Patent ID: 12253287

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description and appended drawings describe and illustrate various embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical.

A″ and “an” as used herein indicate “at least one” of the item is present; a plurality of such items may be present, when possible. Spatially relative terms, such as “front,” “back,” “inner,” “outer,” “bottom,” “top,” “horizontal,” “vertical,” “upper,” “lower,” “side,” “above,” “below,” “beneath,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

As used herein, substantially is defined as “to a considerable degree” or “proximate” or as otherwise understood by one ordinarily skilled in the art or as otherwise noted. Except where otherwise expressly indicated, all numerical quantities in this description are to be understood as modified by the word “about” and all geometric and spatial descriptors are to be understood as modified by the word “substantially” in describing the broadest scope of the technology. “About” when applied to numerical values indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by “about” and/or “substantially” is not otherwise understood in the art with this ordinary meaning, then “about” and/or “substantially” as used herein indicates at least variations that may arise from ordinary methods of measuring or using such parameters.

Where any conflict or ambiguity may exist between a document incorporated by reference and this detailed description, the present detailed description controls. Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section, depending on the context or circumstance.

FIG.1illustrates a refrigerant circuit10having an integrated receiver, drier, and economizer (RDE)40according to an embodiment of the present invention. The refrigerant circuit10may form a portion of a thermal management system of a vehicle. The vehicle may be a hybrid or electric vehicle relying upon stored electrical power to provide heat to various components of the vehicle as well as the air to be delivered to the passenger cabin of the vehicle via the operation of the thermal management system and the corresponding refrigerant circuit10, although the present invention is not necessarily limited to use in such a vehicle.

The refrigerant circuit10includes a primary circuit11having at least a compressor12, a condenser13, the RDE40, an expansion element14, and an evaporator15. The primary circuit10may also include an internal heat exchanger18, a secondary expansion element20, and a chiller22. The refrigerant circuit10is shown in substantially simplified schematic form inFIG.1and may include additional flow paths, valves, and/or components from those illustrated without necessarily departing from the scope of the present invention, so long as the same relationships are present within the refrigerant circuit10for prescribing operation thereof in the manner described hereinafter, and especially with regards to the operation of the disclosed RDE40and associated components thereof.

The compressor12is a vapor injection compressor having a vapor injection capability wherein refrigerant is selectively returned to the compressor and injected into a compression chamber of the compressor. The returned refrigerant is injected as a gaseous vapor at an intermediate pressure between a suction pressure and a discharge pressure of the corresponding compressor for increasing the pressure of the refrigerant contained within the compression chamber. The compressor12is generally configured to increase a pressure and temperature of the refrigerant while in a gaseous state. The vapor injection compressor may be a vapor injection scroll compressor having variable compression chambers formed between a fixed scroll and an orbiting scroll, wherein an orbiting of the orbiting scroll relative to the fixed scroll results in a radial inward reduction in volume of each of the compression chambers. Each of the compression chambers may receive the refrigerant at the suction pressure at one or more inlets disposed at a radial outer portion of the fixed scroll and may discharge the refrigerant at the discharge pressure at an outlet disposed at a radial center of the fixed scroll, and each of the injection ports utilized in injecting the vapor into the compression chambers may be disposed radially intermediate the inlet(s) and the outlet. One-way valves may be utilized at each injection port to ensure that the refrigerant is only injected into the compression chambers when the refrigerant is at a pressure higher than that instantaneously within the compression chamber as the shape and position of the compression chamber changes while moving radially inwardly, thereby ensuring that the injection process results in an increase in the pressure of the refrigerant in the compression chamber into which the vapor is injected. However, any form of compressor utilizing such injection of the refrigerant in a gaseous form and at a pressure intermediate the suction pressure and the discharge pressure of the associated compressor may be utilized in conjunction with the present invention without departing from a scope of the present invention.

The condenser13is a heat exchanger configured to remove heat from the high temperature and high pressure refrigerant exiting the compressor12. The refrigerant exiting the condenser13may be partially liquid and partially gaseous in phase. The condenser13may be in heat exchange communication with any other fluid suitable for removing heat from the refrigerant within the condenser13. In some embodiments, the condenser13may be a water-cooled condenser (WCC) in fluid communication with a liquid coolant of an associated fluid system of the vehicle, such as a coolant system utilized in cooling various components of the vehicle. In other embodiments, the condenser13may be a radiator configured to exchange heat with ambient air. In still other embodiments, the condenser13may be a heating heat exchanger disposed within an HVAC casing (not shown) of the vehicle, and may be configured to heat air delivered to a passenger compartment of the vehicle.

The RDE40includes a tank42having a hollow interior43into which the refrigerant exiting the condenser13flows as the two-phase liquid and gaseous form. The refrigerant of the primary circuit is in fluid communication with the hollow interior43of the tank42via each of a dispensing conduit44and a pick-up conduit45. The tank42is arranged to include an axial direction thereof arranged parallel to the direction of gravity to cause the liquid phase of the refrigerant to fall downward from the dispensing conduit44to accumulate at a bottom portion of the tank42, wherein an end of the dispensing conduit44may be positioned and oriented to cause the refrigerant to enter the tank42at or adjacent an upper end of the hollow interior43. In some embodiments, the dispensing conduit44may be provided as an opening51formed within a cap50utilized to delimit the hollow interior43with respect to the upward vertical direction, wherein the opening51formed within the cap50opens into the hollow interior43. Such a configuration is shown inFIG.2. In other embodiments, the dispensing conduit44may be a pipe that depends downwardly from the opening51formed in the cap50to include a distal end of the dispensing conduit44within the hollow interior43, as shown schematically inFIG.1. The distal end of the dispensing conduit44may be arranged at an angle relative to the axial direction of the tank42to promote the liquid refrigerant falling at an angle for reaching a desired position within the tank42. The pick-up conduit45depends downwardly from a corresponding opening52formed in the cap50to ensure fluid communication with the liquid refrigerant disposed within the tank42. Each of the described openings51,52formed within the cap50may be associated with any necessary structure such as suitable fluid couplings or fluid fittings associated with fluidly coupling an associated fluid line to each of the described conduits44,45. For example, a block type seal fitting may be utilized at each junction of one of the external fluid lines with the cap50to prevent leakage of the refrigerant where the primary circuit11passes through the RDE40.

As shown in each ofFIGS.1and3, the accumulation of the liquid refrigerant within the tank42causes the hollow interior43to be divided axially into a liquid containing portion43aoccupied by the liquid refrigerant at the lower end of the hollow interior43and a gas containing portion43boccupied by the gaseous refrigerant at a position above the liquid containing portion43aand towards the upper end of the hollow interior43. The pick-up conduit45includes an inlet end46that is disposed to be submerged within the liquid containing portion43aof the hollow interior43adjacent the lower end thereof to cause the liquid phase of the refrigerant contained within the tank42to flow towards the downstream arranged expansion element14and evaporator15via the pick-up conduit45.

