CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from and the benefit of U.S. Provisional Application No. 63/404,814, entitled “OIL PURIFIER FOR AN HVAC SYSTEM,” filed September 8, 2022, which is herein incorporated by reference in its entirety for all purposes.

BACKGROUND

[0002] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0003] Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, such as vapor compression systems, utilize a working fluid (e.g., a refrigerant) that changes phases between vapor, liquid, and combinations thereof in response to exposure to different temperatures and pressures within components of the HVAC&R system. The HVAC&R system may include a working fluid circuit configured to place the working fluid in a heat exchange relationship with a conditioning fluid (e.g., water) and may deliver the conditioning fluid to conditioning equipment and/or a conditioned environment serviced by the HVAC&R system. For example, the HVAC&R system may include a heat exchanger configured to receive the working fluid and the conditioning fluid to place the working fluid in the heat exchange relationship with the conditioning fluid. The conditioning fluid may be directed from the heat exchanger to other equipment, such as air handlers, to condition other fluids, such as air in a building. The HVAC&R system may also include other components, such as a compressor configured to pressurize the working fluid and direct the working fluid through the HVAC&R system. In many applications, the HVAC&R system may include a lubrication system configured to supply a lubricant to components of the HVAC&R system, such as the compressor. Unfortunately, the working fluid and the lubricant may mix or otherwise be combined within the HVAC&R system, which may reduce the efficiency of the HVAC&R system.

SUMMARY

[0004] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0005] In one embodiment, a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes an evaporator disposed along a working fluid circuit, where the evaporator is configured to transfer heat between a working fluid and a conditioning fluid, and a lubricant separation system. The lubricant separation system includes a lubricant separation heat exchanger configured to receive a mixture of the working fluid and a lubricant from the evaporator and to transfer heat from a flow of heated fluid to the mixture to separate the working fluid from the lubricant. The lubricant separation system is also configured to direct the working fluid separated from the lubricant to the evaporator.

[0006] In another embodiment, a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes an evaporator disposed along a working fluid circuit and a lubricant separation heat exchanger configured to place a mixture of working fluid and lubricant received from the evaporator in a heat exchange relationship with a flow of heated fluid received from a heated fluid source to separate the mixture into an evaporated working fluid and a separated lubricant. The lubricant separation heat exchanger includes a first inlet configured to receive the mixture from the evaporator, a second inlet configured receive the flow of heated fluid from the heated fluid source, a first outlet configured to direct the evaporated working fluid to the evaporator, and a second outlet configured to discharge the separated lubricant from the lubricant separation heat exchanger.

[0007] In another embodiment, a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes an evaporator disposed along a working fluid circuit, a compressor system disposed along the working fluid circuit and having a centrifugal compressor configured to direct a working fluid along the working fluid circuit, a lubricant reservoir configured to supply a lubricant to the centrifugal compressor, and a lubricant separation system having a lubricant separation heat exchanger. The lubricant separation heat exchanger is configured to transfer heat from a heated flow of lubricant received from the lubricant reservoir to a mixture of working fluid and lubricant received from the evaporator to separate the mixture into an evaporated working fluid and a separated lubricant. The lubricant separation system is configured to direct the evaporated working fluid from the lubricant separation heat exchanger to the evaporator, to direct the heated flow of lubricant from the lubricant separation heat exchanger to the compressor system, and to direct the separated lubricant to the lubricant reservoir.

DRAWINGS

[0008] Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:

[0009] FIG. 1 is a perspective view of a building utilizing an embodiment of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system in a commercial setting, in accordance with an aspect of the present disclosure;

[0010] FIG. 2 is a perspective view of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure;

[0011] FIG. 3 is a schematic of an embodiment of the vapor compression system of FIG. 2, in accordance with an aspect of the present disclosure;

[0012] FIG. 4 is a schematic of an embodiment of the vapor compression system of FIG. 2, in accordance with an aspect of the present disclosure;

[0013] FIG. 5 is a schematic of an embodiment of an HVAC&R system including a working fluid circuit and a lubricant separation system, in accordance with an aspect of the present disclosure;

[0014] FIG. 6 is a schematic axial view of an embodiment of an evaporator of a working fluid circuit and a lubricant separation heat exchanger of a lubricant separation system, in accordance with an aspect of the present disclosure;

[0015] FIG. 7 is a cross-sectional schematic axial view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system, in accordance with an aspect of the present disclosure;

[0016] FIG. 8 is a cross-sectional schematic top view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system, in accordance with an aspect of the present disclosure;

[0017] FIG. 9 is a cross-sectional schematic axial view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system, in accordance with an aspect of the present disclosure;

[0018] FIG. 10 is a cross-sectional schematic top view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system, in accordance with an aspect of the present disclosure; [0019] FIG. 11 is a cross-sectional schematic side view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system, in accordance with an aspect of the present disclosure;

[0020] FIG. 12 is a schematic of an embodiment of an evaporator of a working fluid circuit and a lubricant separation heat exchanger of a lubricant separation system, illustrating fluid connections between the evaporator and the lubricant separation heat exchanger, in accordance with an aspect of the present disclosure;

[0021] FIG. 13 is a schematic axial view of an embodiment of an evaporator of a working fluid circuit and a lubricant separation heat exchanger of a lubricant separation system, illustrating fluid connections between the evaporator and the lubricant separation heat exchanger receiving a single heated source fluid, in accordance with an aspect of the present disclosure; and

[0022] FIG. 14 is a schematic axial view of an embodiment of an evaporator of a working fluid circuit and a lubricant separation heat exchanger of a lubricant separation system, illustrating fluid connections between the evaporator and the lubricant separation heat exchanger receiving two heated source fluids, in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

[0023] One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0024] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0025] As used herein, the terms “approximately,” “generally,” “substantially,” and so forth, are intended to convey that the property value being described may be within a relatively small range of the property value, as those of ordinary skill would understand. For example, when a property value is described as being “approximately” equal to (or, for example, “substantially similar” to) a given value, this is intended to convey that the property value may be within +/- 5%, within +/- 4%, within +/- 3%, within +/- 2%, within +/- 1%, or even closer, of the given value. Similarly, when a given feature is described as being “substantially parallel” to another feature, “generally perpendicular” to another feature, and so forth, this is intended to convey that the given feature is within +/- 5%, within +/- 4%, within +/- 3%, within +/- 2%, within +/- 1%, or even closer, to having the described nature, such as being parallel to another feature, being perpendicular to another feature, and so forth. Mathematical terms, such as “parallel” and “perpendicular,” should not be rigidly interpreted in a strict mathematical sense, but should instead be interpreted as one of ordinary skill in the art would interpret such terms. For example, one of ordinary skill in the art would understand that two lines that are substantially parallel to each other are parallel to a substantial degree, but may have minor deviation from exactly parallel.

[0026] Embodiments of the present disclosure relate to a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, such as a chiller or chiller system (e g., centrifugal chiller), having a vapor compression system. The vapor compression system (e.g., a vapor compression circuit) may circulate a working fluid (e.g., a heat transfer fluid, a refrigerant) through a working fluid circuit in order to cool and/or heat a conditioning fluid (e.g., water). The HVAC&R system may then direct the conditioning fluid to other equipment to condition a space and/or a component serviced by the HVAC&R system. The vapor compression system may include one or more heat exchangers configured to enable transfer of thermal energy (e.g., heat) between the working fluid and another fluid, such as the conditioning fluid. For example, the vapor compression system may include an evaporator configured to place the working fluid in a heat exchange relationship with the conditioning fluid to enable heat transfer from the conditioning fluid to the working fluid in order to cool the conditioning fluid (e.g., reduce a temperature of the conditioning fluid).

