High pressure capable liquid to refrigerant heat exchanger

Abstract

A liquid to refrigerant heat exchanger includes a coolant volume that is at least partially defined by a plastic housing and by a metal closure plate. The plastic housing is sealingly joined to the closure plate along an outer periphery of the closure plate. The metal closure plate can be part of a brazed assembly that defines a continuous refrigerant flow path through the heat exchanger between a refrigerant inlet port and a refrigerant outlet port.

Claims

1. A liquid to refrigerant heat exchanger comprising: a coolant volume defined at least partially by a plastic housing and a metal closure plate, the plastic housing being sealingly joined to the closure plate along an outer periphery of the closure plate; a cylindrically shaped inlet manifold for a refrigerant flow arranged within the coolant volume; a cylindrically shaped outlet manifold for the refrigerant flow arranged within the coolant volume; a plurality of refrigerant conduits arranged within the coolant volume and extending between the inlet manifold and the outlet manifold to convey the refrigerant flow from the inlet manifold to the outlet manifold; an inlet fitting block joined to and extending through the closure plate, the inlet fitting block having a first portion arranged within the coolant volume and a second portion arranged outside of the coolant volume, the inlet manifold being joined to the first portion of the inlet fitting block; an outlet fitting block joined to and extending through the closure plate, the outlet fitting block having a first portion arranged within the coolant volume and a second portion arranged outside of the coolant volume, the outlet manifold being joined to the first portion of the outlet fitting block; a refrigerant inlet port arranged on the second portion of the inlet fitting block, the refrigerant inlet port being in fluid communication with an internal volume of the inlet manifold by way of a refrigerant flow path extending through the inlet fitting block; and a refrigerant outlet port arranged on the second portion of the outlet fitting block, the refrigerant outlet port being in fluid communication with an internal volume of the outlet manifold by way of a refrigerant flow path extending through the outlet fitting block.

2. The liquid to refrigerant heat exchanger of claim 1, wherein the closure plate, the inlet manifold, the outlet manifold, the plurality of refrigerant conduits, the inlet fitting block, and the outlet fitting block are joined together by braze joints to define a leak-free refrigerant flow path between the refrigerant inlet port and the refrigerant outlet port.

3. The liquid to refrigerant heat exchanger of claim 1, wherein at least one of the inlet fitting block and the outlet fitting block is joined to both the inlet manifold and the outlet manifold.

4. The liquid to refrigerant heat exchanger of claim 3, wherein the inlet manifold and the outlet manifold are each joined to both the inlet fitting block and the outlet fitting block.

5. The liquid to refrigerant heat exchanger of claim 1, wherein the inlet fitting block and the outlet fitting block each extend through flanged apertures in the closure plate.

6. The liquid to refrigerant heat exchanger of claim 1, wherein the plastic housing is sealingly joined to the closure plate by a peripheral crimp joint.

7. The liquid to refrigerant heat exchanger of claim 1 wherein each of the plurality of refrigerant conduits includes a plurality of sequentially arranged passes through the coolant volume, further comprising a plurality of coolant fins arranged between and joined to adjacent ones of the plurality of sequentially arranged passes.

8. The liquid to refrigerant heat exchanger of claim 1, wherein the coolant volume includes a coolant inlet portion arranged at a first end of the heat exchanger, a coolant outlet portion arranged at a second end of the heat exchanger opposite the first end, and a heat exchange portion arranged between the coolant inlet portion and the coolant outlet portion, the plurality of refrigerant conduits being arranged within the heat exchange portion of the coolant volume.

9. The liquid to refrigerant heat exchanger of claim 8, wherein each of the plurality of refrigerant conduits includes a plurality of sequentially arranged passes through the coolant volume, further comprising a plurality of coolant fins arranged between and joined to adjacent ones of the plurality of sequentially arranged passes.

10. The liquid to refrigerant heat exchanger of claim 9, further comprising a first coolant baffle arranged between the coolant inlet portion and the heat exchange portion of the coolant volume and a second coolant baffle arranged between the coolant outlet portion and the heat exchange portion of the coolant volume, the first and the second coolant baffles each having an aperture that corresponds to an outer periphery of the plurality of coolant fins.

11. The liquid to refrigerant heat exchanger of claim 10, wherein the closure plate, the inlet manifold, the outlet manifold, the plurality of refrigerant conduits, the inlet fitting block, the outlet fitting block, and the plurality of coolant fins are all joined together in a single brazing operation to define a brazed assembly, and wherein the first coolant baffle and the second coolant baffle are assembled to the brazed assembly prior to inserting the brazed assembly into the plastic housing.

