WO2007016422A2

WO2007016422A2 - Hybrid heat exchanger

Info

Publication number: WO2007016422A2
Application number: PCT/US2006/029587
Authority: WO
Inventors: Mark D. Mirolli
Original assignee: Recurrent Engineering, Llc
Priority date: 2005-08-02
Filing date: 2006-08-01
Publication date: 2007-02-08
Also published as: WO2007016422A3; US20070029077A1

Abstract

A hybrid exchanger utilized to heat a working fluid utilizing counter current heat exchange from a heat source fluid. The plates of the hybrid heat exchanger are configured to be welded to provide a more robust design while also allowing optimum heat exchange of the working fluid. In another embodiment, the hybrid heat exchanger includes a plate assembly and shell combination construction. The plate assembly and shell combination provides both optimized counter current heat exchange, while also controlling leakage of fluid from the hybrid heat exchanger. The plates of hybrid heat exchanger have a plurality of fluid bores which facilitate the exchange of fluids including inlet and outlet ports for both the working fluid and the heat source fluid. The bores of the plates include an open mouth having a greater clearance which allows for optimized flow of fluid while also allowing for simplified cleaning and maintenance of the hybrid heat exchanger.

Description

HYBRID HEAT EXCHANGER

BACKGROUND OF THE INVENTION

1. The Field of the Invention The present invention relates to a thermodynamic system. In more particular, the present invention relates to a hybrid heat exchanger for facilitating the heating of a working fluid utilizing counter current heat exchange.

2. The Relevant Technology

Thermodynamic systems which facilitate the heating or cooling of a working fluid have long been utilized in commercial and residential implementations. Typically, such thermodynamic systems utilize a heat exchanger to heat or cool a working fluid which is then utilized to perform specified functions subsequent to the heat exchange process. For example, in electricity generation systems, such counter current heat exchangers are utilized to heat the working fluid to a desired level for use in driving a turbine of a generator.

Traditional heat exchangers utilize a shell and tube configuration for heating of the working fluid. The shell and tube configuration consists of a plurality of rubes nestled within an outer shell. The working fluid is pumped through the tubes while the heat source fluid or other heating component is contained within the shell exterior to the tubes. As the fluid flows through the tubes, the heating component within the shell heats the working fluid to desired parameters. One problem with traditional shell and tube configurations is that heat exchange between the heat source fluid and the working fluid can be somewhat inefficient, resulting in a much larger heat exchange unit, which provides a lower amount of heat energy, to a smaller volume of working fluid than is achievable with present systems.

Plate type heat exchangers were developed to overcome many of the inefficiencies which were present in shell and tube heat exchange designs. Plate heat exchangers utilize a plurality of plates which are positioned adjacent one another. The working fluid and heat source are allowed to flow between alternating plates. By being allowed to flow between alternating plates, a large amount of working fluid can be heated in a relatively small space, but in a highly efficient manner. As a result, not only is the size of the heat exchanger much smaller, but a larger amount of working fluid is able to be heated to a higher temperature parameter than available with traditional technologies.

One deficiency of plate heat exchangers is the sealing mechanism utilized between plates. The sealing mechanism utilized between plates typically comprises a gasket seal which controls the movement of fluid while also preventing leakage of the fluid from between the plates. The difficulty associated with gasket designs is the fact that the gaskets do not provide an effective sealing mechanism. Additionally, gaskets tend to wear much more quickly and to a greater extent than and other components of the plate heat exchanger. As a result, the gaskets need to be serviced and/or replaced requiring a greater amount of maintenance and attention to the heat exchanger than may otherwise be desired.

The benefits of the smaller size and increased heating capabilities of plate heat exchangers have traditionally been considered to outweigh the negatives required by the additional service and maintenance requirements of plate heat exchangers. However, increased maintenance is not the only deficiency of such designs. Another problem experienced by plate heat exchangers, is the fact that occasionally, even with the gaskets in place, the working fluid and/or the heat source fluid may leak between plates and be exposed to the external environment. Exposure of fluid to the external environment can be particularly problematic when one or both of the heat source fluid and the working fluid comprise a multi-component working fluid, such as water/ammonia mixture. Exposure of ammonia to the external environment can pose potential safety hazards and/or environmental contamination.

Some heat exchangers utilize an accordion-type system in which the ends of the accordion are bonded together to minimize leakage of fluid from the heat exchanger. However, the applicability and manufacturing constraints limit the size of such heat exchangers to smaller implementations such as residential and/or food service units in which the accordion-type design is sufficient to provide the amount of fluid flow and counter current heat exchange needed for such smaller thermodynamic systems and the respective less stringent technical requirements. Additionally, the type and variety of working fluids and heat source fluids that can be utilized with such accordion-type units are somewhat limited, additionally minimizing the number of systems in which such units can be utilized.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to a hybrid exchanger utilized to heat a working fluid utilizing counter current heat exchange from a heat source fluid. According to one embodiment of the present invention, the plates of the hybrid heat exchanger are configured to be welded to provide a more robust design while also allowing optimum heat exchange of the working fluid.

In another embodiment, the hybrid heat exchanger includes a plate assembly and shell combination construction. The plate assembly and shell combination provides both optimized counter current heat exchange, while also controlling leakage of fluid from the hybrid heat exchanger.

