with the liquid desiccant in the supply line 106 and be carried directly into the purge chamber. The liquid desiccant and air bubbles exit the purge chamber through corresponding purge elements (not shown).

Referring to fig. 9D, the bottom fluid manifold 94 is assembled from a plurality of bottom end pieces 98, each bottom end piece 98 being connected to an end of the plate 16 opposite the top end piece 96. End 50 of plate 16 fits securely within and connects to recessed area 42 to ensure abutment against the top of spacer 56. A support web 114 is provided to provide structural strength to the respective side wall 100. Preferably, the thickness of the support screen 114 is less than the overall thickness of the bottom end piece 98, and more preferably, is half the thickness of the bottom end piece 98, to form the drain pipe 102. The bottom end-piece 98 also includes a desiccant conduit through-hole 116 that forms a portion of the desiccant supply tube 86 of the assembly 80. Optionally, the recessed region 42 may include a beveled edge portion 112 to funnel the liquid desiccant toward the drain 102. The beveled edge portion 112 is preferably angled approximately 5 to 15 from horizontal to facilitate the flow of desiccant into the drain 102. Optionally, the sidewall 100 proximate the upper end of the beveled edge portion 112 of the recessed area 42 may also include a leading edge dam 118, and the sidewall proximate the lower end of the beveled edge portion 112 of the recessed area 42 may also include a trailing edge dam 120. Leading and trailing edge dams 118 and 120, respectively, are adapted to cooperate to shield liquid desiccant flowing along the beveled edge portion 112 from the external fluid medium passing between the voids 20 to minimize entrainment of liquid desiccant within the external fluid medium. It is noted that the respective leading and trailing edge dams 118 and 120 and beveled edge portion 112 are each optionally employed as the external fluid medium passes at a relatively high velocity.

Top and bottom end pieces 96 and 98, respectively, are joined in the configuration shown in fig. 8 to form a plate/end piece assembly in a manner similar to the method of assembly 10 described above to form assembly 80. The plate/end piece assemblies are then stacked on top of each other and attached using methods including, but not limited to, gluing, fusing, coupling, brazing, welding, fastening, and the like. Preferably, an adhesive is used to bond the plastic components. The connection may be made by applying a bead of adhesive to the surface of the plate/end piece assembly. Referring to fig. 10A and 10B, an embodiment of a bead of adhesive 122 is shown applied to recessed areas 42 of end pieces 96 and 98, respectively, to attach ends 44 and 50, respectively, of plate 16. Referring to fig. 11A and 11B, another bead of adhesive 122 is shown applied to the surfaces of end pieces 96 and 98, respectively, to join plate 16, adjacent plates, and the stacked plate/end piece assembly to form heat exchange assembly 80. Adjacent top and bottom end members are joined together to maintain structural integrity of the assembly 80 and form respective top and bottom fluid manifolds, respective fluid-tight passages and conduits for passage of the liquid desiccant and internal heat exchange fluid therethrough.

Referring to fig. 12, a plate/end piece assembly 124 according to a sixth embodiment of the present invention is shown. Assembly 124 includes a curved top end piece 126, a curved plate 128, and a curved top end piece 130. The bends are formed in a direction perpendicular to the internal channels in the bent plate 128. The end pieces 126 and 130 and the bent plate 128 are assembled into a heat exchange assembly using the methods described above. In assembled form, the assembly 124 enhances the vertical compression load capacity of the heat exchange assembly formed thereby. This configuration may be used in applications requiring multiple heat exchange assemblies that can be placed in a stacked arrangement within the available space.

Referring to fig. 13, a plate/end piece assembly 132 is shown according to a seventh embodiment of the present invention. In this embodiment, the inlet and outlet members 22 and 24 are located on the front and rear sides of the assembly 132, respectively. This shows an embodiment where corresponding components may be provided at other locations on the heat exchange assembly of the present invention, depending on the application, installation, etc. Alternatively, the bottom fluid manifold may include inlet and outlet conduits for receiving and discharging internal heat exchange fluid within the heat exchange assembly. It should be noted that the inlet and outlet members 22 and 24 may also be located on the top and bottom portions 95 and 97 of the manifolds 92 and 94, respectively.