The division of the hollow interior43into the liquid containing portion43aand the gas containing portion43bmay vary during operation of the refrigerant circuit10as different operating modes are utilized requiring different quantities of the refrigerant circulating through the refrigerant circuit10. Specifically, when demands are relatively low, the level of the liquid refrigerant forming the liquid containing portion43amay be relatively high and towards the cap50of the tank42. In contrast, when demands are relatively high, the level of the refrigerant lowers to a level closer to an upper surface of a heating exchanging structure of the economizer70, although the heat exchanging structure of the economizer70also remains submerged within the liquid containing portion43aregardless of the selected operating mode. The refrigerant circuit10may include the necessary amount of refrigerant to maintain the liquid refrigerant at desirable levels within the tank42in accordance with all such operating modes. Additionally, the refrigerant circuit10may include an additional supply of refrigerant constituting a charge reserve of the liquid refrigerant stored within the tank42, wherein such a charge reserve of the liquid refrigerant refers to an amount of the liquid refrigerant supplied for replacing any liquid refrigerant incidentally exiting the refrigerant circuit10during use thereof. Additional features of the RDE40are described in detail hereinafter when describing an economizer70integrated into the RDE40and forming a portion of a vapor injection branch pathway25branching from the primary circuit11downstream of the condenser13.

The expansion element14may refer to any structure or device for contracting and then expanding a flow of the refrigerant therethrough such that a temperature and a pressure of the refrigerant are each lowered following passage through the expansion element14. The expansion element14is accordingly configured to lower a temperature and a pressure of the refrigerant passing therethrough prior to entry into the evaporator15and following passage through the tank42of the RDE40via the dispensing and pick-up conduits44,45. The expansion element14may be referred to as the primary expansion element by virtue of its placement on the primary circuit11.

The expansion element14may be a fixed orifice or may be an adjustable expansion device wherein a flow cross-section through the expansion element14may be varied to alter the drop in pressure and temperature of the refrigerant passing therethrough. In some embodiments, the expansion element14may be further associated with a shut-off valve (not shown) or may be adjustable to a fully closed position wherein refrigerant cannot pass therethrough, thereby preventing the flow of the refrigerant through the downstream arranged evaporator15. If provided as an adjustable expansion device, the expansion element14may be an electronic expansion valve (EXV) where the flow cross-section through the expansion element14is electronically controlled according to an associated control scheme, which may include being adjusted to a fully closed position. The expansion element14may alternatively be provided as a thermal expansion valve (TXV) where a temperature of the refrigerant encountering the TXV controls a flow cross-section through the TXV, such as increasing or decreasing the flow cross-section in reaction to an increasing or decreasing temperature of the refrigerant, as the circumstances may warrant. The TXV may also be configured to be adjustable to fully close off flow therethrough, as conditions may warrant based on the configuration of the TXV and the operating parameters thereof.

The evaporator15is a heat exchanger configured to add heat to the high temperature and high pressure refrigerant entering the compressor12with the refrigerant exiting the evaporator15being gaseous in phase. The evaporator15may be in heat exchange communication with any other fluid suitable for removing heat from the refrigerant within the evaporator15. In some embodiments, the evaporator15may be a cooling heat exchanger disposed within the HVAC casing (not shown) of the vehicle, and may be configured to cool and/or dehumidify air delivered to a passenger compartment of the vehicle. In other embodiments, the evaporator15may be configured to cool a fluid or structural component associated with operation of the vehicle, and may alternatively be referred to as a chiller in such circumstances.

The secondary expansion element20and the chiller22may be disposed in a parallel flow configuration relative to the expansion element14and the evaporator15such that the refrigerant may flow through the expansion element14and the evaporator15and/or the secondary expansion element20and the chiller22, depending on the desired operation of the refrigerant circuit10. It should accordingly be understood that references hereinafter to a flow of the refrigerant through the expansion element14and the evaporator15may alternatively refer to the refrigerant being distributed to flow through each of the evaporator15via the expansion element14and the chiller22via the secondary expansion20, or may refer to the refrigerant being exclusively distributed to flow through the chiller22via the secondary expansion element20absent flow through the evaporator15, without necessarily departing from the scope of the present invention. It should also be understood that components being described as upstream or downstream of the expansion element14and the evaporator15are also similarly disposed upstream or downstream of the secondary expansion element20and the chiller22in the same manner.

In some embodiments, the primary circuit11may include the branching of the refrigerant to three or more of the evaporators/chillers at the disclosed position, as necessary, to prescribe the desired cooling to each component or fluid of an associated system. For example, the additional branches of the primary circuit may each be associated with a chiller directly or indirectly (via an intervening fluid) cooling a different electronic component of the vehicle. In other embodiments, the refrigerant circuit10may include only the expansion element14and the evaporator15, as desired, in the absence of any form of branching at the illustrated position on the primary circuit11. The secondary expansion element20and any other expansion element associated with any additional chillers and/or evaporators branching from the primary circuit may be provided as any of the examples given with respect to the expansion element14, including being a fixed orifice, an EXV, or a TXV, as non-limiting examples.

The internal heat exchanger18is configured to provide heat exchange communication between a high pressure portion of the refrigerant at a position upstream of the expansion member14and the evaporator15and a low pressure portion of the refrigerant at a position downstream of the expansion member14and evaporator15. The high pressure portion of the refrigerant has a relatively greater temperature than the low pressure portion of the refrigerant at the internal heat exchanger18, hence the heat exchange occurring via the internal heat exchanger18causes a temperature of the high pressure portion of the refrigerant to be decreased and also causes a temperature of the low pressure portion of the refrigerant to be increased. The decreasing of the temperature of the high pressure portion of the refrigerant leads to a subcooling of the high pressure portion of the refrigerant below the saturation temperature thereof, which in turn leads to a cooling capacity of whichever evaporator15or chiller22is passed by the refrigerant, depending on the desired operating mode of the refrigerant circuit10, being increased via the heat exchange occurring within the internal heat exchanger18in comparison to a refrigerant circuit devoid of such heat exchange. The low pressure portion of the refrigerant may also be superheated to a temperature above the evaporation temperature of the refrigerant via the heat exchange occurring within the internal heat exchanger18.

The vapor injection branch pathway25branches from the primary circuit11at a branch point26disposed downstream of the condenser13and upstream of the tank42of the RDE40. In the present embodiment, the branch point26is also disposed upstream of the internal heat exchanger18on the high-pressure side of the primary circuit. The vapor injection branch pathway25extends from the branch point26to a vapor injection port28of the vapor injection compressor12where the refrigerant flowing along the vapor injection branch pathway25is able to selectively enter a compression chamber of the vapor injection compressor12when exceeding the instantaneous pressure of the refrigerant within the corresponding compression chamber. The branch pathway25includes, in an order of flow therethrough from the branch point26to the vapor injection port28, a branch expansion element29and the economizer70.

The branch expansion element29may be provided as any form of adjustable expansion device having the capability of varying a flow cross-section therethough for varying the extent of the temperature drop and pressure drop experienced by the refrigerant passing therethrough. The adjustable expansion device may also be configured to be adjustable to a fully closed position to prevent passage of the refrigerant through the branch pathway25and to the injection port28of the compressor12during periods of time when the benefits of the vapor injection process are not required for desirably operating the refrigerant circuit10, such as when the cooling demands placed on the evaporator15and/or the chiller22are relatively low and not in need of the sub-cooling provided by the economizer70, as explained hereinafter. The branch expansion element29may be a TXV or an EXV as explained previously with respect to the expansion element14. If a TXV is utilized, the TXV may be configured to be opened only when the refrigerant encountering the branch expansion element29is above a threshold temperature, below a threshold temperature value, or within a range of temperature values, as the circumstances may warrant, for ensuring that the vapor injection process occurs only when the characteristics of the refrigerant indicate the need for such a process in order to meet the requirements of the refrigerant circuit10. The TXV may also be configured to vary the cross-sectional flow area through the branch expansion element29based on the temperature of the refrigerant encountering the TXV.