In another embodiment, the plates of hybrid heat exchanger have a plurality of fluid bores which facilitate the exchange of fluids including inlet and outlet ports for both the working fluid and the heat source fluid. The bores of the plates include an open mouth having a greater clearance which allows for optimized flow of fluid while also allowing for simplified cleaning and maintenance of the hybrid heat exchanger.

These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

Figure 1 is a perspective view of the plate core assembly of a hybrid heat exchanger illustrating counter current heatexchange of a working fluid and heat source fluid. Figure 2 is a perspective view of a hybrid heat exchanger depicting a plate core assembly and shell of the hybrid heat exchanger, according to one embodiment of the present invention.

Figure 3 is perspective view of a hybrid heat exchanger showing the hybrid heat exchanger fully assembled and ready for operation. Figure 4 is a close-up perspective view of plates of the hybrid heat exchanger, illustrating the configuration of the welds allowing for proper counter current heat exchange of a heat source fluid and a working fluid.

Figure 5 is a front perspective view of first and second plates depicting the flow of fluids from inlet and outlet bores of the plates. Figure 6 is block diagram illustrating the manner in which a hybrid heat exchanger having a plurality of plate core assemblies and a single shell to provide a plurality of components within a thermodynamic system.

Figure 7 is a block diagram illustrating a thermodynamic system in which a plurality of hybrid heat exchangers can be utilized with a single shell to incorporate a plurality of units according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a hybrid exchanger utilized to heat a working fluid utilizing counter current heat exchange with a heat source fluid. According to one embodiment of the present invention, the plates of the hybrid heat exchanger are configured to be welded to provide a more robust design while also allowing optimum heat exchange of the working fluid. In another embodiment, the hybrid heat exchanger includes a plate assembly and shell combination construction. The plate assembly and shell combination provides both optimized counter current heat exchange, while also controlling leakage of fluid from the hybrid heat exchanger. In another embodiment, the plates of hybrid heat exchanger have a plurality of fluid bores which facilitate the exchange of fluids including inlet and outlet ports for both the working fluid and the heat source fluid. The bores of the plates include an open mouth having a greater clearance which allows for optimized flow of fluid while also allowing for simplified cleaning and maintenance of the hybrid heat exchanger. In the illustrated embodiment, hybrid heat exchanger 10 includes a plate core assembly 11. Plate core assembly 11 allows for heating of a working fluid in counter current heat exchange with a heat source fluid. It will be understood that the term working fluid is utilized to describe any fluid medium which is utilized in counter current heat exchange to provide a desired temperature or other parameter, which is later utilized to facilitate operation of the thermodynamic system. For example, the working fluid can comprise a multi-component working fluid, such as water and ammonia mixture. In another embodiment, the working fluid comprises water, geothermal brine, or other fluid as part of a Rankin or other cycle. Additionally, it will be understood that a heat source fluid can comprise any type of heat source, including, but not limited to, fluids, vapors, heated gases, a spent working fluid, or any other source of heat that can be utilized to heat the working fluid.

In the illustrated embodiment, plate core assembly 11 comprises plates 12a-n, a fixed cover 14, a moveable cover 16, an upper horizontal frame member 18, a lower horizontal frame member 19, and tightening bolts 20a-b. In the illustrated embodiment, plates 12a-n are positioned between fixed cover 14 and moveable cover 16. Upper horizontal frame member 18 is positioned on top of fixed cover 14 and moveable cover 16. Lower horizontal frame member 19 is positioned between and below fixed cover 14 and moveable cover 16.

During assembly of plate core assembly 11, the moveable cover 16 is removed and plates 12a-n are slid along upper horizontal frame member 18, while being supported by lower horizontal frame member 19. In the illustrated embodiment, plates 12a-n include a slot which can be slid along the upper horizontal frame member such that the upper horizontal frame member functions as a support to the upper horizontal frame members both during assembly and subsequent to assembly of the plate core assembly. Additionally, the plates 12a-n include a cut-out component that can be slid along the lower horizontal frame member such that the lower horizontal frame member acts as a guide and support to the plates 12a-n during assembly and during operation of the plate core assembly 11. Subsequent to assembly of the plate core assembly 11, the moveable cover 16 can be removed from the other components of the plate core assembly 11 , such that components of the plate core assembly 11 , including plates 12a-n, can be serviced to maintain proper operation of the plate core assembly 11. Tightening bolts 20a-c are provided to finalize assembly of the plate core assembly 11. Tightening bolts 20a-c are positioned relative to fixed cover 14 and moveable cover 16, such that tightening of the tightening bolts 20a-c securely fastens fixed cover 14 relative to moveable cover 16, maintaining the positioning and configuration of plates 12a-n. In the illustrated embodiment, a working fluid and a heat source fluid are pumped into the plate core assembly 11 to allow for a counter current heat exchange to heat the working fluid for use in other portions of the thermodynamic cycle. As will be appreciated by those skilled in the art, the working fluid can also be cooled or heated to other parameters as desired depending upon the type of thermodynamic cycle being utilized. For the sake of clarity, and to more clearly discuss the present invention, the heat source fluid and working fluid are discussed in terms of heating the working fluid to more clearly illustrate operation of the present invention and should in no terms be considered to be limiting in nature. In the illustrated embodiment, the plate core assembly 11 includes a working fluid inlet 22, a working fluid outlet 24, a heat source fluid inlet 26, and a heat source fluid outlet 28. In the illustrated embodiment, working fluid inlet 22, working fluid outlet 24, heat source fluid inlet 26, and heat source fluid outlet 28 are positioned in fixed cover 14 to facilitate the flow of fluids to plates 12a-n. As will be appreciated by those skilled in the art, the working fluid inlet, working fluid outlet, heat source fluid inlet, heat source fluid outlet, can be positioned in a variety of components, juxtapositions, and configurations, without departing from the scope and spirit of the present invention.