12. The liquid to refrigerant heat exchanger of claim 10, wherein the first and the second coolant baffles are each partially received within recessed grooves provided in the plastic housing.

13. The liquid to refrigerant heat exchanger of claim 8, further comprising a coolant inlet port and a coolant outlet port, each formed as an integral part of the plastic housing, the coolant inlet port being configured to direct a flow of coolant into the coolant inlet portion of the coolant volume and the coolant outlet port being configured to receive a flow of coolant from the coolant outlet portion of the coolant volume.

14. The liquid to refrigerant heat exchanger of claim 1, wherein the plastic housing is sealingly joined to the metal closure plate by way of an elastomeric seal and a crimp joint extending along the outer periphery of the metal closure plate.

15. The liquid to refrigerant heat exchanger of claim 14, wherein the elastomeric seal is arranged within a gasket well provided by the plastic housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a liquid to refrigerant heat exchanger according to an embodiment of the invention.

(2) FIG. 2 is another perspective view of the liquid to refrigerant heat exchanger of FIG. 1.

(3) FIG. 3 is a perspective view of portions of the liquid to refrigerant heat exchanger of FIG. 1 prior to final assembly.

(4) FIG. 4 is a partially cut-away perspective view of the liquid to refrigerant heat exchanger of FIG. 1.

(5) FIG. 5 is a side section view of the liquid to refrigerant heat exchanger of FIG. 1.

DETAILED DESCRIPTION

(6) Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.

(7) A liquid to refrigerant heat exchanger 1 that is particularly well-suited to the use of a high-pressure refrigerant is depicted in FIGS. 1-5. Such a heat exchanger can find particular utility in, for example, automotive applications requiring a supply of chilled liquid coolant. Such applications can be particularly useful in electric vehicles, wherein the flow of chilled coolant is used to remove heat from batteries and/or power electronics that are used to provide propulsion to the vehicle. In other applications, such a liquid to refrigerant heat exchanger 1 can be used to provide chilled coolant for other purposes, such as passenger cooling. In still other applications the liquid to refrigerant heat exchanger 1 can be used to reject heat from the refrigerant to a flow of cooling liquid, such as in a heat pump application.

(8) As depicted in the accompanying figures, the liquid to refrigerant heat exchanger 1 includes a plastic housing 3 that is sealingly joined to a metal closure plate 4. The metal closure plate 4 is preferably part of a brazed assembly 2, depicted in FIG. 3. The plastic housing 3 and the metal closure plate 4 together cooperate to define a coolant volume 20 within the liquid to refrigerant heat exchanger 1.

(9) As best seen in FIG. 1, the plastic housing 3 includes a coolant inlet port 21 arranged at one end of the plastic housing 3 and a coolant outlet port 22 arranged at an opposite end of the plastic housing 3. This arrangement allows a flow of coolant 40 to enter into the liquid to refrigerant heat exchanger 1 at the first end through the port 21, to travel through the liquid to refrigerant heat exchanger 1 by traversing the coolant volume 20, thereby exchanging heat with a flow of refrigerant also passing through the liquid to refrigerant heat exchanger 1, and to subsequently be removed from the liquid to refrigerant heat exchanger 1 through the outlet port 22 as either a chilled or heated floor of coolant. In some other embodiments, the coolant inlet port 21 and the coolant outlet port 22 may alternatively be arranged at the same end of the plastic housing 3.

(10) In some especially preferable embodiments, the plastic housing 3 is an injection-molded component. Such a construction allows for the coolant ports 21, 22 to be integrally formed in the plastic housing 3, thereby minimizing the number of discrete parts required. Additional features such as, for example, stiffening ribs and a gasket well, can also be readily included in the plastic housing 3 with such a construction.

(11) The closure plate 4 can be produced as a stamped plate out of, for example, aluminum sheet material. Various features can be provided within the closure plate 4, such as an upturned peripheral flange 17 (as seen in FIG. 3) to be used as a crimp joint for the securing of the plastic housing 3. The closure plate 4 can also be provided with beads 26 formed into the plate to provide structural stiffening of the closure plate 4, as well as to locate and reinforce the gasket well of the plastic housing 3.