If an EXV is utilized, the EXV may similarly be configured to be variably adjustable such that the EXV is configured to be opened only when the refrigerant encounters a sensor associated with operation of the EXV that determines that the refrigerant is above a threshold temperature, below a threshold temperature value, or within a range of temperature values. The sensor may be disposed adjacent the EXV or may be associated with measuring the temperature of the refrigerant at another location along the refrigerant circuit10, such as measuring the temperature of the refrigerant prior to entry into the expansion element14or the evaporator15. In other circumstances, a control system of the vehicle associated with operation of the components forming the refrigerant circuit10may be configured to open the EXV according to a user selected setting or the like, such as a change in operating mode of the refrigerant circuit10requiring use of the branch pathway25. In either circumstance, it should be understood that the branch pathway25is configured to only be utilized when the vapor injection process is needed for a certain mode of operation able to be achieved via the refrigerant circuit10, such as when it is desired to increase the cooling capacity of the evaporator15in the manner described above. It should accordingly be understood that the disclosed refrigerant circuit10is operable in the absence of the passage of the refrigerant along the branch pathway25with respect to certain operating modes thereof.

The refrigerant exits the branch expansion element29as a two-phase refrigerant including a gaseous phase and a liquid phase. The economizer70of the integrated RDE40is configured to act as a form of an evaporator of the branch pathway25where the liquid refrigerant entering the economizer70is evaporated therein to result in the refrigerant exiting the economizer70and flowing towards the vapor injection port28of the compressor12as a purely gaseous refrigerant capable of injection into a corresponding compression chamber of the compressor12. The evaporating of the refrigerant within the economizer70occurs via a transfer of heat from the relatively hot liquid refrigerant forming the liquid containing portion43aof the tank42exterior to the economizer70to the relatively cooler two-phase refrigerant passing through the interior of the economizer70. This transfer of heat results in a decrease in temperature of the liquid refrigerant within the tank42, thereby causing a reduction in temperature of the liquid refrigerant exiting the liquid containing portion43avia the pick-up conduit45for flow downstream to the expansion element14and the evaporator15. The economizer70accordingly facilitates a subcooling of the liquid refrigerant exiting the liquid containing portion43aof the tank42below the saturation temperature of the corresponding refrigerant for increasing the cooling capacity of the downstream arranged evaporator15and/or chiller22. The gaseous refrigerant exiting the economizer70may also be superheated beyond the evaporation temperature of the corresponding refrigerant before entering the injection port28of the compressor12. The economizer70accordingly operates in similar fashion to the internal heat exchanger18during use of the vapor injection process by cooling a relatively high pressure liquid phase of the refrigerant prior to the refrigerant flowing downstream and encountering the expansion element14and the evaporator15, thereby increasing a cooling capacity of the evaporator15(and/or the chiller22or any other parallel arranged evaporator/chiller) in comparison to a circuit devoid of such additional subcooling.

Referring now more specifically toFIGS.2-4, a structure of an exemplary economizer70suitable for use with the refrigerant circuit10is disclosed. The economizer70is provided as a plate-type heat exchanger having a repeating and alternating arrangement of stacked plates72. Each of the plates72is configured to extend substantially perpendicular to the axial direction of the tank42when the plates72are stacked therein. A thickness of each of the plates72, which extends primarily in the axial direction of the tank42, is exceeded by the remaining dimensions of each of the plates72in directions arranged perpendicular to the axial direction.

As best shown inFIGS.3and4, each of the plates72includes a first major surface73and an opposing second major surface74. The first major surface73may be considered an outer or exterior surface of each of the plates72configured to encounter the liquid refrigerant disposed within the liquid containing portion43aof the tank42and flowing around an exterior of the economizer70while the second major surface74may be considered an inner or interior surface of each of the plates72configured to encounter the gaseous or two-phase refrigerant flowing within the interior of the economizer70.

Each of the plates72includes a planar portion81, a first axial extension portion82, a first contact portion83, a second axial extension portion84, a second contact portion85, a third axial extension portion86, and a third contact portion87. The planar portion81extends along a plane that is arranged perpendicular to the axial direction of the tank42and occupies a majority of each of the major surfaces73,74of each of the plates72. The first axial extension portion82and the second axial extension portion84are spaced apart from each other with respect to a direction perpendicular to the axial direction of the tank42and are disposed within a periphery of the planar portion81. The first axial extension portion82and the second axial extension portion84each extend a common distance axially away from the planar portion81with respect to a first axial direction of the tank42.

The first axial extension portion82is annular in shape and surrounds the first contact portion83and the second axial extension portion84is also annular in shape and surrounds the second contact portion85. The first contact portion83and the second contact portion85are each planar in configuration and are disposed on a common plane that is spaced apart from the plane of the planar portion81by the common axial extension of each of the first and second axial extension portions82,84. The first contact portion83surrounds a first manifold opening88formed through the plate72while the second contact portion85surrounds a second manifold opening89formed through the plate72.

The third axial extension portion86is formed adjacent a periphery of each of the plates72and extends to surround the planar portion81thereof. The third axial extension portion86extends a distance axially away from the planar portion81with respect to a second axial direction of the tank42arranged opposite the first axial direction thereof. The distance of axial extension of the third axial extension portion86may be the same as the common distance of axial extension of each of the axial extension portions82,84, although alternative configurations may be utilized, including different distances of axial extension between the portions82,84and the portion86. The third contact portion87is formed around a periphery of the third axial extension portion86, hence the third contact portion87surrounds each of the third axial extension portion86and the planar portion81. The third contact portion87is disposed on a plane arranged perpendicular to the axial direction of the tank42, and is thus arranged perpendicular to the planar portion81and each of the remaining contact portions83,85.

The third contact portion87is shown as further including an axially extending rim88extending from select segments of the periphery thereof. The axially extending rim88may be positioned to contact an inner circumferential surface49of the tank42while extending parallel thereto, thereby increasing a surface area of the plate72at the inner circumferential surface49while also providing an additional flow-guiding surface with respect to certain flow paths formed within the economizer70. However, the third contact portion87may be provided devoid of the rim88, as desired, without departing from the scope of the present invention.

The plurality of plates72forming the economizer70includes a plurality of first plates72aand a plurality of second plates72b, wherein the first plates72aand the second plates72bare stacked in alternating fashion with respect to the axial direction of the tank42. As can be seen inFIGS.3and4, the structure of each of the first plates72ais identical to the structure of each of the second plates72b, but the first plates72ahave a different orientation relative to the second plates72b. Specifically, each of the second plates72bis oriented to be mirrored symmetrically relative to each of the first plates72arelative to a plane that is arranged perpendicular to the axial direction of the tank42. Alternatively, each of the second plates72bmay be said to have an orientation rotated 180 degrees from an orientation of each of the first plates72aabout an axis that is arranged perpendicular to the axial direction of the tank42. In either circumstance, the first plates72aand the second plates72binclude identical features that extend in opposing axial directions of the tank42for forming flow passages both within and around the economizer70as explained hereinafter.