In the illustrated embodiment, the working fluid is pumped from the exterior or the plate core assembly to the working fluid inlet 22. The working fluid then flows from the working fluid inlet 22 to the interior of the plate core assembly 11 such that the working fluid comes in contact with plates 12a-n. The working fluid is then defused intermittently between plates 12a-n, such that it is heated by heat source fluid also positioned with intermittent contact between plates 12a-n. In this manner, the working fluid is heated by the heat source fluid with the plate core assembly. Subsequent to heating of the working fluid, the working fluid is pushed from between the plates 12a-n to the working fluid outlet from the pressurization provided at the working fluid inlet. As the working fluid flows from the working fluid outlet 24, it is then allowed to move toward other components of the thermodynamic system to be further processed and/or utilized in the thermodynamic cycle as designed. The heat source fluid is pumped from the exterior of the plate core assembly 11 to the heat source fluid inlet 26. From the heat source fluid inlet 26, the working fluid is intermittently passed between plates 12a-n. As the working fluid passes between plates 12a-n, the working fluid heats the working fluid which is also intermittently passing between plates 12a-n to provide desired heating of the working fluid utilizing counter current heat exchange. The pressure with which the heat source fluid is pumped to the heat source fluid inlet also provides the desired pressurization to pump fluid out through the heat source fluid outlet 28 and to the other components of the thermodynamic system as needed.

In the illustrated embodiment, fixed plates 12a-n include a working fluid inlet bore 38, a working fluid outlet bore 40, and a heat source inlet bore 50, and a heat source outlet bore (not shown). For example, plate 12a includes a working fluid inlet bore 38a, and working fluid outlet bore 40a. Heat source inlet bore 50a and heat source outlet bore (not shown) perform essentially the same function and have a similar design as working fluid inlet bore 38 and working fluid outlet bore 40 relative to the heat source fluid that the working fluid inlet bore 38a and the working fluid outlet bore 40a have in connection with the working fluid.

Plates 12a-n are designed such that the passage of working fluid is permitted on one side of a plate while the passage of heat source fluid is permitted on the other side of the plate. In this manner, the heat can be passed from the heat source fluid to the working fluid by means of the plate core assembly 11. In the illustrated embodiment, the working fluid passes from the working fluid inlet 22 to the working fluid inlet bore 38a. As previously discussed, each of plates 12a-n include a working fluid inlet bore which allows passage of the working fluid along the length of the stack of plates 12a-n.

As the working fluid passes through the working fluid inlet bores 38a-n of plates 12a-n, an amount of fluid passes from the working fluid inlet between every other plate of plates 12a-n within the plate core assembly 11. For example, as the working fluid passes from working fluid inlet bore 38a of plate 12a to working fluid inlet bore 38b of plate 12b, an amount of working fluid passes between plates 12a and 12b as inter plate working fluid flow.

As the working fluid passes from working fluid inlet bore 38b to working fluid inlet bore 38c, the space between plate 12b and plate 12c is sealed such that working fluid does not pass to the space between plate 12b and plate 12c. As such, the entire amount of fluid that passed from working fluid inlet bore 38b also passes out of working fluid inlet bore 38c. As the working fluid passes between working fluid inlet bore 38c and working fluid inlet bore 38d, an amount of fluid is allowed to pass into the area between plates 12c and 12d such that an amount of interplate working fluid flow 34 occurs between plates 12c and 12d. While only a portion of the total amount of working fluid that is introduced into plate core assembly 11 through working fluid inlet 22 is allowed to pass through each of the interplate working fluid flow areas, the entire amount of working fluid that is introduced through working fluid inlet 22 eventually is passed between the interplate heat source fluid flows when considered in combination. In other words, the sum of the total amount of working fluid that flows between each of the interplate working fluid flows between plates 12a and 12n is equivalent to the amount of working fluid that is introduced into plate core assembly through working fluid inlet 22.