[0027] The vapor compression system may also include a compressor (e.g., compressor system, centrifugal compressor) disposed along the working fluid circuit. The compressor may operate to drive or force flow of the working fluid along the working fluid circuit. As will be appreciated, the compressor may include one or more components, such as an impeller, a shaft, and/or other components, configured to rotate during operation of the compressor. To this end, the compressor may also include one or more bearings configured to enable and/or facilitate rotation of components of the compressor, such as a shaft of the compressor. The bearings may have any suitable configuration or design and may include, for example, magnetic bearings, roller bearings, ball bearings, bearing surfaces, fluid bearings, hydrostatic bearings, hydrodynamic bearings, radial bearings, thrust bearings, active bearings, passive bearings, another type of bearing, or any combination thereof. In some embodiments, the bearings may utilize a lubricant (e.g., oil) to facilitate improved rotation of one or more components of the compressor. Unfortunately, in certain existing systems, an amount (e.g., a portion) of lubricant supplied to the compressor may become mixed with the working fluid circulated by the compressor. In some instances, lubricant mixed or entrained within the working fluid may be directed to other components of the working fluid circuit, such as one or more heat exchangers of the HVAC&R system. It is desirable to collect lubricant within the working fluid circuit and direct the lubricant back to the compressor for utilization with the bearings and/or other lubricated components of the compressor. For example, lubricant within the evaporator of the HVAC&R system may be at least partially separated from the working fluid within the evaporator as working fluid evaporates within the evaporator. Unfortunately, lubricant collected for return to the compressor may include a remaining amount of working fluid entrained within the lubricant, which may reduce effectiveness of the lubricant to lubricate components within the compressor.

[0028] Thus, it is now recognized that improved systems and methods for separating working fluid (e.g., refrigerant) and lubricant (e.g., oil) within a vapor compression system are desired. Accordingly, the present disclosure is directed to a lubricant separation system for the vapor compression system. The lubricant separation system is configured to enable improved separation of working fluid and lubricant that is mixed together within the working fluid circuit of the vapor compression system. In particular, the lubricant separation system includes a heat exchanger configured to receive a mixture of lubricant and working fluid that is collected within the working fluid circuit, such as collected within an evaporator of the working fluid circuit. The heat exchanger may also receive a heated fluid, such as heated lubricant, and may place the heated fluid in a heat exchange relationship with the mixture of lubricant and working fluid. Specifically, the heat exchanger may enable transfer of heat from the heated fluid to the mixture of lubricant and working fluid. In this way, working fluid within the mixture of lubricant and working fluid may evaporate and thereby separate from the lubricant. The evaporated working fluid may be directed back to the evaporator or other suitable portion of the working fluid circuit, while the lubricant may be directed back to the compressor for use as a lubricating fluid. By enabling improved separation of mixed working fluid and lubricant, the present techniques enable improved operation of the vapor compression system. For example, the lubricant directed back to the compressor may be more concentrated and may better function to lubricate components within the compressor. Additionally, the working fluid circulated through the working fluid circuit may include less lubricant mixed therein, which may increase efficiency of the vapor compression circuit.

[0029] Turning now to the drawings, FIG. 1 is a perspective view of an embodiment of an environment for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system 10 in a building 12 for a typical commercial setting. The HVAC&R system 10 may include a vapor compression system 14 (e.g., a chiller) that supplies a chilled liquid, which may be used to cool the building 12. The HVAC&R system 10 may also include a boiler 16 to supply warm liquid to heat the building 12 and an air distribution system which circulates air through the building 12. The air distribution system can also include an air return duct 18, an air supply duct 20, and/or an air handler 22. In some embodiments, the air handler 22 may include a heat exchanger that is connected to the boiler 16 and the vapor compression system 14 by conduits 24. The heat exchanger in the air handler 22 may receive either heated liquid from the boiler 16 or chilled liquid from the vapor compression system 14, depending on the mode of operation of the HVAC&R system 10. The HVAC&R system 10 is shown with a separate air handler on each floor of building 12, but in other embodiments, the HVAC&R system 10 may include air handlers 22 and/or other components that may be shared between or among floors.

[0030] FIGS. 2 and 3 are embodiments of the vapor compression system 14 that can be used in the HVAC&R system 10. The vapor compression system 14 may circulate a working fluid (e.g., a heat transfer fluid, a refrigerant) through a circuit starting with a compressor 32. The circuit may also include a condenser 34, an expansion valve(s) or device(s) 36, and a liquid chiller or an evaporator 38. The vapor compression system 14 may further include a control panel 40 that has an analog to digital (A/D) converter 42, a microprocessor 44, a non-volatile memory 46, and/or an interface board 48.

[0031] Some examples of fluids that may be used as working fluids in the vapor compression system 14 are hydrofluorocarbon (HFC) based refrigerants, for example, R- 410A, R-407, R-134a, R-1234ze, R1233zd, hydrofluoro olefin (HFO), “natural” refrigerants like ammonia (NH3), R-717, carbon dioxide (CO2), R-744, or hydrocarbon based refrigerants, water vapor, or any other suitable refrigerant. In some embodiments, the vapor compression system 14 may be configured to efficiently utilize working fluids having a normal boiling point of about 19 degrees Celsius (66 degrees Fahrenheit) at one atmosphere of pressure, also referred to as low pressure working fluids, versus a medium pressure working fluid, such as R-134a. As used herein, “normal boiling point” may refer to a boiling point temperature measured at one atmosphere of pressure.

[0032] In some embodiments, the vapor compression system 14 may use one or more of a variable speed drive (VSDs) 52, a motor 50, the compressor 32, the condenser 34, the expansion valve or device 36, and/or the evaporator 38. The motor 50 may drive the compressor 32 and may be powered by a variable speed drive (VSD) 52. The VSD 52 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 50. In other embodiments, the motor 50 may be powered directly from an AC or direct current (DC) power source. The motor 50 may include any type of motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.

[0033] The compressor 32 compresses a working fluid vapor and delivers the vapor to the condenser 34 through a discharge passage. In some embodiments, the compressor 32 may be a centrifugal compressor. The working fluid vapor delivered by the compressor 32 to the condenser 34 may transfer heat to a cooling fluid (e.g., water or air) in the condenser 34. The working fluid vapor may condense to a working fluid liquid in the condenser 34 due to thermal heat transfer with the cooling fluid. The liquid working fluid from the condenser 34 may flow through the expansion device 36 to the evaporator 38. In the illustrated embodiment of FIG. 3, the condenser 34 is water cooled and includes a tube bundle 54 connected to a cooling tower 56, which supplies the cooling fluid to the condenser 34.

[0034] The liquid working fluid delivered to the evaporator 38 may absorb heat from a conditioning fluid, which may or may not be the same cooling fluid used in the condenser 34. The liquid working fluid in the evaporator 38 may undergo a phase change from the liquid working fluid to a working fluid vapor. As shown in the illustrated embodiment of FIG. 3, the evaporator 38 may include a tube bundle 58 having a supply line 60S and a return line 60R connected to a cooling load 62. The conditioning fluid of the evaporator 38 (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) enters the evaporator 38 via return line 60R and exits the evaporator 38 via supply line 60S. The evaporator 38 may reduce the temperature of the conditioning fluid in the tube bundle 58 via thermal heat transfer with the working fluid. The tube bundle 58 in the evaporator 38 can include a plurality of tubes and/or a plurality of tube bundles. In any case, the vapor working fluid exits the evaporator 38 and returns to the compressor 32 by a suction line to complete the cycle.

[0035] FIG. 4 is a schematic of the vapor compression system 14 with an intermediate circuit 64 incorporated between condenser 34 and the expansion device 36. The intermediate circuit 64 may have an inlet line 68 that is directly fluidly connected to the condenser 34. In other embodiments, the inlet line 68 may be indirectly fluidly coupled to the condenser 34. As shown in the illustrated embodiment of FIG. 4, the inlet line 68 includes a first expansion device 66 positioned upstream of an intermediate vessel 70. In some embodiments, the intermediate vessel 70 may be a flash tank (e.g., a flash intercooler, an economizer, etc.). In other embodiments, the intermediate vessel 70 may be configured as a heat exchanger or a “surface economizer.” In the illustrated embodiment of FIG. 4, the intermediate vessel 70 is used as a flash tank, and the first expansion device 66 is configured to lower the pressure of (e.g., expand) the liquid working fluid received from the condenser 34. During the expansion process, a portion of the liquid may vaporize, and thus, the intermediate vessel 70 may be used to separate the vapor from the liquid received from the first expansion device 66.