In some cases, condensation may occur on the external surface of the plates as the apparatus of the present invention exchanges heat, with the condensate running down the plates to the bottom of the module. In this case it may be beneficial to provide a collector of condensate or any liquid, which may be formed or provided on the outer surface of the plate.

Referring to fig. 14, bottom fluid manifold 94 may include a sidewall 100. The side walls 100 serve to keep liquid (e.g., condensed products) from flowing down the surface of the plate 16 and preventing the liquid from becoming entrained in the external fluid medium passing through the gap 20. The collected liquid flows to one side of the manifold 94 where it enters a drain conduit 104 through a drain tube 102 located between the plates 16. The drain conduit 104 extends longitudinally of the assembly 80. The liquid is finally discharged from the drain conduit 104 through the outlet member 84.

The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims. Example 1

A heat exchange assembly as shown in fig. 7 was manufactured and tested. The assembly is comprised of a plurality of flat panels extruded from vinyl polymer and top and bottom end members made from polyvinyl chloride. Each flat plate has a thickness of about 0.1 inch, a width of about 13 inches, and a length of about 27 inches. The diameter of the passageway extending through the flat plate is about 0.08 inches. Each end piece is about 0.23 inches thick and 15.5 inches wide. The end piece is shaped similarly to that shown in fig. 9A and 9D. Polymethyl methacrylate is used as an adhesive to bond the end members and the flat plate. The exposed surface of the flat sheet has a large collection of acrylic fibers to form a porous surface. The acrylic fiber was 15 mil long, and in this test, the assembly consisted of 14 flat panels.

Detecting the component in the following cases:

air temperature at inlet 86 deg.F

Humidity of air at inlet 1b dry air contains 0.02311 b water

Inlet air velocity 640fhm

Cooling medium inlet temperature of 75 ° F

Cooling medium flow rate 3gpm

42% concentration lithium chloride solution at the inlet of the desiccant

Desiccant flow rate 250m 1/min

The following measurements were detected:

air temperature at outlet 86 ° F

The air humidity 1b at the outlet contains 0.01141 b water in the dry air

Claims (25)

1. A heat exchange assembly comprising:

a plurality of spaced apart plates, each of said plurality of plates including a plurality of channels extending internally thereof from a first end to a second end for directing a flow of heat exchange fluid within a first plate;

a plurality of first end pieces and a plurality of second end pieces equal in number to the number of plates, each of said first end pieces and second end pieces comprising a recessed area for fluidly connecting and coupling with the first ends and second ends of the plates, respectively, and adapted to be attached in a stacked fashion to adjacent first and second end pieces, each of said first end pieces and second end pieces further comprising at least one cavity to enable a heat exchange fluid to enter and exit the plates or to rotate the fluid 180 ° within the plates to create a fluid passageway between an entry point and an exit point of the fluid; and

at least two fluid conduits pass through the plurality of first and second end pieces of the stack to provide a first fluid path between the parallel fluid entry point and the fluid supply inlet of adjacent plates and a second fluid path between the parallel fluid exit point and the fluid discharge outlet of adjacent plates, whereby the heat exchange fluid travels along the parallel channels through each plate.

2. The heat exchange assembly of claim 1 wherein adjacent rotating chambers longitudinally aligned within the stacked plurality of first and second end members are in fluid communication via a fluid bypass conduit.

3. The heat exchange assembly of claim 1 wherein adjacent rotating chambers longitudinally aligned within the stacked plurality of first and second end members are in fluid communication through a bypass channel.

4. The heat exchange assembly of claim 1 wherein the recessed areas have a depth that is the same as the thickness of the flat plate.

5. A heat exchange assembly as claimed in claim 1, in which the recessed regions have a depth less than the thickness of the plates and the opposed surfaces of the recessed regions of the respective first and second end members include recessed portions for receiving the projecting ends of adjacent plates.

6. A heat exchange assembly as claimed in claim 1, in which the depth of the recessed region is greater than the thickness of the flat plate and the opposed surfaces of the recessed regions of the respective first and second end members include raised portions for fitting with the ends of an adjacent flat plate within the recessed regions of an adjacent end member.