As the working fluid moves from the bottom of the interplate working fluid flow areas (see e.g. interplate working fluid flow areas 30, 32) along the length of the plates 12a-n, the fluids eventually exits through the working fluid outlet bore 40a-n of plates 12a-n. As previously discussed, as the working fluid passes between plates 12a-n, it is heated by the heat source fluid which is also passing between plates 12a-n. Thus, the working fluid that exits the interplate working fluid flow areas between plates 12a-n and exits the working fluid outlet bore 40, comprises a heated working fluid which has parameters to be utilized in subsequent portions of the thermodynamic cycle. While only a portion of the total amount of working fluid passes from individual interplate working fluid flow ai-eas to the working fluid outlet bores 40, the total amount of working fluid that exits the working fluid outlet bores in combination provide a fluid flow from the working fluid outlet 24 that is commensurate with the amount of fluid entering the plate core assembly 11 through the working fluid inlet 22. In the illustrated embodiment, a heat source fluid is shown being pumped into the heat source fluid inlet 26. From the heat source fluid inlet 26, the heat source fluid passes through heat source inlet bores 50 of the individual plates 12a-n. As the working source fluid passes between plates 12b and 12c, a small amount of working fluid is allowed to pass into the interplate heat source fluid flow area 32 between plates 12b and 12c. The remaining heat source fluid, which comprises the majority of the working heat source fluid which was introduced from heat source inlet 26, passes through the heat source inlet bore of plate 12c.

As the heat source fluid passes from the heat source inlet bore of plate 12c to the heat source inlet bore of plate 12d, the area between plates 12c and 12d corresponding with the heat source inlet bores of plates 12c and 12d is sealed, preventing the passage of heat source fluid to the space between plates 12c and 12d. As a result, the entire amount of heat source fluid that passes from the heat source inlet bore 50 of plate 12c passes through the heat source inlet bore 50 of plate 12d. As the heat source fluid passes from the heat source inlet bore 50 of plate 12d to the heat source inlet bore of plate 12e, an amount of heat source fluid is allowed to pass to the interplate heat source fluid flow area 36, between plates 12d and 12e. While the amount of heat source fluid that passes between the interplate heat source fluid flow areas of plates 12a-n is minimal for each individual interplate heat source fluid flow area, the sum of the total amount of fluid flow for all of the interplate heat source fluid flow areas is the same as the amount of fluid which is introduced from the heat source fluid inlet 26 and expelled from the heat source fluid outlet 28 of the plate core assembly 11.

As the heat source fluid passes through interplate heat source fluid flow area 32, the heat from the interplate heat source fluid flow 32 is transferred to the working fluid in interplate working fluid flow 30 and interplate working fluid flow 34 through plates 12b and 12c. In like manner, the heat from the interplate heat source fluid flow 36 is utilized to heat the working fluid flowing through the interplate working fluid flows on either side of plates 12e and 12d. In this manner, counter current heat exchange is utilized to use the heat source fluid to heat the working fluid on alternating interplate heat source fluid flow areas and interplate working fluid flow areas. This provides both a desired efficiency of heat exchange while also allowing for a desired volume of total working fluid to be heated within the plate core assembly 11.

According to one embodiment of the present invention, the plates are welded to one another to provide the desired flow of working fluid and heat source fluid between the plates, a more robust seal design, and a greater overall system integrity. In this manner, each of the plates is welded to the adjacent plates in a manner such that the heat source inlet bores allow for passage of the heat source fluid to the interplate heat source fluid flow areas while preventing passage of the heat source fluid to the interplate working fluid flow areas. Additionally, the working fluid inlet bores are aligned such that working fluid can pass through the interplate working fluid flow areas, while preventing passage of the working fluid to the interplate heat source fluid flow areas. In this manner, the interplate working fluid flow areas contain exclusively working fluid while the heat source interplate fluid flows contain exclusively heat source fluid. Because the interplate working fluid flow areas and the interplate heat source fluid flow areas are positioned alternatively on opposite sides of adjacent plates, a temperature gradient can be provided within the plate core assembly to provide optimal heating of the working fluid within the plate core assembly.

As will be appreciated by those skilled in the art, a variety of types and configurations of heat exchangers and plate core assemblies of the heat exchangers can be utilized without departing from the scope and spirit of the present invention. For example, in one embodiment, the working fluid inlet and working fluid outlet are positioned on one end of the plate core assembly, while the heat source fluid inlet and the heat source fluid outlet are positioned on the other end of the plate core assembly. In another embodiment, the working fluid inlet and the heat source fluid outlet are positioned on one end of the plate core assembly, while the working fluid outlet and the heat source fluid inlet are positioned on the other end of the plate core assembly. In another embodiment, both the working fluid inlet and the heat source fluid inlet are positioned at the top of the plate core assembly such that the working fluid and the heat source fluid migrate from the top of the plates to the bottom of the plates and then are pumped to the working fluid outlets and the heat source fluid outlets from the bottom of the plates. Figure 2 is a perspective view of a hybrid heat exchanger 10 in which the plate core assembly 11 has been flilly assembled and is positioned to be placed inside a shell 42. In the illustrated embodiment, shell 42 is configured to entirely contain plate core assembly 11. Shell 42 provides a fluid-tight seal, preventing the leakage of fluids that leak from plate core assembly 11 to the external environment. In the illustrated embodiment, shell 42 includes a chamber 44. The plate core assembly 11 is introduced into the chamber 44 of shell 42 and the shell 42 is sealed to prevent leakage of any fluid to the external environment.

According to one embodiment of the present invention, only the interplate working fluid flow areas between plates 12a-n are welded, while the interplate heat source fluid flow areas are not welded. In this embodiment, the working fluid is contained within the interplate working fluid flow areas by the welding of the plates, while the heat source fluid is contained within the heat source interplate fluid flow areas by the shell. In another embodiment, the interplate heat source fluid flow areas are sealed by welding of the plates on either side of the interplate heat source fluid flow areas while the working fluid that flows in the interplate working fluid flow areas is contained by the shell.