[0036] Additionally, the intermediate vessel 70 may provide for further expansion of the liquid working fluid because of a pressure drop experienced by the liquid working fluid when entering the intermediate vessel 70 (e.g., due to a rapid increase in volume experienced when entering the intermediate vessel 70). The vapor in the intermediate vessel 70 may be drawn by the compressor 32 through a suction line 74 of the compressor 32 In other embodiments, the vapor in the intermediate vessel may be drawn to an intermediate stage of the compressor 32 (e.g., not the suction stage). The liquid that collects in the intermediate vessel 70 may be at a lower enthalpy than the liquid working fluid exiting the condenser 34 due to expansion in the expansion device 66 and/or the intermediate vessel 70. The liquid from intermediate vessel 70 may then flow in line 72 through a second expansion device 36 to the evaporator 38.

[0037] It should be appreciated that any of the features described herein may be incorporated with the vapor compression system 14 or any other suitable HVAC&R systems. For example, the present techniques may be incorporated with any HVAC&R system having an economizer, such as the intermediate vessel 70, and a compressor, such as the compressor 32. The discussion below describes the present techniques incorporated with embodiments of the compressor 32 configured as a single stage compressor. However, it should be noted that the systems and methods described herein may be incorporated with other embodiments of the compressor 32 and HVAC&R system 10.

[0038] With the foregoing in mind, FIG. 5 is a schematic of an embodiment of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system 100, such as a centrifugal chiller system The HVAC&R system 100 includes similar elements as those described above. For example, the HVAC&R system 100 includes a working fluid circuit 102 (e.g., vapor compression circuit) having a compressor system 104, a condenser 106, and expansion valve 108, and an evaporator 110. The working fluid circuit 102 may circulate a working fluid therethrough to enable heat transfer between the working fluid and one or more additional fluids, such as a conditioning fluid, a cooling fluid, another suitable fluid, or any combination thereof.

[0039] The HVAC&R system 100 also includes a lubricant separation system 112 configured to enable improved separation of mixed working fluid and lubricant within the working fluid circuit 102. As mentioned above, the compressor system 104 may include one or more compressors 114 and one or more components configured to rotate during operation of the compressor system 104. The HVAC system 100 may therefore be configured to supply a lubricant (e.g., oil) to the compressor system 104 (e.g., to bearings of the compressor system 104) to facilitate rotation of such rotating components. To this end, the HVAC&R system 100 may include a lubricant reservoir 116 configured to store lubricant and supply the lubricant to the compressor system 104. However, during operation of the HVAC&R system 100, an amount of lubricant supplied to the compressor system 104 may become mixed with the working fluid circulated through the working fluid circuit 102 by the compressor system 104. In some instances, the lubricant mixed with the working fluid may be directed along the working fluid circuit 102 towards other components of the working fluid circuit 102, such as the evaporator 110. Indeed, in some applications, lubricant mixed with working fluid may collected within certain components of the working fluid circuit 102. Accordingly, present embodiments include the lubricant separation system 112 configured to enable improved separation of lubricant and working fluid that has mixed together within the HVAC&R system 100. In the manner described below, the working fluid and lubricant may be separated from one another and may be separately directed to suitable portions or components of the HVAC&R system 100.

[0040] In the illustrated embodiment, the lubricant separation system 112 includes a lubricant separation heat exchanger 1 18 configured to enable separation of lubricant from working fluid that has mixed together within the working fluid circuit 102 (e.g., within the compressor system 104). Configurations and embodiments of the lubricant separation heat exchanger 118 are described in further detail below. In operation, the lubricant separation heat exchanger 118 is configured to receive a flow of lubricant and working fluid from a component of the working fluid circuit 102. For example, in the illustrated embodiment, the lubricant separation heat exchanger 118 is configured to receive a mixture of lubricant and working fluid from the evaporator 110 of the working fluid circuit 102, as indicated by arrow 120. The mixture may include lubricant and a portion of liquid working fluid collected within the evaporator 110.

[0041] The lubricant separation heat exchanger 118 is also configured to receive a flow of heated fluid and to place the flow of heated fluid in a heat exchange relationship with the mixture of lubricant and working fluid. The flow of heated fluid may be any suitable heated fluid supplied by any suitable source. For example, the flow of heated fluid may be a flow of heated lubricant supplied by the lubricant reservoir 116, as indicated by arrow 122. In some embodiments, the flow of heated lubricant may be directed to the lubricant separation heat exchanger 118 by a pump 124 of the lubricant reservoir 116. Additionally or alternatively, the lubricant reservoir 116 may include a heater 126 (e.g., heating element) configured to heat the lubricant for supply to the lubricant separation heat exchanger 118, such as during initial startup of the HVAC&R system 100. The lubricant separation heat exchanger 118 may configured to place the heated lubricant in a heat exchange relationship (e.g., a fluidly separate heat exchange relationship) with the mixture of lubricant and working fluid to enable transfer of heat from the heated lubricant to the mixture of lubricant and working fluid. As a result, liquid working fluid mixed with the lubricant may evaporate and become separated from the lubricant. Thereafter, the evaporated working fluid may be directed from the lubricant separation heat exchanger 118 back to the evaporator 110, as indicated by arrow 128, by the lubricant separation system 112.

[0042] The lubricant remaining within the lubricant separation heat exchanger 1 18 from the initial mixture of lubricant and working fluid may be directed to return to the lubricant reservoir 116. In some embodiments, the separated and/or concentrated lubricant within the lubricant separation heat exchanger 118 may be directed toward an eductor 130 (e.g., jet pump, ejector, vacuum pump), as indicated by arrow 132 (e.g., a conduit), by the lubricant separation system 112. The eductor 130 may receive the separated and/or concentrated lubricant from the lubricant separation heat exchanger 118 as an inlet or suction fluid. The eductor 130 may also receive a flow of a motive fluid to enable generation of a differential pressure or vacuum within the eductor 130 and thereby cause the eductor 130 to draw the separated and/or concentrated lubricant into the eductor 130 from the lubricant separation heat exchanger 118. In some embodiments, the motive fluid supplied to the eductor 130 may be a high-pressure working fluid gas or vapor (e.g., pressurized fluid) directed to the eductor 130 from the compressor system 104, as indicated by arrow 134. In some embodiments, the pressurized working fluid gas may be discharged from a discharge port of one of the compressors 114 of the compressor system 104. For example, the compressors 114 may include a first compressor 136 (e.g., first stage compressor, low stage compressor) and a second compressor 138 (e.g., second stage compressor, high stage compressor) arranged in series (e.g., relative to flow of working fluid through the compressor system 104), and the pressurized working fluid gas may be directed from a discharge of the first compressor 136 to the eductor 130. However, in other embodiments, the motive fluid supplied to the eductor 130 may be provided by another portion of the compressor system 104 (e.g., an intermediate stage of a multi-stage compressor) or another suitable source of pressurized fluid.

