The present invention relates to a heat exchanger, and more specifically relates to a suction line heat exchanger for use in climate control systems operating on the vapor compression cycle for cooling a refrigerant.
According to an aspect of the invention, a suction line heat exchanger is provided for transferring heat from a high pressure refrigerant traveling along a first flow path to a low pressure refrigerant traveling along a second flow path. The suction line heat exchanger includes a first mounting surface having a first refrigerant inlet port located along the first flow path and a first refrigerant outlet port located along the second flow path, and further includes a second mounting surface having a second refrigerant inlet port located along the second flow path and a second refrigerant outlet port located along the first flow path. The suction line heat exchanger further includes a first plurality of flow channels fluidly connected to the first refrigerant inlet port to receive the high pressure refrigerant therefrom and fluidly connected to the second refrigerant outlet port to deliver the refrigerant thereto, and a second plurality of flow channels fluidly connected to the second refrigerant inlet port to receive the low pressure refrigerant therefrom and fluidly connected to the first refrigerant outlet port to deliver the refrigerant thereto, the first and second plurality of flow channels being in heat transfer relation with one another.
In some embodiments, the first plurality of flow channels are interleaved with the second plurality of flow channels, with adjacent first and second flow channels being separated from one another by a plurality of essentially planar thermally conductive plates.
In some embodiments a plurality of fin structures are arranged along the first and second plurality of flow channels and are bonded to the thermally conductive plates to provide structural support and increased surface area for heat transfer between the refrigerant flows in adjacent channels.
In some embodiments the suction line heat exchanger includes a fastening means to sealingly attach a first set of refrigerant lines to the first mounting surface, the first set of refrigerant lines comprising a liquid line configured to deliver a high pressure subcooled liquid refrigerant from a condenser to the first refrigerant inlet port and further comprising a suction line configured to deliver a low pressure superheated refrigerant flow from the first refrigerant outlet port to a compressor.
In some embodiments the suction line heat exchanger includes a fastening means to sealingly attach the second mounting surface to a port block comprising a first port configured to receive a pressurized subcooled liquid refrigerant from the second refrigerant outlet port of the suction line heat exchanger and further comprising a second port configured to deliver a low pressure refrigerant flow to the second refrigerant inlet port of the suction line heat exchanger. In some embodiments the port block may comprise an expansion device to expand the pressurized subcooled liquid refrigerant. In some embodiments the port block may comprise both an expansion device to expand the pressurized subcooled liquid refrigerant and a sensing device sensitive to the level of superheat in the low pressure refrigerant flow and configured to adjust the pressure drop in the expansion device in response to said level of superheat.
In one embodiment of the invention a suction line heat exchanger is configured to be installed into a vehicular vapor compression based climate control system comprising a first flow path to deliver a high pressure subcooled refrigerant from a condenser to a port block mounted on a firewall of the vehicle, further comprising a second flow path to deliver a low pressure superheated refrigerant flow from said port block to a compressor, further comprising a third flow path from said port block to an expansion device to receive the high pressure subcooled refrigerant from the port block, and further comprising a fourth flow path from an evaporator to said port block to deliver the low pressure superheated refrigerant flow to the port block, where the first and second flow paths are located on a common side of the firewall and the third and fourth flow paths are located on the opposing side of the firewall. In a further aspect the suction line heat exchanger is configured to mount directly to the port block mounted on the vehicle firewall in order to receive the refrigerant traveling along the first flow path from the condenser and deliver it to the port block, to receive the refrigerant traveling along the second flow path from the port block and deliver it to the compressor along the second flow path, and to transfer heat from the first flow path refrigerant to the second flow path refrigerant.
In another embodiment of the invention a suction line heat exchanger is configured to be installed into a vehicular vapor compression based climate control system comprising a first flow path to deliver a high pressure subcooled refrigerant from a condenser to an expansion valve mounted on a firewall of the vehicle, further comprising a second flow path to deliver a low pressure superheated refrigerant flow from said expansion valve to a compressor, further comprising a third flow path from said expansion valve to an evaporator to deliver the refrigerant from the first flow path as a low pressure liquid/vapor refrigerant to the evaporator, and further comprising a fourth flow path from said evaporator to said expansion valve to deliver the low pressure superheated refrigerant flow to the expansion valve, where the first and second flow paths are located on a common side of the firewall and the third and fourth flow paths are located on the opposing side of the firewall. In a further aspect the suction line heat exchanger is configured to mount directly to the expansion valve mounted on the vehicle firewall in order to receive the refrigerant traveling along the first flow path from the condenser and deliver it to the expansion valve, to receive the refrigerant traveling along the second flow path from the expansion valve and deliver it to the compressor along the second flow path, and to transfer heat from the first flow path refrigerant to the second flow path refrigerant.