Figure 3 is a perspective view of the hybrid heat exchanger 10 subsequent to sealing of the plate core assembly 11 (see Figure 3) within shell 42. In the illustrated embodiment, shell 42 working fluid inlet 22a, working fluid outlet 24a, heat source fluid inlet 26a, and heat source fluid outlet 28a. In the illustrated embodiment, the working fluid is pumped into the hybrid heat exchanger 10 through the working fluid inlet 22a. The heat source fluid is introduced to the hybrid heat exchanger 10 through the heat source fluid inlet 26a. As previously discussed with reference to Figures 1 and 2, the working fluid is heated by the heat source fluid in counter current heat exchange within the plate core assembly 11 (see Figure 2). Subsequent to heating within the plate core assembly 1 1 , the working fluid is expelled from the hybrid heat exchanger 10 from the working fluid outlet 24a. The heat source fluid is expelled from the hybrid heat exchanger from the heat source fluid outlet 28.

As will be appreciated by those skilled in the art, a variety of types and configurations of hybrid heat exchangers can be utilized without departing from the scope and spirit of the present invention. For example, in one embodiment, the plate core assembly is introduced into the shell through the top of the shell and a lid component of the shell is sealed over the top of the plate core assembly 11. In another embodiment, the working fluid inlet, working fluid outlet, heat source fluid inlet, and heat source fluid outlet are positioned in one or more of the top and sides of the shell of the hybrid heat exchanger. In another embodiment, the shell has a molded design which is configured to entirely envelope the plate core assembly.

Figure 4 is a close-up perspective view of plates 12c, 12d, and 12e of the hybrid heat exchanger. In the illustrated embodiment, plates 12d and 12e are shown welded to one another as part of the plate core assembly 11. Plate 12c is shown previous to being welded to plate 12d. In the illustrated embodiment, a weld line 46 is provided on plate 12c and 12d to illustrate the line of welding between plates 12c,

12d and other adjacent plates to provide for proper flow of fluid to the interplate worldng fluid flow areas and the interplate heat source fluid flow areas (see Figure 1).

The weld line 46 of plate 12c is positioned along the external boundary of plate 12c to control the leakage of fluid from between plates 12c and 12b (not shown). Additionally, the weld associated with the weld line 46 is provided completely surround working fluid Outlet bore 40c and working fluid inlet bore 38c (not shown). In this manner, the weld seals the passage of working fluid from the working fluid inlet bore 38c (not shown) to the interplate heat source fluid flow positioned between plates 12c and 12b (not shown). In contrast, while the weld extends around the outer perimeter of heat source fluid inlet bore 50c, it does not completely seal heat source fluid inlet bore 50c. As a result, heat source fluid can pass to the interplate heat source fluid flow area between plates 12c and 12b (not shown). In this manner, weld associated with weld line 46 of plate 12c controls the passage of working fluid while permitting the passage of heat source fluid into the interplate heat source fluid flow area between plates 12c and 12b (not shown).

The weld associated with weld line 46 of plate 12d extends along the outer perimeter of plate 12d while completely circumscribing the heat source fluid inlet bore 50d and heat source outlet bore 52d (not shown) to prevent the passage of heat source fluid into the interplate working fluid flow area between plates 12c and 12d. In contrast, the weld of plate 12d allows the passage of fluid from working fluid inlet bore 38d (not shown) into the interplate working fluid flow area between plates 12d and 12c and out of the working fluid outlet bore 40a.

In the illustrated embodiment, the heat source interplate fluid flow area and the interplate working fluid flow area include a plurality of channels 48. Channels 48 facilitate the gradual and controlled flow of fluid from the working fluid inlet bores to the working fluid outlet bores and from the heat source fluid inlet bores to the heat source fluid outlet bores. In other words, channels 48 dissipate the working fluid and heat source fluids along the entire surface of the plates to allow for both a more controlled and gradual movement of fluid from the heat source fluid inlet bores and working fluid inlet bores to the working fluid outlet bores and heat source fluid outlet bores while also providing a maximum desired degree of heat exchange along the plates.

According to one embodiment of the present invention, the portion between plates 12c and 12d, which facilitate the flow of fluid into either the interplate working fluid flow area or the interplate heat source fluid flow area from either the working fluid inlet bore 38 or the heat source fluid inlet bore 50, is provided with an open mouth configuration providing greater clearance allowing for desired flow of fluid, while also allowing for simplified cleaning and maintenance of the plates. For example, the more open mouth configuration and associated clearance can allow for cleaning without needing to remove and separate plates within the plate core assembly. In another embodiment, the more open mouths allow for cleaning of the plates, working fluid bores, and heat source fluid bores, by simply utilizing a flushing fluid with the hybrid heat exchanger without any disassembly of the hybrid heat exchanger or plate core assembly.