[0043] In the illustrated embodiment, the eductor 130 is configured to direct a mixture of the concentrated lubricant and the high-pressure working fluid gas to the lubricant reservoir 116. As will be appreciated, the concentrated lubricant and the high- pressure working fluid gas may not readily mix within the eductor 130 and/or the lubricant reservoir 116. Accordingly, the high-pressure working fluid gas may be directed back to the compressor system 104 (e.g., to the second compressor 138) to mix with working fluid directed along the working fluid circuit 102, as indicated by arrow 140. The working fluid by the lubricant reservoir 116 from the eductor 130 may evaporate into working fluid vapor by absorbing heat from the heated lubricant within the lubricant reservoir 116 and may be directed to the compressor system 104, as indicated by arrow 142. As will be appreciated, the lubricant reservoir 116 is also configured to receive lubricant from the compressor system 104, as indicated by arrow for reconditioning (e.g., cooling) and subsequent use to lubricate components of the compressor system 104, as indicated by arrow 144. While the present discussion describes return of the concentrated lubricant from the lubricant separation heat exchanger 118 to the lubricant reservoir 116 via operation of the eductor 130, it should be appreciated that the lubricant separation system 112 may include additional or alternative components to enable flow of the separated lubricant from the lubricant separation heat exchanger 118 to the lubricant reservoir 116. For example, the lubricant separation system 112 may include one or more conduits, valves, pumps, other suitable components, or any combination thereof to enable flow of separated and/or concentrated lubricant from the lubricant separation heat exchanger 118 to the lubricant reservoir 116.

[0044] Turning back to discussion of the operation of the lubricant separation heat exchanger 118, the heated lubricant directed through the lubricant separation heat exchanger 118 as the heated fluid may decrease in temperature as the heated lubricant transfers heat to the mixture of lubricant and working fluid within the lubricant separation heat exchanger 118. Thus, in some embodiments, the lubricant separation heat exchanger 118 may additional function as a cooling system for the lubricant within the lubricant reservoir 116. As a result, certain embodiments of the HVAC&R system 100 may not include a separate and/or dedicated cooling system to cool lubricant within the lubricant reservoir 116 that is received from the compressor system 104. Additionally or alternatively, the HVAC&R system 100 may include a lubricant cooling system that operates with reduced power consumption. The lubricant directed through the lubricant separation heat exchanger 118 as the heated fluid may be discharged by the lubricant separation heat exchanger 118 and be directed from the lubricant separation heat exchanger 1 18 to the compressor system 104 (e g., by the lubricant separation system 112) for use with lubricating components, such as bearings, of the compressor system 104, as indicated by arrow 146 (e.g., a conduit). That is, the lubricant utilized as the heated fluid within the lubricant separation heat exchanger 118 may not be directed back to the lubricant reservoir 116, in some embodiments.

[0045] In further embodiments, the lubricant separation system 112 may utilize additional or alternative fluids as the heated fluid to enable transfer of heat to the mixture of lubricant and working fluid within the lubricant separation heat exchanger 118. For example, the HVAC&R system 100 may include a control system 148 (e.g., controller, automation controller, control board) that includes and/or utilizes a cooling system 150 configured to cool one or more electronic components of the control system 148

[0046] In some embodiments, the control system 148 may include processing circuitry 152, such as a microprocessor, which may execute software for controlling the components of the HVAC&R system 100. The processing circuitry 152 may include multiple microprocessors, one or more “general-purpose” microprocessors, one or more special-purpose microprocessors, and/or one or more application specific integrated circuits (ASICS), or some combination thereof. For example, the processing circuitry 152 may include one or more reduced instruction set (RISC) processors. The control system 148 may also include a memory device 154 (e.g., a memory) that may store information, such as instructions, control software, look up tables, configuration data, etc. The memory device 154 may include a volatile memory, such as random access memory (RAM), and/or a nonvolatile memory, such as read-only memory (ROM). The memory device 154 may store a variety of information and may be used for various purposes. For example, the memory device 154 may store processor-executable instructions including firmware or software for the processing circuitry 152 execute, such as instructions for controlling components of the HVAC&R system 100. In some embodiments, the memory device 154 is a tangible, non-transitory, machine-readable-medium that may store machine-readable instructions for the processing circuitry 152 to execute. The memory device 154 may include ROM, flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The memory device 154 may store data, instructions, and any other suitable data. Further, the control system 148 may include a variable speed drive (VSD) 156, which may be configured to operate one or more of the compressors 114 at variable speeds, as similarly discussed above.

[0047] In some embodiments, the cooling system 150 may circulate a cooling fluid (e.g., water, glycol, mixture of water and glycol) and place the cooling fluid in a heat exchange relationship with one or more components of the control system 148, such as the VSD 156. In this way, the cooling fluid circulated by the cooling system 150 may absorb heat from components (e.g., electrical components) of the control system 148. As the cooling fluid absorbs heat from components (e.g., electrical components) of the control system 148, the cooling fluid may become heated. The cooling fluid may therefore be suitable for use as the heated fluid directed through the lubricant separation heat exchanger 118. Thus, the control system 148 (e.g., cooling system 150, heated fluid source) may be configured to direct the cooling fluid to the lubricant separation heat exchanger 118, as indicated by arrow 158, after the cooling fluid absorbs heat from components of the control system 148. Within the lubricant separation heat exchanger 118, the cooling fluid may transfer heat to the mixture of lubricant and working fluid, thereby reducing a temperature of the cooling fluid to recondition (e.g., cool) the cooling fluid for subsequent use within the cooling system 150 to cool components of the control system 148. The cooling fluid may therefore be directed from the lubricant separation heat exchanger 118 back to the cooling system 150, as indicated by arrow 160.

[0048] Additionally or alternatively, the lubricant separation system 112 may utilize a flow of the working fluid as the heated fluid to enable transfer of heat to the mixture of lubricant and working fluid within the lubricant separation heat exchanger 118. For example, as indicated by arrow 162, a flow of working fluid (e.g., heated working fluid, condensed working fluid) may be directed from the condenser 106 (e.g., heated fluid source) to the lubricant separation heat exchanger 118. Within the lubricant separation heat exchanger 118, heat may be transferred from the flow of working fluid to the mixture of lubricant and working fluid (e.g., to vaporize the working fluid within the mixture). In this way, the lubricant separation heat exchanger 118 may operate to subcool and/or further subcool the flow of working fluid utilized as the heated fluid. Thereafter, the flow of working fluid utilized as the heated fluid may be directed back to the working fluid circuit 102, such as downstream of the condenser 106 and upstream of the expansion valve 108, as indicated by arrow 164.

[0049] FIG. 6 is a schematic axial view of an embodiment of the evaporator 110 of the working fluid circuit 102 and the lubricant separation heat exchanger 118 of the lubricant separation system 112, in accordance with an aspect of the present disclosure As discussed above, the lubricant separation heat exchanger 118 is configured to receive a mixture of lubricant and working fluid 180 from the evaporator 110 and to receive a flow of heated fluid 182, such as a flow of heated lubricant, to enable transfer of heat from the flow of heated fluid to the mixture of lubricant and working fluid. As heat is transferred to the mixture of lubricant and working fluid, liquid working fluid within the mixture may evaporate and become separated from lubricant within the mixture, which may remain in the liquid phase. In this way, the lubricant may become concentrated and/or separated lubricant 184 that may be discharged from the lubricant separation heat exchanger 118 and directed toward the lubricant reservoir 116 (e.g., the eductor 130) for use in lubricating components of the compressor system 104. Evaporated (e.g., vaporized, separated) working fluid 186 that is separated from the lubricant may be directed from the lubricant separation heat exchanger 118 back to the evaporator 110.