7. A heat exchange assembly as defined in claim 1 wherein said plurality of plates are bent in a direction perpendicular to the longitudinal axis of the plates, said first and second end members being bent in the same manner.

8. The heat exchange assembly of claim 1, wherein there is a fluid supply inlet and a fluid exhaust outlet in the stacked plurality of first and second end member regions, including at least one of front and rear, end, top and bottom, or combinations thereof.

9. The heat exchange assembly of claim 1, further comprising:

and second fluid releasing means for releasing a second fluid onto the surfaces of the plurality of plates proximate the ends thereof.

10. The heat exchange assembly of claim 9, further comprising:

a collection device adjacent the second ends of the plurality of plates for collecting the second fluid as it flows across the surface portion from the first ends to the second ends thereof.

11. The heat exchange assembly of claim 1, further comprising:

a collection device proximate the second ends of the plurality of plates for collecting any fluid that may fall from the plates.

12. The heat exchange assembly of claim 9, wherein the second fluid release comprises:

a supply conduit extending longitudinally within the stacked plurality of first end pieces to provide a second fluid;

a plurality of supply lines, each supply line extending from a supply conduit to each plate within each first end piece; and

a distribution network extending from and in fluid communication with each supply line for releasing a second fluid onto a surface portion proximate the first end of the respective plate.

13. A heat exchange assembly as set forth in claim 12 wherein said distribution network further includes a plurality of distribution slots in fluid communication with said supply line through which the second fluid is discharged onto surface portions of the respective plates proximate the first ends thereof.

14. The heat exchange assembly of claim 13, wherein the plurality of distribution slots extend downwardly along both sides of each first end member.

15. The heat exchange assembly of claim 13 wherein each of the plurality of distribution slots extends along a linear path.

16. The heat exchange assembly of claim 13 wherein the plurality of distribution slots each extend along a non-linear path.

17. The heat exchange assembly of claim 12 wherein the plurality of distribution grids further comprise one or more apertures through which the second fluid passes from the supply line to the surface portion proximate the first end of the respective plate.

18. A heat exchange assembly as set forth in claim 12 wherein said plurality of distribution meshes comprise a porous material through which the second fluid flows from the supply line to the surface proximate the first end of the respective plate.

19. The heat exchange assembly of claim 12, wherein the first end piece includes a purge through-hole forming a purge chamber within the stacked plurality of first end pieces, the purge chamber in fluid communication with a supply line opposite the plurality of supply conduits to bypass a portion of the second fluid to the distribution network.

20. The heat exchange assembly of claim 12, wherein the collection device comprises:

a pair of sidewalls, each extending around the periphery of the stacked plurality of second end pieces for collecting a second fluid flowing along the plurality of flat surfaces from the first end to the second end thereof; and

a drain tube extending longitudinally within the stacked plurality of second end pieces for receiving and draining the collected second fluid.

21. The heat exchange assembly of claim 12 wherein the recessed area of the second end member includes a beveled edge portion for urging the second fluid toward the drain.

22. The heat exchange assembly of claim 20,

the side wall adjacent the drain pipe includes a trailing edge dam; and

the side wall opposite the drain tube includes a leading edge air dam.

23. The heat exchange assembly of claim 9 wherein the second fluid is a liquid desiccant.

24. The heat exchange assembly of claim 1 further comprising a cover plate connected at each end thereof to the first and second end members.

25. A heat exchange assembly comprising:

a plurality of spaced apart plates, each plate including a plurality of channels extending internally therefrom from one end to the other end for directing a flow of heat exchange fluid within a first plate;

a plurality of end members equal in number to the number of plates, each end member comprising a recessed area adapted to be movably connected and coupled to a first end and a second end of a plate and adapted to be attached to an adjacent end member in a stacked configuration, each end member further comprising at least one cavity to enable a heat exchange fluid to enter and exit the plate or to rotate the fluid 180 ° within the plate to create a flow path between an entry point and an exit point of the fluid;

a fluid rotation device disposed at the second end of the plate for rotating a fluid stream entering the plate; and

a fluid supply inlet and a fluid discharge outlet, each inlet and outlet being connected to an attached end member and arranged in such a way that the heat exchange fluid travels along parallel channels through the respective plate.