Figure 5 is a front perspective view of plates 12c and 12d according to one embodiment of the present invention. In the illustrated embodiment, plate 12c comprises a working fluid inlet bore 38c, a working fluid outlet bore 40c, a heat source fluid inlet bore 50c, and a heat source fluid outlet bore 52c. The weld line 46 of plate 12c runs along the entire perimeter of plate 12c. Additionally, the weld line 46 entirely circumscribes working fluid inlet bore 38c and working fluid outlet bore 40c. In contrast, the weld 46 does not entirely circumscribe heat source fluid inlet bore 50c and heat source fluid outlet bore 52c, allowing the. passage of heat source fluid from heat source fluid inlet bore 50c through channels 48 of interplate heat source fluid flow area 32 and out through heat source fluid outlet bore 52c.

Plate 12d comprises a working fluid inlet bore 38d₃ a working fluid outlet bore 4Od₃ a heat source fluid inlet bore 5Od, and heat source fluid outlet bore 52d. Weld line 46 of plate 12d runs along the entire outer perimeter of plate 12d. Additionally, weld 46 entirely circumscribes heat source fluid inlet bore 5Od and heat source fluid outlet bore 52d. In this manner, weld 46 prevents the flow of fluid from heat source fluid inlet bore 50d to the interplate working fluid flow area 34. In contrast, weld 46 does not entirely circumscribe working fluid inlet bore 38d and working fluid outlet bore 4Od, allowing the passage of fluid from working fluid inlet bore 38d to the channels 48 of interplate working fluid flow area 34 and out working fluid outlet bore 4Od. By alternating plates having weld configurations as depicted in plates 12c and 12d, the flow of working fluid and heat source fluid into interplate working fluid flow areas and interplate heat source fluid flow areas are alternated allowing counter current heat exchange to occur along the length of the plates within a plate core assembly.

Figure 6 is a block diagram of thermodynamic system utilizing a plurality of heat exchangers and heat exchange components according to one embodiment of the present invention. In the illustrated embodiment, a plurality of heat exchange components are provided within a single hybrid heat exchanger combination unit 54. For example, in one embodiment, the hybrid heat exchanger combination unit comprises a plate core assembly heat exchanger 1 , a plate core assembly heat change 2, and a plate core assembly heat exchanger 3 which are separated from one another and which are enclosed within a single shell.

The plurality of separate plate core assemblies 1, 2, 3 can be housed within a single shell, the single hybrid heat exchanger combination unit 54 which provides the functionality of three individual heat exchangers in a single heat exchange component. The heat core assemblies 1, 2, 3 permit counter current heat exchange to heat the working fluid, while the shell encloses heat core assemblies 1, 2, 3 in combination. In this manner, a single hybrid heat exchanger combination unit 56 can be provided to allow for a quick and efficient assembly of the thermodynamic system without needing to supply and connect separate heat exchange units. Additionally, single hybrid heat exchanger combination unit 54 can simply and efficiently be combined with other thermodynamic subcomponents to provide a quick and easy assemblage of a thermodynamic system having desired features. In the illustrated embodiment, the hybrid heat exchanger combination unit further includes a stream separator which is utilized to separate and direct working fluid flow to a plate core assembly 3 which is positioned in the hybrid heat exchanger combination unit 54 and a plate core assembly 4 which is positioned outside the hybrid heat exchanger combination unit 54.

In addition, the hybrid heat exchanger combination unit 54 includes a plurality of inputs and a plurality of outputs of working fluid and heat source fluid. For example, a heat source inlet is provided between the expansion turbine and the plate core assembly 3. In this embodiment, the heat source fluid from the expansion turbine comprises the spent working fluid. Where the working fluid comprises a multi-component fluid such as ammonia water utilized in a Kalina Cycle, the shell of the hybrid heat exchanger combination unit 54 minimizes leakage of the spent working fluid and the working fluid. In fact, where the thermodynamic cycle comprises a Kalina Cycle, the heat source fluid utilized with plate core assemblies 1 , 2, and 3 comprise a mult-icomponent working fluid. A first working fluid outlet is provided between the stream separator and plate core assembly 4. A second working fluid outlet is provided between the plate core assembly 3 and plate core assembly 5. As will be appreciated by those skilled in the art, a variety of types and configurations of hybrid heat exchanger combination units can be utilized without departing from the scope and spirit of the present invention. For example, in one embodiment, the pump between the condenser and the first plate core assembly is not included within the hybrid heat exchanger combination unit. In another embodiment, the hybrid heat exchanger combination unit includes two or more shells in which the hybrid heat exchanger units and other components of the hybrid heat exchanger combination unit can be utilized.

Figure 7 is an illustrative view of a thermodynamic system utilizing a hybrid heat exchanger combination unit 56, according to another embodiment of the present invention. In the illustrated embodiment, hybrid heat exchanger combination unit 56 includes a heat exchanger 2, a heat exchanger 3, and a heat exchanger 4 and a separator utilized to divide the stream from heat exchanger 2 to heat exchanger 3 and heat exchanger 3. In the illustrated embodiment, a single shell (see Figure 5) is provided to house heat exchanger 2, heat exchanger 3, and heat exchanger 4 and the separator. In the embodiment, heat exchanger 2, heat exchanger 3, and heat exchanger 4 comprise both plate core assemblies (see e.g. plate core assembly 1 1 of Figure 2) and shells (see e.g. shell 42 of Figure 2). In other words, heat exchangers 2, 3, 4 comprise complete hybrid heat exchangers, including the shell, while a supplementary shell is provided to enclose heat exchangers 2, 3,4 to foπn heat exchanger combination unit 56. In the illustrated embodiment, where the thermodynamic cycle comprises a Kalina Cycle, the heat source fluid utilized to heat the working fluid in heat exchangers 2, 3 comprises a multi-component spent stream (e.g. ammonia/water). In contrast, the heat source fluid utilized to heat the working fluid in heat exchanger 4 comprises geothermal brine, industrial waste heat, or another fluid source exterior to the closed loop system.

As will be appreciated by those skilled in the art, a variety of types and configurations of hybrid heat exchanger combination units can be utilized with departing from the scope and spirit of the present invention. For example, in one embodiment, the hybrid heat exchanger combination unit also encloses one or more heat exchangers within a distillation condensation subsystem. In another embodiment, the hybrid heat exchanger combination unit does not enclose a separator unit. In yet another embodiment, the hybrid heat exchanger combination unit is provided to a client in a manner that it can be utilized with existing components of a thermodynamic system to provide desired improvements and/or changes to the thermodynamic system to provide a desired degree and amount of functionality not realized by the existing system. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. What is claimed is:

Claims

1. A hybrid heat exchanger adapted to heat a working fluid for use in a thermodynamic system utilizing a heat source fluid in counter current heat exchange with the working fluid, the hybrid heat exchanger comprising: a plate core assembly comprising; three or more plates positioned adjacent one another such that the working fluid and heat source fluid are positioned on opposite sides of one or more of the three or more plates; a seal positioned between two or more of the three or more plates to minimize leakage of at least one of the working fluid and the heat source fluid; and a shell having a chamber adapted to accommodate the plate core assembly wherein the shell is fluid tight to prevent leakage of the working fluid and the heat source fluid in the event that one or more of the working fluid and the heat source fluid leaks from the plate core assembly.

2. The hybrid heat exchanger of claim 1 , wherein the three or more plates comprise a plurality of plates adapted to allow the passage and counter current heat exchange of the working fluid and the heat source fluid on opposite sides of the plate without mixing the working fluid and the heat source fluid.

3. The hybrid heat exchanger of claim 1 , wherein the seal comprises a weld.

4. The hybrid heat exchanger of claim 3, wherein the weld provides a robust and effective seal between the two or more plates.

5. The hybrid heat exchanger of claim 1, wherein the plates include one or more of a working fluid inlet bore, a working fluid outlet bore, a heat source fluid inlet bore, and a heat source fluid outlet bore.

6. The hybrid heat exchanger of claim 5, wherein the one or more of the working fluid inlet bore, the working fluid outlet bore, the heat source fluid inlet bore, and the heat source fluid outlet bore include an open mouth allowing the passage of one of a working fluid and heat source fluid between the plates.

7. The hybrid heat exchanger of claim 6, wherein the open mouth has an sufficient clearance to permit cleaning of the plates by flushing fluid into one or more of the working fluid inlet bore, the working fluid outlet bore, the heat source fluid inlet bore and the heat source fluid outlet bore from the exterior of the plate core assembly.

8. The hybrid heat exchanger of claim 1, wherein the shell completely envelopes the plate core assembly.

9. A hybrid heat exchanger adapted to heat a working fluid for use in a thermodynamic system utilizing a heat source fluid in counter current heat exchange with the working fluid, the hybrid heat exchanger comprising: a plate core assembly comprising; a plurality of plates positioned adjacent one another; an interplate working fluid flow area positioned between at least two of the plurality of plates and allowing the passage of working fluid between the at least two of the plurality of plates; an interplate heat source fluid flow area positioned between at least a different two of the plurality of plates and allowing the passage of heat source fluid between the at least two of the plurality of plates; a seal positioned between one of the at least two of the plurality of plates forming the interplate heat source fluid flow area or the interplate working fluid flow area, the seal being configured to minimize leakage of at least one of the working fluid and the heat source fluid, wherein the seal comprises a weld configured to allow the passage of working fluid into the interplate working fluid flow area and the passage of heat source fluid into the interplate heat source fluid flow area, while minimizing the passage of working fluid into the interplate heat source fluid flow area and the passage of heat source fluid into the interplate working fluid area.

10. The hybrid heat exchanger of claim 9, wherein the plurality of plates are positioned in a row along the length of the plate core assembly.

1 1. The hybrid heat exchanger of claim 9, wherein a plurality of interplate working fluid flow areas are positioned along the length of the plate core assembly.

12. The hybrid heat exchanger of claim 11, wherein a plurality of interplate heat source fluid flow areas are positioned along the length of the plate core assembly.

13. The hybrid heat exchanger of claim 12, wherein the plurality of interplate working fluid flow areas alternate with the plurality of interplate heat source fluid flow areas along the length of the plate core assembly.

14. The hybrid heat exchanger of claim 9, wherein the each of the plurality of plates are welded to one another.

15. The hybrid heat exchanger of claim 11, wherein the plurality of plates are welded together to form the plurality of interplate working fluid flow areas.

16. The hybrid heat exchanger of claim 15, wherein the weld allows the passage of working fluid into the plurality of interplate working fluid flow areas while minimizing the passage of heat source fluid into the plurality of interplate working fluid flow areas.