[0050] In some embodiments, the evaporator 110 may be a hybrid falling film evaporator. That is, the evaporator 110 may include a shell 188 (e.g., a housing) with a falling film section 190 and a flooded section 192 disposed therein. The falling film section 190 may be disposed vertically above the flooded section 192 with respect to a direction of gravity. The falling film section 190 and the flooded section 192 may each include a respective plurality of tubes extending therethrough and configured to circulate a conditioning fluid. As will be appreciated, liquid working fluid within the shell 188 of the evaporator 110 may collect within the flooded section 192 of the evaporator 110. Lubricant within the shell 188 of the evaporator 110, such as lubricant that initially enters the flow of working fluid within the compressor system 104, may also collect within the flooded section 192. As a result, a mixture of liquid working fluid and lubricant may collect and/or accumulate within the flooded section 192 of the evaporator 110. Accordingly, the lubricant separation system 112 may include a first conduit 194 (e.g., inlet conduit, first inlet conduit) extending from the flooded section 192 (e.g., the shell 188) to the lubricant separation heat exchanger 118, where the first conduit 194 is configured to direct the mixture of lubricant and working fluid 180 from the evaporator 1 10 to the lubricant separation heat exchanger 1 18, such as via force of gravity. The lubricant separation system 112 may also include a first outlet conduit 196 configured to discharge the concentrated and/or separated lubricant 184 from the lubricant separation heat exchanger 118 and direct the separated lubricant 184 toward the lubricant reservoir 116 and/or the eductor 130. Further, the lubricant separation system 112 may include a second outlet conduit 198 configured to direct the evaporated and/or separated working fluid 186 from the lubricant separation heat exchanger 118 back to the evaporator 110. For example, the second outlet conduit 198 may extend from a top portion of the lubricant separation heat exchanger 118 to the shell 188 at and/or adjacent the falling film section 190 of the evaporator 110.

[0051] To enable heat exchange between the mixture of lubricant and working fluid 180 and the flow of heated fluid 182, the lubricant separation heat exchanger 118 may include a heat transfer apparatus 200 (e.g., heat transfer device, heat transfer block, heat transfer assembly) configured to place the mixture of lubricant and working fluid 180 and the flow of heated fluid 182 in a heat exchange relationship with one another. As discussed in further detail below, the heat transfer apparatus 200 may also be positioned within a shell 202 of the lubricant separation heat exchanger 118 in a manner that maintains fluid separation of the mixture of lubricant and working fluid 180 from the flow of heated fluid 182 within the lubricant separation heat exchanger 118. As also described further below, the mixture of lubricant and working fluid 180 directed into the shell 202 by the first conduit 194 may flow through and/or across the heat transfer apparatus 200 toward the first outlet conduit 196.

[0052] In some embodiments, the lubricant separation heat exchanger 118 may include a first header 204 (e.g., first manifold) configured to direct the flow of heated fluid 182 into the heat transfer apparatus 200 and a second header 206 (e.g., second manifold) configured to receive the flow of heated fluid 182 from the heat transfer apparatus 200 and to discharge the flow of heated fluid 182 from the lubricant separation heat exchanger 118. In some embodiments, the first conduit 194, the first outlet conduit 196, the heat transfer apparatus 200, the first header 204, and/or the second header 206 may be arranged such that the mixture of lubricant and working fluid 180 and the flow of heated fluid 182 are directed through the heat transfer apparatus 200 in a counterflow arrangement. In this way, heat transfer between the mixture of lubricant and working fluid 180 and the flow of heated fluid 182 may be improved, thereby increasing separation of working fluid from lubricant within the lubricant separation heat exchanger 118.

[0053] FIG. 7 is a cross-sectional schematic axial view of an embodiment of the lubricant separation heat exchanger 118 of the lubricant separation system 112, in accordance with an aspect of the present disclosure. As mentioned above, the lubricant separation heat exchanger 118 includes the heat transfer apparatus 200 disposed within the shell 202 of the lubricant separation heat exchanger 118. In the illustrated embodiment, the heat transfer apparatus 200 includes a block structure 220 defining a plurality of channels 222 extending through the block structure 220. The plurality of channels 222 may extend serially or sequentially from a first side 224 of the block structure 220 to a second side 226 of the block structure 220. The plurality of channels 222 may therefore define a flow path from the first side 224 to the second side 226 of the block structure 220 To define the plurality of channels 222, the block structure 220 includes a plurality of extensions 228 (e.g., protrusions, vertical extensions, projections, legs, etc.) extending (e.g., vertically extending) from a base portion 230 of the block structure 220. In some embodiments, the plurality of channels 222 may extend between corresponding, adjacent extensions 228 to define a serpentine flow path from the first side 224 to the second side 226 of the block structure 220, as shown in FIG. 8.

[0054] The block structure 220 may be positioned within the shell 202 of the lubricant separation heat exchanger 118 to separate a first cavity 232 (e.g., inlet portion, intake cavity) within the shell 202 from a second cavity 234 (e.g., outlet portion, discharge cavity) within the shell 202. During operation of the lubricant separation heat exchanger 118, the mixture of lubricant and working fluid 180 may be directed into the shell 202 via an inlet 236 of the lubricant separation heat exchanger 118 that may be fluidly coupled to the first conduit 194. In particular, the mixture of lubricant and working fluid 180 may be directed from the inlet 236 into the first cavity 232. From the first cavity 232, the mixture of lubricant and working fluid 180 may flow through the plurality of channels 222 from the first side 224 of the block structure 220 to the second side 226 of the block structure 220. Indeed, lubricant separation heat exchanger 118 may be configured to block flow of the mixture of lubricant and working fluid 180 directly from the first cavity 232 to the second cavity 234 without flowing through the plurality of channels 222. For example, the lubricant separation heat exchanger 118 may include one or more seals (e.g., sealing elements, cushions, barrier elements, sealing members) configured to block the mixture of lubricant and working fluid 180 from flowing around the block structure 220, such as between the block structure 220 and the shell 202. In the illustrated embodiment, the lubricant separation heat exchanger 118 includes a base seal 238 positioned between the shell 202 and the base portion 230 of the block structure 220 to block flow of the mixture of lubricant and working fluid 180 therebetween. The lubricant separation heat exchanger 118 may include additional or alternative seals, as described below with reference to FIG. 8.

[0055] The heat transfer apparatus 200 further includes a plurality of tubes 240 positioned within and extending through the plurality of channels 222. For example, the plurality of tubes 240 may also extend through the plurality of channels 222 in a serpentine pattern. In the illustrated embodiment, the plurality of tubes 240 is vertically arrayed within the plurality of channels 222. Each tube 240 is configured to direct the heated fluid therethrough. For example, each tube 240 may include a respective inlet 242 fluidly coupled to the first header 204 and a respective outlet 244 fluidly coupled to the second header 206.

[0056] During operation of the lubricant separation heat exchanger 118, the mixture of lubricant and working fluid 180 may flow from the first cavity 232 within the shell 202, through the plurality of channels 222, and to the second cavity 234 within the shell 202, while the flow of heated fluid 182 may flow through the plurality of tubes 240 extending within the plurality of channels 222. As the mixture of lubricant and working fluid 180 and the flow of heated fluid 182 are directed through the heat transfer apparatus 200 in this manner, heat may be transferred from the flow of heated fluid 182 to the mixture of lubricant and working fluid 180, thereby causing liquid working fluid within the mixture 180 to evaporate. As indicated by arrows 246, evaporated working fluid 186 may separate from the lubricant within the mixture 180 and rise (e.g., flow upwardly) within the plurality of channels 222 toward an outlet 248 of the lubricant separation heat exchanger 118 (e.g., shell 202). As a result, the mixture of lubricant and working fluid 180 may be separated into the evaporated working fluid 186 and separated lubricant 184, and the separated lubricant 184 may collect and/or accumulate within the second cavity 234 of the shell 202. The separated lubricant 184 may flow from the second cavity 234 through an outlet 250 of the shell 202, which may be fluidly coupled to the first outlet conduit 196, to be discharged from the lubricant separation heat exchanger 118.

[0057] The components of the lubricant separation heat exchanger 118 (e.g., the heat transfer apparatus 200) may be formed from any suitable material and utilizing any suitable processes. For example, the block structure 220 may be formed from a polymer (e g., plastic) and/or a metallic material (e.g., aluminum) and may be formed via injection molding, machining, cutting, additive manufacturing (e.g., three-dimensional printing), and/or another suitable process. Similarly, seals (e.g., base seal 238) disposed between the block structure 220 and the shell 202 may be formed from any suitable material, such as plastic, metal, a compressible material, foam, a polymer, and/or another suitable material. Indeed, the components of the lubricant separation heat exchanger 118 described herein may be formed from any suitable material compatible with the working fluid and the lubricant utilized by the HVAC&R system 100.