(12) The brazed assembly 2 containing the closure plate 4 is depicted in FIG. 3, and is preferably an assembly of aluminum components that are joined together to form a monolithic construction in a single brazing operation. In the exemplary embodiment of FIG. 3, the brazed assembly 2 also includes a pair of cylindrical pipes 5 and 6 that function as manifolds for the refrigerant flow. In the exemplary embodiment, the cylindrical pipe 5 is an inlet manifold for a flow of refrigerant, while the cylindrical pipe 6 is an outlet manifold for the flow of refrigerant. The inlet manifold 5 and the outlet manifold 6 are hydraulically connected by multiple formed tubes 7 that function as refrigerant conduits to convey the refrigerant through the coolant volume 20 from the inlet manifold 5 to the outlet manifold 6.

(13) The refrigerant conduits 7 are preferably flat aluminum tubes having one or more flow channels (not shown) extending therethrough. In particularly preferable embodiments, the refrigerant conduits 7 are aluminum micro-extrusions having a series of parallel-arranged flow channels. Such a construction is known to be particularly well-suited for use with high-pressure refrigerants, as it allows for increased pressure resistance through the use of small hydraulic diameters coupled with relatively thick walls to serve as pressure boundaries.

(14) As best seen in the cross-sectional view of FIG. 5, each refrigerant conduit 7 has a series of U-bends formed to create multiple sequentially arranged passes 19 for the flow of refrigerant through the heat exchanger 1. The ends of each refrigerant conduit 7 are twisted by 90° about the tube-axial direction and are inserted into corresponding slots in the manifolds 5, 6. This allows for a close spacing of the refrigerant conduits 7 along the lengths of the manifolds, thereby maximizing the available outer surface are of the conduits 7 for purposes of heat transfer with the coolant.

(15) Coolant fins 24 are arranged between the successive passes 19 of the conduits 7, and are brazed to the flat outer surfaces of the conduits 7 in order to provide both structural rigidity and surface area enhancement for the efficient transfer of heat to or from the coolant. The coolant fins 24 as depicted are of the lanced and offset type, although other types of fin surfaces can be contemplated. Aluminum side sheets 31 are optionally provided on either end of the stack of conduits 7 and fins 24 in order to both bound the coolant flow and to assist in securing the components prior to and during the brazing process.

(16) The refrigerant inlet manifold 5 and the refrigerant outlet manifold 6 are joined to and supported by a pair of fitting blocks 8, 9. The fitting blocks 8, 9 are spaced apart from one another along the axial lengths of the manifolds 5, 6, and are provided with arcuate recesses to receive the manifolds 5, 6. Each of the fitting blocks extends partially through a flanged aperture 16 in the metal closure plate 4, so that a first portion (e.g. the portion 8a identified in FIG. 5 for the fitting block 8) of the fitting block is located within the coolant volume 20, and a second portion (e.g. the portion 8a identified in FIG. 5 for the fitting block 8) of the fitting block is located outside of the coolant volume 20.

(17) The fitting block 8 is provided with a refrigerant inlet port 10 on the aforementioned second portion 8a, and is therefore referred to as an inlet fitting block. Refrigerant linework from the refrigerant system can be connected to the inlet fitting block 8 in order to deliver a flow of refrigerant 30 from the refrigerant system into the liquid to refrigerant heat exchanger 1 by way of the refrigerant inlet port 10. A refrigerant flow path 18 extends through the inlet fitting block 8 and provides fluid communication between the refrigerant inlet port 10 and an internal volume 12 of the refrigerant inlet manifold 5. The flow of refrigerant 30 can thereby be delivered to the refrigerant inlet manifold 5 and can be subsequently distributed to the flow channels within the refrigerant conduits 7.

(18) In a similar manner, the fitting block 9 is provided with a refrigerant outlet port 11, and is therefore referred to as an outlet fitting block. The refrigerant outlet port 11 is in fluid communication with an internal volume 13 of the outlet manifold 6 in a similar manner to that described for the refrigerant inlet port 10, i.e. by way of a flow channel (not shown) extending through the outlet fitting block 9. After flowing through the refrigerant conduits 7, the refrigerant flow 30 is received into the internal volume 13 and is delivered to the refrigerant outlet port 11. Refrigerant linework from the refrigerant system can also be connected to the outlet fitting block 9 in order to return the flow of refrigerant from the liquid to refrigerant heat exchanger 1 back to the refrigerant system by way of the refrigerant outlet port 11.