17. The hybrid heat exchanger of claim 16, wherein the plurality of plates include a working fluid inlet bore, a working fluid outlet bore, a heat source fluid inlet bore, and a heat source fluid outlet bore and the weld is configured such that passage of working fluid into or out of the plurality of interplate working fluid flow areas from the working fluid inlet bore and the working fluid outlet bore is permitted while the passage of fluid into or out of the heat source fluid inlet bore and the heat source fluid outlet bore is minimized.

18. The hybrid heat exchanger of claim 12, wherein the plurality of plates are welded together to form the plurality of interplate heat source fluid flow areas.

19. The hybrid heat exchanger of claim 18, wherein the weld allows the passage of heat source fluid into the plurality of interplate heat source fluid flow areas while minimizing the passage of working fluid into the plurality of interplate heat source fluid flow areas.

20. The hybrid heat exchanger of claim 19, wherein the plurality of plates include a working fluid inlet bore, a working fluid outlet bore, a heat source fluid inlet bore, and a heat source fluid outlet bore and the weld is configured such that passage of heat source fluid into the plurality of interplate heat source fluid flow areas from the heat source fluid inlet bore and the heat source fluid outlet bore is permitted while the passage of fluid into or out of the working fluid inlet bore and the working fluid outlet bore is minimized.

21. A hybrid heat exchanger combination unit adapted to heat a working fluid for use in a thermodynamic system utilizing a heat source fluid in counter current heat exchange with the working fluid, the hybrid heat exchanger comprising: a first heat exchange component adapted to heat a working fluid to a desired temperature parameter utilizing counter current heat exchange; at least a second heat exchange component adapted to heat a working fluid to a desired temperature parameter utilizing counter current heat exchange; and a shell having a chamber adapted to accommodate the first heat exchange component and the at least second heat exchange component to prevent leakage of the working fluid in the event that the working fluid leaks from the first heat exchange component and the at least second heat exchange component.

22. The hybrid heat exchanger combination unit of claim 21, wherein the first and second heat exchange components comprise plate core assemblies.

23. The hybrid heat exchanger combination unit of claim 22, wherein the first and second heat exchange component comprise heat exchangers.

24. The hybrid heat exchanger combination unit of claim 23, wherein the heat exchangers comprise hybrid heat exchangers having plate core assemblies and shells .

25. The hybrid heat exchanger combination unit of claim 24, wherein the shell of the hybrid heat exchanger combination unit comprises a supplementary shell adapted to prevent the leakage of working fluid to the external environment.

26. The hybrid heat exchanger combination unit of claim 21 . further comprising a stream separator.

27. The hybrid heat exchanger combination unit of claim 21 , wherein one or more of the first heat exchange component and the at least second heat exchange components comprises a plate core assembly and wherein one or more of the first heat exchange component and the at least second heat exchange components comprises a hybrid heat exchanger.

28, The hybrid heat exchanger combination unit of claim 21, wherein the hybrid heat exchanger is configured to be combined with other mechanisms to form a thermodynamic system.

29. A method for implementing a thermodynamic cycle comprising the steps of: expanding a gaseous working stream, transforming its energy into a usable form and producing a spent stream; reheating a spent stream utilizing a hybrid heat exchanger having a plate core assembly positioned within a liquid tight outer shell, to transform its energy into a usable form; heating a multicomponent oncoming liquid working stream by partially condensing the spent stream to preheat and partially evaporate the multicomponent oncoming liquid working stream to produce a heated liquid working stream; and evaporating the heated liquid working stream using heat produced by an external heat source, to form the gaseous working stream.

30. The method of claim 29, wherein the plate core assembly includes a plurality of plates positioned adjacent one another allowing counter current heat exchange of that one or more of the spent stream and the multicomponent oncoming liquid working stream utilizing heat produced by an external heat source.

31. The method of claim 30, wherein the shell includes a chamber adapted to accommodate the plate core assembly wherein the shell is fluid tight to prevent leakage of the fluids utilized in the thermodynamic cycle.

32. A hybrid heat exchanger adapted to heat a working fluid for use in a thermodynamic system utilizing a heat source fluid in counter current heat exchange with the working fluid, the hybrid heat exchanger comprising: a plate core assembly comprising; a plurality of plates positioned adjacent one another; an interplate working fluid flow area positioned between at least two of the plurality of plates and allowing the passage of working fluid between the at least two of the plurality of plates; an interplate heat source fluid flow area positioned between at least a different two of the plurality of plates and allowing the passage of heat source fluid between the at least two of the plurality of plates; a seal positioned between one of the at least two of the plurality of plates forming the interplate heat source fluid flow area or the interplate working fluid flow area, the seal being configured to minimize leakage of at least one of the working fluid and the heat source fluid, wherein the seal comprises a weld configured to allow the passage of working fluid into the interplate working fluid flow area and the passage of heat source fluid into the interplate heat source fluid flow area, while minimizing the passage of working fluid into the interplate heat source fluid flow area and the passage of heat source fluid into the interplate working fluid area ; and a shell having a chamber adapted to accommodate the plate core assembly wherein the shell is fluid tight to prevent leakage of the working fluid and the heat source fluid in the event that one or more of the working fluid and the heat source fluid leaks from the plate core assembly .