[0058] FIG. 8 a cross-sectional schematic top view of an embodiment of the lubricant separation heat exchanger 118 of the lubricant separation system 112, in accordance with an aspect of the present disclosure. The illustrated embodiment includes similar elements and element numbers as the embodiment described above with reference to FIG. 7. For example, the lubricant separation heat exchanger 118 includes the heat transfer apparatus 200 having the block structure 220 and the plurality of tubes 240 disposed within the shell 202 of the lubricant separation heat exchanger 118. The plurality of channels 222 defined by the plurality of extensions 228 of the block structure 220 cooperatively form a serpentine flow path 260 through the block structure 220 (e.g., from the first cavity 232 to the second cavity 234 within the shell 202). Additionally, the plurality of tubes 240 extend through the shell 202 and along the serpentine flow path 260. Thus, the flow of heated fluid 182 may be directed through the plurality of tubes 240 to transfer heat to the mixture of lubricant and working fluid 180 within the serpentine flow path 260 to enable separation of the mixture 180 into evaporated working fluid 186 and concentrated lubricant 184.

[0059] The illustrated embodiment also includes additional seals 262 positioned within the shell 202 to separate the first cavity 232 from the second cavity 234. That is, similar to the base seal 238, the additional seals 262 are configured to block flow of the mixture of lubricant and working fluid 180 from the first cavity 232 directly to the second cavity 234 without flowing along the serpentine flow path 260. The additional seals 262 may be incorporated in the lubricant separation heat exchanger 1 18 in conjunction with the base seal 238 discussed above. The additional seals 262 include a first end seal 264 and a second end seal 266 positioned at respective longitudinal ends 268 of the shell 202 (e g., the block structure 220), relative to a longitudinal axis 270 of the lubricant separation heat exchanger 118. For example, the first end seal 264 may be disposed between the block structure 220 and a first end plate 272 of the shell 202, and the second end seal 266 may be disposed between the block structure 220 and a second end plate 274 of the shell 202. During assembly and/or manufacturing of the lubricant separation heat exchanger 118, the additional seals 262 may be captured between the block structure 220 and the respective end plates 272, 274, and the end plates 272, 274 may be secured (e.g., welded, bolted, fastened) to a main body 276 of the shell 202. In this way, the additional seals 262 may be secured (e g., captured, wedged) between the block structure 220 and the shell 202 to create a sealing engagement (e g., a fluid seal, a fluidic barrier) that may block direct flow of the mixture of lubricant and working fluid 180 from the first cavity 232 to the second cavity 234 without flowing through the serpentine flow path 260 defined by the plurality of channels 222.

[0060] FIG. 9 is a cross-sectional schematic axial view of an embodiment of the lubricant separation heat exchanger 118 of the lubricant separation system 112, in accordance with an aspect of the present disclosure. As similarly described above, the lubricant separation heat exchanger 118 includes the shell 202, the inlet 236 configured to receive the mixture of lubricant and working fluid 180 from the evaporator 110, the outlet 250 configured to discharge the concentrated lubricant 184, and the outlet 248 configured to discharge the evaporated working fluid 186.

[0061] The illustrated embodiment also includes an alternative embodiment of the heat transfer apparatus 200, referred to herein as a heat transfer apparatus 280. In particular, the heat transfer apparatus 280 includes an alternative embodiment of the block structure 220 including the base portion 230 and the plurality of extensions 228 extending (e.g., vertically extending) from the base portion 230 to define the plurality of channels 222 discussed above. The plurality of extensions 228 includes a plurality of ports 282 (e.g., passages, flow paths, cavities) formed therein. The plurality of ports 282 is configured to circulate the flow of heated fluid 182 therethrough, such that the flow of heated fluid 182 may flow internally through the block structure 220 (e.g., internally through the plurality of extensions 228). Accordingly, the heat transfer apparatus 280 does not include the plurality of tubes 240 discussed above.

[0062] The plurality of ports 282 extending internally through the plurality of extensions 228 may define one or more flow paths (e.g., serpentine flow paths). For example, each port 282 may be serially connected with one another, such that the plurality of ports 282 define a single flow path for the flow of heated fluid 182 through the heat transfer apparatus 280. Alternatively, the plurality of ports 282 may define multiple flow paths (e.g., multiple serpentine flow paths) configured to direct portions of the flow of heated fluid 182 through the heat transfer apparatus 280. For example, the plurality of ports 282 may define multiple flow paths arrayed vertically along the plurality of extensions 228. In such embodiments, each flow path may be fluidly coupled to the first header 204 configured to supply the flow of heated fluid 182 to the lubricant separation heat exchanger 118, and each flow path may be fluidly coupled to the second header 206 configured to discharge the flow of heated fluid 182 from the lubricant separation heat exchanger 118.

[0063] The block structure 220 of the heat transfer apparatus 280 may be similar positioned within the shell 202 of the lubricant separation heat exchanger 118 to separate the first cavity 232 from the second cavity 234 within the shell 202. In some embodiments, the heat transfer apparatus 280 may include seals (e.g., base seal 238, additional seals 262) similar to those discussed above to separate the first cavity 232 from the second cavity 234 and block the mixture of lubricant and working fluid 180 from flowing directly from the first cavity 232 to the second cavity 234 (e.g., bypassing flow through the plurality of channels 222). Additionally or alternatively, the base portion 230 of the block structure 220 may include a geometry (e.g., curvature) corresponding to (e g., matching) a geometry of the shell 202, as shown, to enable a fluidic seal between the block structure 220 and the shell 202. [0064] In the illustrated embodiment, the block structure 220 also includes a plurality of passages 284 formed within the plurality of extensions 228. In particular, each extension 228 may include one of the passages 284 formed therein, such as at a base of the respective extension 228 (e.g., adjacent the base portion 230 of the block structure 220). The passages 284 are configured to enable flow of the mixture of lubricant and working fluid 180 between adjacent channels 222 defined by the plurality of extensions 228. Thus, the passages 284 are configured to direct flow of the mixture of lubricant and working fluid 180 through the heat transfer apparatus 280 (e.g., from the first cavity 232 to the second cavity 234) via the plurality of channels 222. Tn some embodiments, the respective passages 284 of adjacent extensions 228 may be formed at opposite ends (e.g., opposite longitudinal ends, relative to longitudinal axis 270) of the block structure 220 and/or the shell 202). In this way, the plurality of channels 222 and the plurality of passages 284 may cooperatively define a serpentine flow path configured to direct the mixture of lubricant and working fluid 180 through the heat transfer apparatus 280. As the mixture of lubricant and working fluid 180 through the plurality of channels 222 and the plurality of passages 284, the mixture 180 may absorb heat from the flow of heated fluid 182 directed through the plurality of ports 282 to cause liquid working fluid within the mixture 180 to evaporate and generate the evaporated working fluid 186 and the separated lubricant 184 as similarly described above.

[0065] FIG. 10 is a cross-sectional schematic top view of another embodiment of the lubricant separation heat exchanger 118 of the lubricant separation system 112, in accordance with an aspect of the present disclosure. As similarly discussed above, the lubricant separation heat exchanger 118 is configured to receive the mixture of lubricant and working fluid 180 from the evaporator 110 and the flow of heated fluid 182 (e.g., from the lubricant reservoir 116) and place the mixture 180 in a heat transfer relationship with the flow of heated fluid 182 to enable separation of the mixture 180 into the evaporated working fluid 186 and the concentrated lubricant 184. [0066] In the illustrated embodiment, the lubricant separation heat exchanger 118 has a shell and tube configuration. That is, the lubricant separation heat exchanger 118 includes a shell 300 and a plurality of tubes 302 extending through the shell 300. The lubricant separation heat exchanger 118 further includes an inlet 304 configured to receive the mixture of lubricant and working fluid 180 from the evaporator 110 and direct the mixture 180 into the shell 300 (e.g., an internal volume of the shell 300). The lubricant separation heat exchanger 118 also includes an outlet 306 configured to discharge the separated lubricant 184 from the shell 300. As discussed in further detail below, the lubricant separation heat exchanger 1 18 may also include a plurality of baffles 308 disposed within the shell 300. The baffles 308 may define a desired flow path, such as a serpentine flow path 310, along which the mixture of lubricant and working fluid 180 may flow within the shell 300. In some embodiments, the plurality of tubes 302 may extend through one or more of the baffles 308, and the baffles 308 may be configured to also function as tube sheets that support the tubes 302 within the shell 300. The arrangement and configuration of the baffles 308 are described in further detail below.

[0067] The plurality of tubes 302 is configured to direct the flow of heated fluid 182 therethrough and to place the flow of heated fluid 182 in a heat exchange relationship with the mixture of lubricant and working fluid 180 may flow within the shell 300. In the illustrated embodiment, the plurality of tubes 302 is arranged to define a two-pass configuration of the lubricant separation heat exchanger 118. That is, the flow of heated fluid 182 may flow along a length 311 of the shell 300 twice (e.g., in opposite directions). To this end, the plurality of tubes 302 may be separated into a first subset of tubes 312 and a second subset of tubes 316, whereby the first subset of tubes 312 defines a first pass 314 of the lubricant separation heat exchanger 118, and the second subset of tubes 316 defines a second pass 318 of the lubricant separation heat exchanger 118.

[0068] The lubricant separation heat exchanger 118 includes additional features to enable sequential flow of the heated fluid 182 along the first pass 314 and the second pass 318. For example, the lubricant separation heat exchanger 118 includes a first manifold 320 (e.g., first fluid box) coupled to a first end 322 (e.g., first longitudinal end) of the shell 300. The first manifold 320 includes an inlet 324 and an outlet 326 and defines a first cavity 328 and a second cavity 330. The first cavity 328 and the second cavity 330 are separated from one another (e.g., fluidly separated) via a partition 332 of the first manifold 320. In operation, the inlet 324 may receive the flow of heated fluid 182 (e.g., from a heated fluid source, such as the lubricant reservoir 116) and direct the flow of heated fluid 182 into the first cavity 328. The first cavity 328 is fluidly coupled to the first subset of tubes 312. Thus, the flow of heated fluid 182 may be directed from the first cavity 328 and into the first subset of tubes 312 to flow along the first pass 314 of the lubricant separation heat exchanger 118.

[0069] The lubricant separation heat exchanger 118 further includes a second manifold 334 (e.g., second fluid box) coupled to a second end 336 (e.g., second longitudinal end) of the shell 300. The second manifold 334 defines an additional cavity 338 that is configured to receive the flow of heated fluid 182 from the first subset of tubes 312 and direct the flow of heated fluid 182 into the second subset of tubes 316. Thus, the second manifold 334 is configured to direct the flow of heated fluid 182 from the first pass 314 to the second pass 318 of the lubricant separation heat exchanger 118. The flow of heated fluid 182 may flow through the second subset of tubes 316 and into the second cavity 330 defined by the first manifold 320. From the second cavity 330, the flow of heated fluid 182 may be discharged from the lubricant separation heat exchanger 118 via the outlet 326. As shown, the lubricant separation heat exchanger 118 is configured to direct the mixture of lubricant and working fluid 180 into the shell 300 and initially across the second pass 318 and to exit the shell 300 after flowing across the first pass 314. Thus, the lubricant separation heat exchanger 118 may be configured in a counterflow arrangement, as similarly described above.

[0070] As mentioned above, the lubricant separation heat exchanger 1 18 may include the baffles 308 disposed within the shell 300, and the baffles 308 may be configured to define a flow path of the mixture of lubricant and working fluid 180 through the shell 300. For example, the baffles 308 may cooperatively define the serpentine flow path 310. To this end, in some embodiments, each baffle 308 may extend from the shell 300, completely across one of the passes 314, 318 and partially across the other of the passes 314, 318 (e.g., along a radial axis 340 of the lubricant separation heat exchanger 118). Thus, the baffles 308 may direct the mixture of lubricant and working fluid 180 along the serpentine flow path 310 and completely across the first pass 314 and the second pass 318 in a repeated sequence along the serpentine flow path 310.

[0071] Further, in some embodiments, the baffles 308 may be arranged in the shell 300 with variable spacings (e g., longitudinal spacings, spacing along the length 311) relative to one another. That is, each baffle 308 may be spaced apart from one or more adjacent baffles 308 by a respective distance 342 (e.g., longitudinal distance, offset, along the length 311) extending along the length 311 (e.g., longitudinal axis) between the adjacent baffles 308. For example, the distance 342 between adjacent baffles 308 may be determined based on a location of the baffles 308 within the shell 300, such as relative to the inlet 304 and/or the outlet 306 of the shell 300. In particular, the respective distance 342 between adjacent baffles 308 may be increased the closer the associated, adjacent baffles 308 are to the inlet 304 and/or may be decreased the closer the associated, adjacent baffles 308 are to the outlet 306.

[0072] The spacings or distances 342 between different adjacent baffles 308 may be selected to enable improved heat transfer from the flow of heated fluid 182 to the mixture of lubricant and working fluid 180. As the mixture of lubricant and working fluid 180 is directed through the shell 300, heat is transferred from the flow of heated fluid 182 within the plurality of tubes 302 to the mixture of lubricant and working fluid 180. In this way, liquid working fluid within the mixture of lubricant and working fluid 180 may vaporize and separate from the lubricant within the mixture of lubricant and working fluid 180. Indeed, the evaporated working fluid 186 may rise within the shell 300, such that the separated lubricant 184 remains at a base or bottom portion of the shell 300. Therefore, a volume of fluid (e.g., mixture of lubricant and working fluid 180) remaining at a base or bottom portion of the shell 300 may decrease as the mixture of lubricant and working fluid 180 flows from the inlet 304 to the outlet 306. The decrease in volume of fluid at the bottom of the shell 300 may cause a height of the fluid to reduce within the shell 300, which may otherwise result in portions of certain tubes 302 proximate the outlet 306 and/or the second end 336 of the shell 300 to not be submerged within the liquid and thereby reduce efficiency of heat transfer from the heated fluid 182 to the mixture 180 at such portions of the tubes 302 adjacent the second end 336 of the shell 300. By decreasing the distances 342 between adjacent baffles 308 that are positioned closer to the outlet 306 and/or the second end 336 of the shell 300, the adjacent baffles 308 may function to maintain a greater height of the fluid directed along the serpentine flow path 310 at or near the outlet 306 and/or the second end 336 of the shell 300. In this way, the variable distances 342 (e.g., variable longitudinal spacings) between adjacent baffles 308 may enable improved heat transfer from the heated fluid 182 to the mixture 180 across an entirety of the length 311 of the shell 300.

[0073] FIG. 11 is a cross-sectional schematic side view of an embodiment of the lubricant separation heat exchanger 118 of the lubricant separation system 112, in accordance with an aspect of the present disclosure. The illustrated embodiment includes similar elements and element numbers as those described above with reference to FIG. 10. For example, the lubricant separation heat exchanger 118 includes the shell 300 with the plurality of tubes 302 extending therethrough. The lubricant separation heat exchanger 118 also includes the first manifold 320, the second manifold 334, and the baffles 308 disposed within the shell 300 (e.g., with variable spacing distances 342 therebetween). Thus, the illustrated lubricant separation heat exchanger 118 may operate in a manner similar to that described above.