The arrangement of the first plates72arelative to the second plates72bresults in the first major surface73of each of the first plates72afacing towards the first major surface73of a first one of the second plates72bdisposed adjacent the corresponding one of the first plates72atowards a first axial end47of the tank42corresponding to an upper end of the tank42. The disclosed arrangement also results in the second major surface74of each of the first plates72afacing towards the second major surface74of a second one of the second plates72bdisposed adjacent the corresponding one of the first plates72atowards a second axial end48of the tank42corresponding to a lower end of the tank42. With respect to each of the first plates72a, each of the first and second axial extension portions82,84extend axially from the corresponding planar portion81towards the first axial end47while the third axial extension portion86extends axially from the corresponding planar portion81towards the second axial end48. In opposite fashion with respect to each of the second plates72b, each of the first and second axial extension portions82,84extend axially from the corresponding planar portion81towards the second axial end48while the third axial extension portion86extends axially from the corresponding planar portion81towards the first axial end47. Each of the first and second contact portions83,85of each of the first plates72acontacts and is coupled to the respective first and second contact portions83,85of a first one of the second plates72bdisposed adjacent the corresponding one of the first plates72atowards the first axial end47while the third contact portion87of each of the first plates72acontacts and is coupled to the third contact portion87of a second one of the second plates72bdisposed adjacent the corresponding one of the first plates72atowards the second axial end48. The facing first and second contact portions83,85of each of the pairs of plates72a,72bcontact each other along the first major surface73of each of the corresponding plates72a,72bwhile the facing third contact portions87of each of the pairs of plates72a,72bcontact each other along the second major surface74of each of the corresponding plates72a,72b.

As mentioned above, the first major surfaces73correspond to surfaces encountering the liquid refrigerant at an outer surface of the economizer70while the second major surfaces74correspond to surfaces encountering the gaseous or two-phase refrigerant within an interior of the economizer70. Specifically, a plurality of internal flow passages75are formed within the economizer70with each of the internal flow passages75being defined between the second major surfaces74of the facing and coupled together pairs of the plates72a,72bat positions where the second major surfaces74are axially spaced apart from one another. A plurality of external flow passages76are formed within the liquid containing portion43aof the tank42with each of the external flow passages76defined between the first major surfaces73of the facing and coupled together pairs of the plates72a,72bat positions where the first major surfaces73are axially spaced apart from one another. The external flow passages76may, in some circumstances, also be partially defined by a corresponding segment of the inner circumferential surface49of the tank42defining a periphery of the liquid containing portion43aof the tank42.

As best shown inFIG.3, the arrangement of the plates72a,72balso results in the axial alignment of the corresponding first and second manifold openings88,89such that the economizer70includes an inlet manifold chamber91and an outlet manifold chamber92, each of which extends in an axial direction of the tank42through the interior of the economizer70. Each of the manifold chambers91,92is in fluid communication with each of the internal flow passages75formed within the economizer70. The inlet manifold chamber91is configured to receive the two-phase refrigerant exiting the branch expansion element29of the branch pathway25for distribution to each of the axially spaced apart internal flow passages75while the outlet manifold chamber92is configured to collect and recombine the refrigerant having passed through each of the internal flow passages75, which is exclusively in a gaseous state once the refrigerant exits the outlet manifold chamber92.

The cap50of the tank42includes an opening53that is axially aligned with the inlet manifold chamber91as well as an opening54that is axially aligned with the outlet manifold chamber92. Each of the openings53,54may be representative of a fluid conveying portion of the cap50associated with connection to one of the external fluid lines forming the branch pathway25. Specifically, the opening53is configured for coupling to the fluid line extending from the branch expansion element29and thus receives the refrigerant passing through the branch pathway25after expansion therein while the opening54is configured for coupling to the fluid line extending from the RDE40towards the vapor injection port28of the compressor12while dispensing the gaseous refrigerant from the interior of the economizer70. Each of the described openings53,54may have any suitable structure for mating with a corresponding fluid fitting, coupling, or the like for establishing a seal at the cap50for each respective refrigerant flow.

An inlet pipe55depends downwardly from the opening53for connection to an upper disposed one of the first plates72a, which is shown as including a modified first contact portion83and first manifold opening88for reception of and coupling to the inlet pipe55. The inlet pipe55provides fluid communication between the opening53and the inlet manifold chamber91. The inlet pipe55may also provide a limited degree of heat exchange between the two-phase refrigerant passing through the inlet pipe55and each of the gaseous refrigerant within the gas containing portion43bof the tank42and liquid refrigerant within the liquid containing portion43aand the tank42, depending on the level of the liquid refrigerant within the tank42. An outlet pipe56also depends downwardly from the opening54for connection to the upper disposed one of the first plates72a, which similarly includes a modified second contact portion85and second manifold opening89for reception of and coupling to the outlet pipe56. The outlet pipe56provides fluid communication between the outlet manifold chamber92and the opening54. The outlet pipe56may also provide a limited degree of heat exchange between the now gaseous refrigerant passing through the outlet pipe56and each of the gaseous refrigerant within the gas containing portion43bof the tank42and liquid refrigerant within the liquid containing portion43aand the tank42, depending on the level of the liquid refrigerant within the tank42.

A lower disposed one of the plates72, which is shown as one of the first plates72ainFIG.3, may also be modified to include the removal of the corresponding first and second manifold openings88,89from the respective first and second contact portions83,85thereof, thereby delimiting each of the inlet manifold chamber91and the outlet manifold chamber92with respect to the axial direction towards the lower arranged second axial end48of the tank42. However, the disclosed first plate72amay alternatively be replaced with a corresponding second plate72bhaving the same general configuration for delimiting the axial flow of the internally disposed refrigerant, so long as the corresponding contact portions83,85are provided in the absence of the respective manifold openings88,89.

According to the disclosed configuration, the refrigerant passing through the tank42via the primary circuit11and the refrigerant passing through the tank42via the branch pathway25are fluidly segregated from one another throughout passage through the RDE40, including with respect to any flow exterior to and interior to each of the inlet pipe55, the economizer70as formed by the stacked arrangement of the plates72, and the outlet pipe56, hence there is no mixing between the two different flows of the refrigerant within the RDE40.

As best shown inFIGS.2and4, a perimeter shape of each of the stacked plates72determines a 3-dimensional shape of the resulting stacked heat exchanging structure formed by the cooperation of the alternating plates72a,72b. Specifically, each of the plates72includes a substantially circular perimeter shape that has been truncated at each of two diametrically opposing sides. An axis extending between the diametrically opposing sides of the circular shape may be arranged perpendicular to an axis that is itself arranged perpendicular to the axial direction of the tank42and extending between the inlet manifold conduit91and the outlet manifold conduit92. In other words, a direction of spacing between the first truncated portion77of each of the plates72and the opposing second truncated portion78of each of the respective plates72may be arranged perpendicular to a direction of spacing between the inlet manifold chamber91and the outlet manifold chamber92.