Other features, aspects, objects and advantages of the invention will become apparent from a complete reading of the specification and drawings.
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 following 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.
With reference to
In some systems, the expansion device 8 may take the form of a simple fixed orifice. In other systems, the expansion device may take the form of a variable orifice size valve, the orifice size being adjusted in response to the temperature of the refrigerant 12 downstream of the evaporator 5, said temperature being determined by a sensing device 9. In some such systems the expansion valve 8 and sensing device 9 comprise an expansion assembly 7, typically referred to as a thermostatic expansion valve or TXV.
The climate control system 1 is additionally shown to include an optional heat exchanger 10, sometimes referred to as an internal heat exchanger (IHX) or suction line heat exchanger (SLHX), to transfer heat from the refrigerant 12 downstream of the condenser 3 and upstream of the expansion device 8 to the refrigerant 12 downstream of the evaporator 5 and upstream of the compressor 2. While such a suction line heat exchanger is not required for the climate control system 1 to operate, the inclusion of it will provide certain benefits to the overall system operation.
Some of the aforementioned benefits derived from the inclusion of the SLHX 10 will now be described with reference made to
Referring now to
Turning now to
As an additional benefit, the SLHX 10 will ensure that the refrigerant 12 entering the compressor 2 will be fully vaporized to a vapor state. The introduction of refrigerant into a compressor with some fraction of the refrigerant remaining in an unvaporized liquid state can cause damage to the compressor, and is therefore highly undesirable. In typical systems lacking a suction line heat exchanger, this is avoided by operating the system to deliver a greater level of superheat at the exit of the evaporator, thereby ensuring that complete vaporization of the refrigerant will occur in the evaporator. Such operation will, however, result in a decrease in system performance in certain operating conditions. In contrast, the SLHX is able to eliminate the possibility of liquid refrigerant entering the compressor by providing efficient heat transfer between the refrigerant upstream of the compressor and the hot refrigerant upstream of the expansion device. This allows the system to be operated with a low superheat setting without compromising performance, thereby improving the overall efficiency of the system.
As yet another benefit, the inclusion of a SLHX can enable the system 1 to operate with a smaller compressor 2. In a typical mobile air conditioning application, the system is designed to enable a rapid cooling of a hot vehicle interior in high ambient conditions, such as when the vehicle is started after sitting for some time on a hot day. The requirement for achieving this rapid cooling, referred to as “pull-down”, sets the required cooling capacity of the system, and consequently determines the required compressor size. However, for the majority of the time that the system is operating, the required cooling capacity will be much less than the required pull-down cooling capacity, as the system will be operating so as to maintain an already achieved cool vehicle interior temperature. As a result, the compressor 2 will most often be operating at a reduced capacity, which results in very inefficient compressor operation. The system performance improvement resulting from including the SLHX 10 into the system 1 can enable a smaller compressor 2 without sacrificing pull-down performance. Operating with a smaller compressor will increase the compressor efficiency at the reduced operating conditions that the cooling system operates at for the majority of the time, thereby again serving to increase the overall efficiency of the system.
In light of the foregoing, it should be appreciated that a climate control system 1 that does not have a suction line heat exchanger 10 would be able to derive benefit from the inclusion of such a heat exchanger. Accordingly, an embodiment of a suction line heat exchanger that is highly suited for inclusion into a climate control system will now be described, with reference made to
The embodiment of the SLHX 10 shown in
The embodiment of
The embodiment of
Continuing with the embodiment of
Each of the plates 22 further includes another embossment 53 to locally raise the surface 41, and each of the plates 23 further includes another embossment 59 to locally raise the surface 40. The surface 41 of an embossment 53 mates against the surface 40 of an embossment 59 to form a sealed joint. The embossment 53 defines an opening 56 and the embossment 59 defines a corresponding opening 62, the plurality of openings 56 and 62 comprising a second internal manifold 31 in fluid communication with the plurality of spaces 25. The internal manifold 31 is additionally in fluid communication with the outlet port 18 by way of a second external conduit 30 formed into a cap plate 38, the inlet port 19 and outlet port 18 thereby being in fluid communication with one another.
Each of the plates 22 further includes an embossment 52 to locally raise the surface 42, and each of the plates 23 includes an embossment 58 to locally raise the surface 39. The surface 42 of an embossment 52 mates against the surface 39 of an embossment 58 to form a sealed joint. The embossment 52 defines an opening 57 and the embossment 58 defines a corresponding opening 63, the plurality of openings 57 and 63 comprising a third internal manifold 33 in fluid communication with the plurality of spaces 24. The internal manifold 33 is additionally in fluid communication with the inlet port 17 by way of a third external conduit 32 formed into the cap plate 38, so that the plurality of spaces 24 comprise a plurality of flow channels for a refrigerant traveling on the first refrigerant flow path 13.
Each of the plates 22 further includes another embossment 46 to locally raise the surface 42, and each of the plates 23 further includes another embossment 45 to locally raise the surface 39. The surface 42 of an embossment 46 mates against the surface 39 of an embossment 45 to form a sealed joint. The embossment 46 defines an opening 55 and the embossment 45 defines a corresponding opening 61, the plurality of openings 55 and 61 comprising a fourth internal manifold 26 in fluid communication with the plurality of spaces 24. The internal manifold 26 is additionally in fluid communication with the outlet port 20 by way of a fourth external conduit 27 formed into the cap plate 37, the inlet port 17 and outlet port 20 thereby being in fluid communication with one another.
Each of the plates 23 further includes another embossment 90 to locally raise the surface 40, and another embossment 64 located within the perimeter of the embossment 90, the embossment 64 extending in the direction opposite the embossment 90 to locally raise the surface 39, the depth of the embossment 64 being greater than the depth of the embossment 90. Each of the plates 22 further includes another embossment 47 to locally raise the surface 42, the surface 42 of an embossment 47 mating against the surface 39 of an embossment 64 to form a sealed joint. The raised surface 40 of each embossment 90 mates against the surface 41 of the adjacent plate 22 to likewise form a sealed joint. The embossment 47 defines an opening 48 and the embossment 64 defines a corresponding opening 49, the plurality of openings 48 and 49 forming an open volume 36 extending through the heat exchanger core region 21. The open volume 36 is sealed off from the flow channels 24 by the seal formed at the embossments 90, and is sealed off from the flow channels 25 by the seal formed at the embossments 46 and 47. Alternate ways to create the open volume 36, such as with flanges similar to the flanged perimeters 50, 51 surrounding holes 48 and 49 to form a seal, have also been contemplated by the inventors.
As best seen in
Although not shown in the accompanying figures, in some embodiments the SLHX 10 can include extended surface area features in the flow channels 24 and/or in the flow channels 25, in order to provide both improved heat transfer and structural support of the plates. Such extended surface features may comprise a plurality of convoluted fin structures, such as for example lanced and offset fins, with the fin structures relieved in the areas corresponding to the embossments on the plates 22 and 23.
Turning now to
As best seen in the exploded view of
In the embodiment depicted in
In some embodiments the heat exchanger module may provide certain advantages for a climate control system 1 on a motor vehicle such as, by way of example only, an automobile or a commercial truck. Such a vehicle may typically include a firewall 93 separating an engine compartment of the vehicle from a passenger cabin of the vehicle. Oftentimes select portions of the climate control system 1 will be located on the engine compartment side of the firewall 93, such as, for example, the compressor 2 and condenser 3. The evaporator 5 will, however, typically be located on the passenger cabin side of the firewall 93 to facilitate the movement of air cooled by the evaporator 5 throughout the passenger cabin, thus requiring some of the fluid lines carrying the refrigerant 12 through the climate control system 1 to pass through the firewall 93.
As illustrated in
The embodiment shown in
An alternate embodiment of the heat exchanger module 91 is shown in
An additional embodiment of a SLHX 10 for use in a heat exchanger module 91 is illustrated in
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.
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.
This application claims priority to Provisional Patent Application No. 61/163,506, filed Mar. 26, 2009, the entirety of which is incorporated herein by reference.
Number | Date | Country | |
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61163506 | Mar 2009 | US |