[0074] The illustrated embodiment also includes the inlet 304 of the shell 300 configured to receive the mixture of lubricant and working fluid 180 from the evaporator 110 and the outlet 306 of the shell 300 configured to discharge the separated lubricant 184 from the shell 300. The inlet 304 of the shell 300 may be configured to receive the mixture of lubricant and working fluid 180 from the flooded section 192 of the evaporator 110, such as via force of gravity. Additionally, the separated lubricant 184 may be directed from the lubricant separation heat exchanger 118 toward the eductor 130 and/or the lubricant reservoir 116.

[0075] The lubricant separation heat exchanger 118 further includes a first working fluid outlet 360 and a second working fluid outlet 362. The first working fluid outlet 360 and the second working fluid outlet 362 are each configured to discharge working fluid from the shell 300 of the lubricant separation heat exchanger 118 (e g., toward the evaporator 110). The lubricant separation heat exchanger 118 may include the first working fluid outlet 360 and the second working fluid outlet 362 to enable proper, desired, and/or efficient flow of the mixture of lubricant and working fluid 180 from the evaporator 110 and into the shell 300 and proper, desired, and/or efficient flow of working fluid (e.g., separated from lubricant) out of the shell 300 and to the evaporator 110, as described in further detail below. In some embodiments, the inlet 304 and the first working fluid outlet 360 may be positioned along the shell 300 at a generally common axial location along the length 311 of the shell 300.

[0076] FIG. 12 is a schematic of an embodiment of the evaporator 110 of the working fluid circuit 102 and the lubricant separation heat exchanger 118 of the lubricant separation system 112, illustrating fluid connections between the evaporator 110 and the lubricant separation heat exchanger 118. The lubricant separation heat exchanger 118 includes similar elements and element numbers as those discussed above with reference to FIG. 12. For example, the lubricant separation heat exchanger 118 includes the shell 300, the plurality of tubes 302, the inlet 304, the outlet 306, the baffles 308, the first working fluid outlet 360, and the second working fluid outlet 362. Further, the evaporator 110 may be a hybrid falling film evaporator having the shell 188 with the falling film section 190 and the flooded section 192 disposed therein, as similarly discussed above. [0077] The inlet 304 of the shell 300 may be fluidly coupled to the flooded section 192 of the evaporator 110 via an inlet conduit 400 and may be configured to receive the mixture of lubricant and working fluid 180 from the evaporator 110 via force of gravity. In some embodiments, the inlet conduit 400 may be fluidly coupled to the shell 188 of the evaporator 110 at a location away from a suction port of the evaporator 110. As mentioned above, the first working fluid outlet 360 and the second working fluid outlet 362 may each be configured to direct working fluid (e.g., evaporated working fluid 186) from the lubricant separation heat exchanger 118 to the evaporator 110. For example, the lubricant separation system 112 may include a first outlet conduit 402 extending from the first working fluid outlet 360 (e.g., proximate the first end 322) to the evaporator 110. In particular, the first outlet conduit 402 may be fluidly coupled to the shell 188 of the evaporator 110 a first inlet location 404 positioned above the flooded section 192 of the evaporator 110 (e.g., relative to a vertical axis 406, relative to a direction gravity). As will be appreciated, the first working fluid outlet 360 and the first outlet conduit 402 may be configured to direct evaporated working fluid 186 that initially evaporates and separates from the mixture of lubricant and working fluid 180 (e.g., proximate the inlet 304) within the shell 300 to flow back to the evaporator 110. In this way, pressures within the shell 300 of the lubricant separation heat exchanger 118 and within the shell 188 of the evaporator 110 may be more balanced and/or equalized, which may facilitate proper flow of the mixture of lubricant and working fluid 180 into the lubricant separation heat exchanger 118 from the evaporator 110.

[0078] The lubricant separation system 112 may also include a second outlet conduit 408 extending from the second working fluid outlet 362 (e.g., proximate the second end 366) to the evaporator 110. In particular, the second outlet conduit 408 may be fluidly coupled to the shell 188 of the evaporator 110 at a second inlet location 410 that is positioned above the first inlet location 404 (e.g., relative to the vertical axis 406, relative to a direction gravity) associated with the first outlet conduit 402 of the evaporator 110 In some embodiments, the second inlet location 410 may be located proximate an outlet 412 (e.g., section outlet, vapor outlet) of the evaporator 110. As will be appreciated, pressures within the shell 188 near the second inlet location 410 may be less than pressures within the shell 188 near the first inlet location 404. The reduced pressures within the shell 188 near the second inlet location 410 may facilitate flow of the evaporated working fluid 186 out of the lubricant separation heat exchanger 118 and into the evaporator 110 via the second working fluid outlet 362 and the second outlet conduit 408 and may further facilitate flow of the evaporated working fluid 186 out of the evaporator 110 via the outlet 412.

[0079] FIGS. 13 are schematic axial views of embodiments of the evaporator 110 of the working fluid circuit 102 and the lubricant separation heat exchanger 118 of the lubricant separation system 112, illustrating fluid connections between the evaporator 110 and the lubricant separation heat exchanger 118. For example, the evaporator 110 may be a hybrid falling film evaporator, and the lubricant separation heat exchanger 118 may have a shell and tube configuration, as similarly discussed above.

[0080] The illustrated embodiments each show an embodiment of the first manifold 320 discussed above. Specifically, the embodiment of FIG. 13 illustrates the first manifold 320 having the inlet 324, the outlet 326, the first cavity 328, and the second cavity 330 with the first cavity 328 and the second cavity 330 separated by the partition 332. Thus, the lubricant separation heat exchanger 118 of FIG. 13 is configured to receive the flow of heated fluid 182 from a single heated fluid source (e.g., the lubricant reservoir 116).

[0081] The embodiment of FIG. 14 illustrates an embodiment of the first manifold 320 having a first inlet 420 fluidly coupled to a first inlet cavity 422, a first outlet 424 fluidly coupled to a first outlet cavity 426, a second inlet 428 fluidly coupled to a second inlet cavity 430, and a second outlet 432 fluidly coupled to a second outlet cavity 434. The lubricant separation heat exchanger 118 of FIG. 14 is therefore configured to direct a first flow of heated fluid 436 and a second flow of heated fluid 438 through the lubricant separation heat exchanger 118. Thus, the lubricant separation heat exchanger 118 may transfer heat to the mixture of lubricant and working fluid 180 to fluids from different heat sources (e.g., the cooling system 150 and the lubricant reservoir 116). Accordingly, the plurality of tubes 302 extending through the shell 300 may be associated with different fluids received from different heat sources. For example, the plurality of tubes 302 may be separated into a first group of tubes and a second group of tubes, where each group of tubes defines a respective first pass and second pass through the shell 300. The first group of tubes may be configured to receive the first flow of heated fluid 436 via the first inlet 420 and the first inlet cavity 422 and to discharge the first flow of heated fluid 436 via the first outlet 424 and the first outlet cavity 426. The first inlet cavity 422 and the first outlet cavity 426 may be separated by a first partition 440. Similarly, second group of tubes may be configured to receive the second flow of heated fluid 438 via the second inlet 428 and the second inlet cavity 430 and to discharge the second flow of heated fluid 438 via the second outlet 432 and the second outlet cavity 434. The second inlet cavity 430 and the second outlet cavity 434 may be separated by a second partition 442. Further, the first outlet cavity 426 and the second inlet cavity 430 may be separated by a third partition 444. In this way, the lubricant separation heat exchanger 118 may enable more versatile operation and separation of working fluid from lubricant.

[0082] While only certain features and embodiments of the present disclosure have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or resequenced according to alternative embodiments, ft is, therefore, to be noted that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the present disclosure.

[0083] Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode of carrying out the present disclosure, or those unrelated to enabling the claimed embodiments). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

[0084] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function], ..” or “step for [perform]ing [a function]...”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).