Each of the truncated portions77,78refers to a portion of the otherwise circular peripheral shape of each of the plates72that has been indented inwardly from the circular peripheral shape to provide an open space between the periphery of the corresponding plate72and the inner circumferential surface49of the tank42, wherein the circularly shaped portions of the periphery of each of the plates72are dimensioned to otherwise correspond to and fit to the inner circumferential surface49of the tank42for preventing axial flow around the plates72at those positions devoid of one of the truncated portions77,78. The inclusion of each of the truncated portions77,78accordingly forms an open space to each of two diametrically opposing sides of each of the plates72through which the liquid refrigerant comprising the liquid containing portion43aof the tank42is able to flow axially along the length of the economizer70, as explained in greater detail hereinafter.

The first truncated portion77is formed by an edge61of each of the plates72extending rectilinearly in parallel to the direction of spacing between the first and second manifold chambers91,92. The edge61is spaced apart from the inner circumferential surface49of the tank42in a manner forming an opening having a peripheral shape of a segment of a circle between the edge61and the inner circumferential surface49. The second truncated portion78is formed by an edge62comprising a first outer segment63, a center segment64, and a second outer segment65. The first outer segment63and the second outer segment65of the edge61are aligned with each other and extend rectilinearly in parallel to the direction of spacing between the inlet and outlet manifold chambers91,92while the center segment64is semi-circular in shape and is indented towards a center of each of the plates72from the adjacent and straddling outer segments63,65. The center segment64may be inwardly indented to accommodate passage of the pick-up conduit45through the economizer70without intruding into the space formed between the aligned outer segments63,65and the inner circumferential surface49of the tank42, wherein such a space once again has the peripheral shape of a segment of a circle. In other embodiments, the edge62may be entirely rectilinear in extension in the absence of the center segment64, wherein the pick-up conduit45may be disposed entirely within the open space having the shape of a segment of a circle. The spaces formed by the truncated portions77,78are not necessarily limited to the shape of a segment of a circle, as substantially any shape indented from the circular inner circumferential surface49of the cylindrically shaped tank42may be utilized, including an arcuate shape (such as semi-circular), rectangular shape, or trapezoidal shape, each of which is indented inwardly towards a center of each of the plates72. Any shape of the edges61,62forming a space for axial flow of the liquid refrigerant between the inner circumferential surface49and the economizer70may be utilized while remaining within the scope of the present invention.

With respect to the disclosed configuration, each of the plates72includes a peripheral shape including a first circular arc conforming to a first segment of the inner circumferential surface49of the tank42, a first rectilinear line corresponding to the edge61that extends from an end of the first circular arc, a second circular arc conforming to a second segment of the inner circumferential surface49of the tank42that extends from an end of the first rectilinear line, a second rectilinear line corresponding to the first outer segment63of the edge62that extends from an end of the second circular arc, a semi-circular arc corresponding to the center segment64of the edge62that extends from the second rectilinear line, and a third rectilinear line corresponding to the second outer segment65of the edge62that extends from an end of the center segment64for connection to the first circular arc. The described peripheral shape is also shared by a shape of the third contact portion87, the inwardly disposed third axial extension portion86, and a peripheral shape of the inwardly disposed planar portion81of each of the plates72.

The axial stacking of the plates72in the manner previously described results in the heat exchanging structure including the alternating pattern of internal flow passages75and external flow passages76having a truncated cylindrical shape that is truncated at each of two diametrically opposing sides thereof, as formed by the alignment of the stacked first truncated portions77and stacked second truncated portions78of each of the plates72. This results in the formation of a first manifold space101between the inner circumferential surface49of the tank42and the side of the economizer70defined by the cooperating first truncated portions77(corresponding to the edges61) as well as a second manifold space102between the inner circumferential surface49of the tank42and the diametrically opposing side of the economizer defined by the cooperating second truncated portions77(corresponding to the edges62). The first manifold space101may alternatively be referred to as an inlet manifold space while the second manifold space102may alternatively be referred to as an outlet manifold space, by virtue of the direction of flow of the liquid refrigerant within the liquid containing portion43awhen flowing through the economizer70. Each of the manifold spaces101,102may be described as having a shape of a truncated segment of a cylinder, wherein each truncated segment of the cylinder may be formed by a cutting of the corresponding cylindrical shape along a plane arranged parallel to the axial direction of the cylindrical shape and spaced apart from an axis of symmetry of the remainder of the cylindrical shape. The first manifold space101may be disposed directly below the dispensing conduit44of the cap50to promote the separating of the liquid refrigerant entering the tank42by gravity towards the first manifold space101, or the dispensing conduit44may be inclined towards the first manifold space101for creating a desired angle of entry of the liquid refrigerant therein. The second manifold space102includes the pick-up conduit45extending therethrough at the diametrically opposing side of the economizer70from the first manifold space101. The second manifold space102may include the pick-up conduit45extending through the substantially semi-cylindrical space formed by the cooperation of the aligned center segments64of the edges62.

As shown inFIGS.2and3, the economizer70may include a cover plate110that is disposed axially over the upper disposed one of the plates72connected to each of the inlet and outlet pipes55,56towards the first axial end47of the tank42. The cover plate110includes a peripheral shape that is circular with the exception of a single truncated portion111formed by an edge112of the cover plate110disposed to be in axial alignment with the edges61of the underlying stack of plates72, thereby forming a space having the shape of a segment of a circle in axial alignment with the first manifold space101. The cover plate110also includes openings113formed therethrough for reception of the pipes55,56and the conduit45therethrough when the cover plate110is connected to the upper surface of the stack of the plates72. The circular segment of the peripheral shape of the cover plate110is fitted to conform to the inner circumferential surface49of the tank42to prevent the flow of the liquid refrigerant over the top of the economizer70and around the periphery thereof, with the exception of the edge112forming the truncated portion111thereof. The cover plate110is provided to cause any liquid refrigerant disposed above the cover plate110within the liquid containing portion43ato require flow past the edge112and into the first manifold space101rather than bypassing the economizer70via flow directly to the second manifold space102. The cover plate110is shown inFIG.2as having a substantially planar configuration, but in other embodiments the cover plate110may have substantially the same form as one of the first plates72a, including having axially extending portions where each of the pipes55,56or conduits45extends through the cover plate110.

As explained previously, the plates72are joined adjacent each of the aligned edges61of adjacent plates72a,72bsuch that the liquid refrigerant disposed within the first manifold space101is able to be distributed to each of the external flow passages76formed between adjacent sets of the plates72a,72b. The flow of the refrigerant into each of the external flow passages76occurs generally in the direction of spacing of the first manifold space101from the second manifold space102, which is a direction arranged perpendicular to the axial direction of the tank42. The liquid refrigerant exits each of the external flow passages76and enters the second manifold space102while flowing past one of the segments63,64,65of one of the edges62. In the illustrated embodiment, the center segment64includes one of the previously described rims88, hence flow into the second manifold space102may occur primarily past the outer segments63,64of the edge62, which are devoid of such a rim88. In either circumstance, the direction of flow through the external flow passages76occurs with the liquid refrigerant flowing from one of the edges61to a corresponding one of the edges62while flowing from the first manifold space101to the second manifold space102. The described general direction of flow through the internal flow passages75between the manifold chambers91,92occurs in a direction perpendicular to the described general direction of flow through the external flow passages76, hence the flow configuration present between the internal and external flow passages75,76may be said to be a cross-flow configuration.

The heat exchanging structure formed by the stacked plates72may include further heat exchanging structures for increasing a total exposed surface area of the economizer70exposed to the two different flows of the refrigerant encountering the economizer70. As shown inFIGS.3and4, a plurality of corrugated fin elements140may be disposed between adjacent pairs of the plates72a,72bwithin each of the internal and external flow passages75,76for increasing the heat exchanging surface present within each of the flow passages75,76. Each of the fin elements140may contact each of the opposing first major surfaces73of the adjacent disposed pairs of plates72a,72balong the external flow passages76and may also contact each of the opposing second major surfaces74of the adjacent disposed pairs of plates72a,72balong the internal flow passages75. As best shown inFIG.4, the fin elements140may be disposed between the facing sets of major surfaces73,74along the planar portions81of each of the paired plates72a,72b.

Each of the fin elements140includes a plurality of corrugations that are spaced apart from one another with respect to the direction of spacing of the inlet manifold chamber91from the outlet manifold chamber92in a manner wherein a fluid passing through a flow opening formed to either side of one of the corrugations passes in a direction of spacing of the first manifold space101from the second manifold space102. Adjacent ones of the fin elements140are also offset from each other with respect to the direction of spacing of the inlet and outlet manifold chambers91,92to cause each of the flow openings formed to one side of each of the corrugations of each of the fin elements140to be divided into two flow openings formed to each of two opposing sides of the corrugation of a downstream arranged one of the fin elements140. The offset may be a variable offset or may be a fixed and alternating offset, as desired. This arrangement causes a fluid passing through the offset fin configuration to encounter a substantially serpentine flow path with respect to each of the flows encountering the economizer70. Such a serpentine flow path aids in increasing the heat exchange efficiency of the economizer70by encouraging mixing of the refrigerant when recombining after encountering successive fin elements140.

The RDE40further includes a drier separation plate120disposed axially beneath the economizer70. The drier separation plate120is substantially circular in shape and conforms to the inner circumferential surface49of the tank42to prevent axial passage of the refrigerant around a periphery of the drier separation plate120. As shown inFIG.3, the drier separation plate120is spaced apart axially from at least a portion of the lowermost disposed one of the plates72to form a drier distribution chamber122between the lower surface of the lowermost one of the plates72and the drier separation plate120, wherein the drier distribution chamber122is formed within the liquid containing portion43aof the hollow interior43of the tank42. The lowermost disposed one of the plates72may be provided devoid of the corresponding manifold openings88,89therein for preventing the liquid from either of the manifolds91,92from flowing directly into the drier separation chamber122from the interior of the economizer70. The drier distribution chamber122may accordingly be placed in fluid communication with the liquid refrigerant entering the RDE40via the axial flow of the liquid refrigerant through the first manifold space101, wherein the drier distribution chamber122is disposed at the distal end of the first manifold space101. The drier distribution chamber122may also be in fluid communication with the second manifold space102at the diametrically opposing side of the economizer70.

The drier separation plate120forms a partition for separating the drier distribution chamber122from a desiccant chamber124of the hollow interior43of the tank42with respect to the axial direction thereof. The desiccant chamber124is formed within the liquid containing portion43aof the tank42and is disposed towards the lower-disposed second axial end48of the tank42. The desiccant chamber124includes a desiccant126disposed therein. The desiccant126may be representative of any material or structure configured to capture moisture carried by the flow of the liquid refrigerant for drying the flow of the liquid refrigerant. The desiccant126may, for example, be a silica gel provided in bead form (as shown in the figures), or may be a molecular sieve. Any suitable desiccant126may be utilized while remaining within the scope of the present invention.

The drier separation plate120includes a plurality of through-holes121formed therethrough, wherein each of the through-holes121provides fluid communication between the drier distribution chamber122and the desiccant chamber124. During flow of the liquid refrigerant through the economizer70, a portion of the liquid refrigerant flows along the first manifold space101axially before deflecting laterally at the drier separation plate120for lateral flow of the refrigerant through the drier distribution chamber122. At least a portion of the flow of the refrigerant through the drier distribution chamber122flows axially into the desiccant chamber124through one of the through-holes121for interaction with the desiccant126. The liquid refrigerant disposed within the desiccant chamber124eventually flows axially through one of the through-holes121back into the desiccant distribution chamber122. The liquid refrigerant then tends to continue to flow laterally towards the second manifold space102for entry into the inlet end46of the pick-up conduit45.

In some embodiments, the through-holes121may be distributed primarily towards the first manifold space101, such as being formed only in a diametric half of the drier separation plate120towards the first manifold space101, for prescribing a desired flow of the liquid refrigerant into and out of the desiccant chamber124. In other embodiments, the through-holes121may be distributed throughout the entirety of the drier separation plate120, as desired.

The desiccant distribution chamber122may include one of the fin elements140disposed therein to further improve the heat exchanging capacity of the economizer70. The liquid refrigerant also passes over the drier separation plate120in a manner in which the drier separation plate120may also play a role in exchanging heat between the liquid refrigerant and the economizer70. The desiccant distribution chamber122may accordingly be considered to be a lowermost one of the external flow passages76receiving the liquid refrigerant therethrough.

As best shown inFIG.2, a filter130may be disposed within the second manifold space102at a position wherein all flow of the liquid refrigerant exiting the RDE40flows through a screen element131of the filter130immediately prior to entry into the inlet end46of the pick-up conduit45. In the illustrated embodiment, the filter130is constructed with the screen element131having a substantially cylindrical shape extending between the drier separation plate120and the inlet end46of the pick-up conduit45such that the liquid refrigerant passes through the screen element131laterally when flowing from within the second manifold space102and into the interior of the filter130. The liquid refrigerant within the filter130then flows axially towards the inlet end46after debris has been filtered from therefrom via the passage through the screen element131. However, it should be understood that alternative configurations of the filter130may be provided at the inlet end46of the pick-up conduit45without necessarily departing from the scope of the present invention.

In summary, a first flow of the refrigerant associated with the primary circuit11flows into the opening51of the cap50as a two-phase refrigerant. A dispensing conduit44, which may be formed by or may depend from the opening51, directs a liquid phase of the refrigerant to accumulate in the liquid containing portion43aof the tank42while a gaseous phase of the refrigerant collects within the gas containing portion43bthereof. The cover plate110disposed over the top of the economizer70ensures that all liquid refrigerant above the cover plate110is directed to flow axially downwardly through the first (inlet) manifold space101. The liquid refrigerant is then distributed to each of the external flow passages76for passage to the oppositely arranged second (outlet) manifold space102. At least a portion of the liquid refrigerant within the first manifold space101also flows into the drier distribution chamber122for passage into and out of the desiccant chamber124via the through-holes121in the manner described above, wherein the liquid refrigerant interacts with the desiccant126disposed therein to remove any undesirable moisture from the liquid refrigerant. The liquid refrigerant having passed through the external flow passages76proceeds along the second manifold space102towards the inlet end46of the pick-up conduit45, which also includes the removal of debris from the liquid refrigerant via passage through the screen element131of the filter130. The liquid refrigerant exiting the drier distribution chamber122also flows into the second manifold space102and through the filter130to combine with the liquid refrigerant exiting the external flow passages76. The liquid refrigerant then enters the inlet end46of the pick-up conduit45for axial upward flow towards the opening52of the cap50. The liquid refrigerant is then able to proceed downstream to the internal heat exchanger18.

Meanwhile, a second flow of the refrigerant associated with the vapor injection branch pathway25enters the cap50via the opening53and flows axially downwardly towards the economizer70through the inlet pipe55, wherein the second flow of the refrigerant enters the cap50as a two-phase refrigerant. The refrigerant is distributed to the internal flow passages75via the inlet manifold chamber91and is then recombined within the outlet manifold chamber92. The second flow of the refrigerant flows through the internal flow passages75in a direction perpendicular to the direction the first flow of the refrigerant flows through the external flow passages76to form the described cross-flow configuration. The refrigerant flows axially upwardly through the outlet manifold chamber92and then continues to flow axially upwardly out of the economizer70via the outlet pipe56and the corresponding opening54formed in the cap50.

Heat exchange occurs between the first flow of the refrigerant and the second flow of the refrigerant via the economizer70to cool the first flow of the refrigerant and heat the second flow of the refrigerant. The cooling of the first flow of the refrigerant leads to a subcooling of the liquid refrigerant to a temperature below the saturation temperature of the refrigerant while the heating of the second flow of the refrigerant leads to an evaporation of the gaseous phase thereof in addition to superheating of the resulting gaseous refrigerant. The subcooled liquid refrigerant increases a cooling capacity of any downstream-arranged evaporator15or chiller22while the superheated gaseous refrigerant is able to enter the vapor injection compressor12via the downstream-arranged vapor injection port28.

The disclosed vapor injection process may be configured to only occur when the upstream arranged branch expansion element29is opened to allow for the flow of the second flow of the refrigerant through the economizer70. As described above, the opening of the branch expansion element29may occur according to a control scheme executed by a controller and an EXV or may be passively controlled via a temperature sensing mechanism of a TXV to ensure that the vapor injection process occurs only when desired.

In addition to the increased subcooling of the refrigerant for increasing the cooling capacity of the refrigerant circuit10, the disclosed RDE40also provides a significant benefit in reducing the total packaging size and complexity of the RDE40relative to the refrigerant circuit10in comparison to a refrigerant circuit having such components provided independently. This is especially true where the number and orientation of the necessary fluid connections can be reduced to avoid difficult to package components and the like. The use of the RDE40accordingly promotes efficient heat transfer while also facilitating the ability to reorient or repackage components of the associated vehicle in accordance with the recaptured packaging space associated with use of the RDE40.

Referring now toFIGS.5and6, the RDE40may be modified to further include the integration of the branch expansion element29of the vapor injection branch pathway25directly into the structure of the cap50, such as within the described opening53formed within the cap50for communicating the refrigerant to the inlet pipe55.FIG.5illustrates a first modification wherein the branch point26is maintained at a position upstream of the structure of the cap50, thereby resulting in two distinct fluid lines branching from the branch point26for coupling to corresponding openings51,53of the cap50. In contrast,FIG.6illustrates a second modification wherein the branch point26is moved to a position for integration within the structure of the cap50in addition to the integration of the branch expansion element29, thereby resulting in the need for only one fluid line to be coupled to the cap50for feeding each of the two openings51,53disposed downstream of the branch point26. Each of the disclosed modifications beneficially reduces the number of components necessary at positions external to the RDE40, thereby reducing a packaging space of the resulting RDE40while also reducing a number of fluid connections required for coupling the RDE40to the remainder of the refrigerant circuit10.

FIGS.7-9illustrate additional variations to the RDE40that include the integration of an internal heat exchanger into the structure of the tank42of the RDE40. The introduction of the internal heat exchanger into the structure of the RDE40further reduces a packaging size and complexity of the RDE40when installed relative to the remainder of the refrigerant circuit10. The refrigerant circuit10shown in each ofFIGS.7-9operates in identical fashion to the refrigerant circuit10ofFIG.1outside of the modification of the RDE40to include the integration of each disclosed internal heat exchanger, hence further description is omitted herefrom.

FIG.7schematically illustrates the RDE40as including an internal heat exchanger218integrated into an outer surface of the tank42. The RDE40includes a pick-up conduit245extending (radially) outwardly through an outer circumferential wall of the tank42, as opposed to extending axially through the cap50as does the pick-up conduit45ofFIG.1. The pick-up conduit245includes an inlet end246in fluid communication with the liquid containing portion43aof the tank42downstream of the heat exchange occurring within the economizer70. The pick-up conduit245extends radially outwardly beyond the outer circumferential surface of the tank42to expose at least a portion of the pick-up conduit245exterior to the tank42. An internal heat exchanger218is formed where a fluid line251extending from the evaporator15and/or the chiller22intersects the pick-up conduit245for exchanging heat between the high pressure and low pressure flows of the refrigerant at different positions within the primary circuit10.

In one exemplary embodiment, the internal heat exchanger218is formed by a sleeve received over the pick-up pipe245for forming an annular space around the pick-up pipe245configured to receive the low pressure refrigerant exiting the evaporator/chiller15,22via the fluid line251. The sleeve may be directly integrated into the structure of the tank42, and the sleeve may extend radially outwardly from the tank42to surround the pick-up conduit245. The low pressure refrigerant may enter the annular space at a first axial position via the fluid line251before exiting the annular chamber at a spaced apart second axial position via a fluid line252leading to the inlet side of the vapor injection compressor12. The fluid lines251,252may be configured to intersect the annular space at diametrically opposing sides thereof to cause the refrigerant flowing through the annular space to flow both axially and circumferentially when passing between the fluid lines251,252via passage through the internal heat exchanger218. However, the internal heat exchanger218is not limited to such a configuration, as any heat exchanging structure present at the outer surface of the tank42may be utilized for exchanging heat with the liquid refrigerant when exiting the tank42.

FIG.8schematically illustrates the RDE40as including an internal heat exchanger318that is disposed directly within the liquid containing portion43aof the tank42. Specifically, the internal heat exchanger318may be disposed within the second manifold space102formed between the economizer70and the inner circumferential surface49of the tank42adjacent the axial extension of the pick-up conduit45. The internal heat exchanger318is provided as a heat exchanging structure extending between a first port341and a second port342of the tank42. Each of the ports341,342refers to an opening formed through the circumferential wall of the tank42for connection to a first fluid line351and a second fluid line352, respectively. The first fluid line351refers to the fluid line extending from the evaporator/chiller15,22towards the tank42and is configured to be coupled to the first port341while the second fluid line352refers to the fluid line extending from the tank42towards the inlet side of the vapor injection compressor12. In some embodiments, the first and second ports341,342may be spaced apart from each other axially. In other embodiments, the first and second ports341,342may be spaced apart from each other circumferentially, or a combination of axial and circumferential spacing. The heat exchanging structure forming the internal heat exchanger318may have any configuration allowing for the passage of a third flow of the refrigerant through the internal heat exchanger318and between the ports341,342while maintaining a segregation of the liquid refrigerant contained within the liquid containing portion43afrom the gaseous refrigerant passing through an interior of the internal heat exchanger318. The internal heat exchanger318may be formed by a pipe or conduit extending between the ports341,342, wherein the pipe or conduit may include as many turns or bends for providing a desired length of the internal heat exchanger318within the liquid containing portion43a. In other embodiments, the internal heat exchanger318may be formed by a stacked plate-type heat exchanger having a configuration similar to the economizer70, but disposed within the space occupied by the second manifold space102.

FIG.9illustrates the RDE40as having another example of an internal heat exchanger418disposed directly within the liquid containing portion43aof the tank42. The internal heat exchanger418is once again formed by a heat exchanging structure extending from a first port441of the circumferential wall of the tank42to a second port442of the circumferential wall of the tank42, wherein the first port441receives refrigerant from the evaporator/chiller15,22via a fluid line351while the second port442delivers the refrigerant to the inlet side of the vapor injection compressor12via a fluid line452. The internal heat exchanger418differs from the internal heat exchanger318by being stacked below the economizer70as opposed to being disposed laterally relative thereto. The stacked plate-type heat exchanger formed by the internal heat exchanger418may have a configuration that is substantially similar to that of the economizer70as formed by the plates72, except the internal heat exchanger318is configured for delivering the gaseous refrigerant therethrough from the circumferentially disposed first and second ports441,442, as opposed to the axially arranged pipes55,56of the economizer70. The stacked heat exchanging structure may accordingly include the removal of the manifold openings from the structure of each of the plates forming the internal heat exchanger418to instead have the first port441be associated with an inlet manifold for distributing the third flow of the refrigerant to each of the internal flow passages formed through the internal heat exchanger418and the second port442be associated with an outlet manifold for recombining the third flow of the refrigerant. Each of the plates forming the internal heat exchanger418may, for example, include a partition for prescribing a U-shaped flow of the refrigerant therethrough when flowing between the ports441,442, as desired. The internal heat exchanger418may be disposed relative to the first manifold space101and the second manifold space102in similar fashion to the economizer70, and may accordingly prescribe flow of the liquid refrigerant therethrough in substantially similar fashion. The remaining structure of the tank42associated with the drier separation plate120and the desiccant126may be disposed below the internal heat exchanger418in similar fashion to that disclosed relative to the economizer70ofFIGS.2and3.

Each of the embodiments shown throughFIGS.7-9includes the branch expansion element29disposed exterior to the cap50of the tank42, but it should be readily apparent that either of the configurations ofFIGS.5and6may be substituted for any other disclosed embodiment without altering operation thereof, hence such combinations are herein disclosed with respect to the present invention.

Referring now toFIGS.10and11, an alternative configuration of the economizer70may be produced via the utilization of an alternating stack of first plates172aand second plates172baccording to another embodiment of the present invention. The stack of the plates172a,172bis configured for reception within the hollow interior43of the tank42in the same manner as shown with respect to the plates72a,72bofFIGS.2and3and also operates in the same manner except where noted hereinafter. The stack of the plates172a,172bmay be capped at one end by the disclosed cover plate110(or equivalent thereto) and at the other end by the drier separation plate120in the same manner as the plates72a,72b, and accordingly results in the same general flow configuration of the liquid refrigerant over and through the stack of the plates172a,172bas that described with reference to the stack of the plates72a,72b. The plates172a,172b, the cover plate110, and the drier separation plate120may all be fitted to the size and shape of the inner circumferential surface49of the tank42to prevent undesired axial flow of the refrigerant between the different elements172a,172b,110,120for bypassing the described flow configurations. The inlet pipe55, the outlet pipe56, and the pick-up conduit45may all have the same relationships relative to the stack of the plates172a,172bas is disclosed with reference to the stack of the plates72a,72bfor establishing the same flow configurations therethrough.

Each of the plates172a,172bincludes substantially identical structure to each of the corresponding plates72a,72bofFIGS.3and4with the exception of the addition of flow structures185therein, hence identical reference characters are utilized herein in referring to common features present between each of the plates72a,72b,172a,172b. The first plate172ais also substantially identical to the second plate172band configured for symmetric arrangement thereto when placed in a stacked configuration, hence specific description is limited hereinafter to the first plate172aexclusively.

In the illustrated embodiment, each of the flow structures185is formed as an indentation186extending axially into the first major surface73of the associated plate172for forming a corresponding projection187in the opposing second major surface74thereof. The formation of each of the flow structures185into each of the plates172accordingly increases a surface area of each of the plates172in comparison to a plate having a planar configuration, such as is disclosed with respect to the corresponding surfaces of each of the plates72. This increase in surface area accordingly allows for an increased heat exchange efficiency of the plates172. Each of the flow structures185includes a substantially rounded rectangular perimeter shape in the illustrated embodiment, but the flow structures185may include substantially any perimeter shape while remaining within the scope of the present invention. The flow structures185may also include any inclination of the surfaces forming the indented or projecting surfaces thereof, as desired.

In the illustrated embodiment, each of the projections187formed by one of the flow structures185of one of the first plates172ais configured to extend towards and contact another one of the projections187of one of the second plates172bthat is axially aligned therewith, thereby adding additional points of contact between each of the pairings of the plates172a,172balong the same plane as the contact established along the corresponding third contact portions87of each of the pairings of the plates172a,172b. The projections187of adjacent plates172a,172bmay be coupled to each other by means of an aggressive joining process such as brazing, as desired, and may be coupled to each other when the stack of the plates172a,172bis coupled together at the remaining contact portions83,87. The contact present between the adjacent projections187results in the formation of flow divisions within each of the internal flow passages75where the refrigerant passing through the internal flow passages75can divide and then recombine. The axial extension of the indentations186also results in a variable expansion and contraction of each of the external flow passages76as the liquid refrigerant passes by the indentations186. The addition of the flow structures185accordingly aids in introducing turbulence into the corresponding fluid flows and/or promoting increased mixing of each of the corresponding fluid flows, each of which aids in promoting improved heat exchange efficiency of the plates172in addition to the effects realized by the increase in surface area described above.

The flow structures185are shown inFIG.10as having a hexagonal or honey-comb like pattern relative to the planar portion81of each of the plates172, also referred to as an alternating offset pattern, for forming a slaloming or serpentine shaped flow of the refrigerant when passing through the internal flow passages75. However, the flow structures185may have alternative configurations or patterns along the planar portion81, including irregular arrangements, while remaining within the scope of the present invention. The flow structures185may also be provided at any desired density within the planar portion81for prescribing the desired degree of heat exchange.

The stack of the plates172a,172bshown inFIG.11includes the incorporation of the fin elements140therein for further improving the heat exchange capacity present within each of the external flow passages76. That is, the stack of the plates172a,172bincludes a repeating pattern of one of the first plates172a, one of the second plates172b, and one of the fin elements140, which results in each of the fin elements140being disposed axially between one of the second plates172bof a first pairing of the plates172a,172band one of the first plates172aof a second and adjacent pairing of the plates172a,172b.

In alternative embodiments, the fin elements140may be shaped for reception along portions of the internal flow passages75devoid of the flow structures185, thereby resulting in additional layers of the fin elements140. In yet other embodiments, the flow structures185may extend from the planar portion81in an opposite axial direction for establishing the flow divisions within the external flow passages76in the same fashion as that described with reference to the internal flow passages75. In some embodiments, the flow structures185may extend axially in both axial directions for establishing flow divisions within each of the flow passages75,76. In other embodiments, at least some of the flow structures185do not contact the flow structures185of an adjacent plate172, thereby establishing those flow structures185as projections extending into the corresponding flow passage75,76for diverting flow absent the complete segregation and division thereof.

From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.