(19) The brazed assembly 2 of FIG. 3 can be created by assembling the various components (e.g. the manifolds 5 and 6, the conduits 7, the coolant fins 24, the optional side plates 31, the fitting blocks 5 and 6, and the closure plate 4) together with braze alloy appropriately placed on surfaces of the components that are to be joined. The braze alloy can be provided as a clad layer on one or more the components, or can be applied as a foil or a paste, or some combination of these. End caps 29 can additionally be inserted into the open ends of the manifolds 5 and 6 prior to brazing in order to seal off the manifolds. Once assembled, the assembly 2 can be fixtured and heated in a brazing oven in order to reflow the braze alloy and create the braze joints between the components.

(20) In some especially preferable embodiments, the components that define the brazed assembly 2 are all constructed of a brazeable aluminum alloys. Such a construction advantageously provides a compact and low-weight design. However, in other embodiments the brazed assembly 2 can be constructed of other metals such as titanium, steel, copper, and the like.

(21) Prior to assembly of the brazed assembly 2 and the plastic housing 3, coolant baffles 14 and/or 15 can be assembled to the brazed assembly 2 or to the plastic housing 3. The baffles 14, 15 can be constructed of a variety of materials, including plastic, elastomers, rigid foams, metal, etc. The plastic housing 3 is provided with recessed grooves 25 to receive the baffles and to retain their position once the liquid to refrigerant heat exchanger 1 is fully assembled. In some embodiments, the coolant baffles 14, 15 are provided with circular holes 28 that correspond to the ends of the manifolds 5, 6. The coolant baffles 14, 15 can be assembled to the brazed assembly 2 by insertion of the ends of the manifolds into the holes 28, thereby placing the coolant baffles 14, 15 in the appropriate position prior to the assembly of the plastic housing 3. In other embodiments, the coolant baffles 14, 15 can be inserted into the grooves 25 of the plastic housing 3 prior to the insertion of the brazed assembly 2.

(22) The coolant baffles 14, 15 divide the coolant volume 20 into three portions. A heat exchange portion 20a of the coolant volume 20 is located between the first coolant baffle 14 and the second coolant baffle 15. The refrigerant conduits 7 and the coolant fins 24 are preferable located completely within the heat exchange portion 20a. The coolant baffle 14 separates the heat exchange portion 20a from a coolant inlet portion 20b arranged at the end of the heat exchanger 1 where the coolant inlet port 21 is located, so that the flow of coolant 40 received into the liquid to refrigerant heat exchanger 1 through the coolant inlet port 21 is discharged into the coolant inlet portion 20b. The coolant baffle 15 separates the heat exchange portion 20a from a coolant outlet portion 20c arranged at the end of the heat exchanger 1 where the coolant outlet port 22 is located, so that the flow of coolant 40 removed from the liquid to refrigerant heat exchanger 1 through the coolant outlet port 21 is received from the coolant outlet portion 20c.

(23) The coolant baffles 14, 15 are each provided with an aperture 23 that corresponds to the outer periphery of the assembled coolant fins 24. The flow of coolant is directed and channeled into the coolant fins 24 from the inlet portion 20b of the coolant volume 20 through the aperture 23 of the coolant baffle 14. Similarly, the flow of coolant is discharged into the outlet portion 20c of the coolant volume 20 through the aperture 23 of the coolant baffle 15.

(24) The liquid to refrigerant heat exchanger 1 is assembled by inserting the refrigerant conduits 7, coolant fins 24, and manifolds 5 and 6 of the brazed assembly 2 into the plastic housing 3. An elastomeric seal 27 is arranged within a gasket well 32 that extends along the periphery of the opening of the plastic housing 3 prior to the insertion of the brazed assembly 2. After the brazed assembly 2 is fully inserted, the peripheral flange 17 is crimped over onto the peripheral edge of the plastic housing 3 in order to compress the seal 27 so that leakage of coolant is prevented. Beads 26 can be formed into the closure plate 4 in order to back-stop the gasket well and prevent deformation of the plastic housing 3 during the crimping process.

(25) Various alternatives to the certain features and elements of the present invention are described with reference to specific embodiments of the present invention. With the exception of features, elements, and manners of operation that are mutually exclusive of or are inconsistent with each embodiment described above, it should be noted that the alternative features, elements, and manners of operation described with reference to one particular embodiment are applicable to the other embodiments.

(26) The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention.