Lubricant separation system for hvacr system

Abstract

The present invention provides a method for heating, ventilation, air conditioning and refrigeration (HVACamp; a system (R, R) 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 lubricant from the evaporator and to transfer heat from the heated fluid stream to the mixture to separate the working fluid from the lubricant. The lubricant separation system is further configured to direct the working fluid separated from the lubricant to the evaporator.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 404,814, filed on September 8, 2022, entitled “OIL PURIFIER FOR AN HVAC SYSTEM,” which is incorporated herein by reference in its entirety for all purposes. Background Art

[0003] This section is intended to introduce the reader to various aspects of the technology that may be related to various aspects of the present disclosure described below. It is believed that this discussion helps to provide the reader with background information to promote a better understanding of various aspects of the present disclosure. Therefore, it should be understood that these statements should be read in this light, rather than as an admission of the prior art.

[0004] Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems (such as vapor compression systems) utilize a working fluid (e.g., a refrigerant) that changes phase 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 a conditioning device and / or a conditioned environment served by the HVAC&R system. For example, the HVAC&R system may include a heat exchanger configured to receive a working fluid and a conditioning fluid to place the working fluid in a heat exchange relationship with the conditioning fluid. The conditioning fluid may be directed from the heat exchanger to other equipment, such as an air handler, 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, an HVAC&R system may include a lubrication system configured to supply lubricant to components of the HVAC&R system, such as a compressor. Unfortunately, the working fluid and the lubricant may mix or otherwise combine within the HVAC&R system, which may reduce the efficiency of the HVAC&R system. Summary of the invention

[0005] The following describes an overview of certain embodiments disclosed herein. It should be understood that these aspects are presented only to provide the reader with a brief overview of these specific embodiments, and these aspects are not intended to limit the scope of the present disclosure. In fact, the present disclosure may cover various aspects that may not be described below.

[0006] In one embodiment, a heating, ventilation, air conditioning and refrigeration (HVAC&R) system includes: an evaporator disposed along a working fluid circuit, wherein the evaporator is configured to transfer heat between the 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 working fluid and lubricant from the evaporator and transfer heat from the heated fluid stream 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.

[0007] 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 heated fluid stream received from a heated fluid source to separate the mixture into evaporated working fluid and separated lubricant. The lubricant separation heat exchanger includes a first inlet configured to receive the mixture from the evaporator, a second inlet configured to receive the heated fluid stream 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.

[0008] 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 the working fluid along the working fluid circuit; a lubricant reservoir configured to supply 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 evaporated working fluid and 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various aspects of the present disclosure may be better understood after reading the following detailed description and referring to the drawings, in which:

[0010] Figure 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 environment according to one aspect of the present disclosure;

[0011] Figure 2 is a perspective view of an embodiment of a vapor compression system according to one aspect of the present disclosure;

[0012] Figure 3 According to one aspect of the present disclosure Figure 2 A schematic diagram of an embodiment of a vapor compression system;

[0013] Figure 4 According to one aspect of the present disclosure Figure 2 A schematic diagram of an embodiment of a vapor compression system;

[0014] Figure 5 is a schematic diagram of an embodiment of an HVAC&R system including a working fluid circuit and a lubricant separation system according to one aspect of the present disclosure;

[0015] Figure 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 according to one aspect of the present disclosure;

[0016] Figure 7 is a cross-sectional schematic axial view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system according to one aspect of the present disclosure;

[0017] Figure 8 is a cross-sectional schematic top view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system according to one aspect of the present disclosure;

[0018] Fig. 9 is a cross-sectional schematic axial view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system according to one aspect of the present disclosure;

[0019] Fig.10 is a cross-sectional schematic top view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system according to one aspect of the present disclosure;

[0020] Fig.11 is a cross-sectional schematic side view of an embodiment of a lubricant separation heat exchanger of a lubricant separation system according to one aspect of the present disclosure;

[0021] Fig.12 is a schematic diagram of an embodiment of an evaporator of a working fluid circuit and a lubricant separation heat exchanger of a lubricant separation system according to one aspect of the present disclosure, the schematic diagram showing the fluid connection between the evaporator and the lubricant separation heat exchanger;

[0022] Fig.13 is a schematic axial view of an embodiment of an evaporator and a lubricant separation heat exchanger of a lubricant separation system of a working fluid circuit according to one aspect of the present disclosure, the schematic axial view showing fluid connections between the evaporator and the lubricant separation heat exchanger receiving a single heated source fluid; and

[0023] Fig.14 is a schematic axial view of an embodiment of an evaporator and a lubricant separation heat exchanger of a lubricant separation system of a working fluid circuit according to one aspect of the present disclosure, the schematic axial view showing the fluid connection between the evaporator and the lubricant separation heat exchanger receiving two heated source fluids. DETAILED DESCRIPTION

[0024] One or more specific embodiments will be described below. In order to provide a concise description of these embodiments, not all features of the actual implementation are described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, a large number of implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints, which may vary from implementation to implementation. In addition, it should be understood that such development work may be complex and time-consuming, but will be a routine task of design, production and manufacturing for ordinary technicians who benefit from this disclosure.

[0025] When introducing elements of various embodiments of the present disclosure, the articles "a," "an," and "the" are intended to indicate 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 in addition to 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 are further incorporated into the recited features.

[0026] As used herein, the terms "approximately," "substantially," "substantially," and the like are intended to convey that the value of the property being described may be within a relatively small range of that property value, as understood by one skilled in the art. 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, "substantially perpendicular" to another feature, and the like, this is intended to convey that the given feature is within + / -5%, within + / -4%, within + / -3%, within + / -2%, within + / -1%, or even closer of the described property, such as being parallel to another feature, being perpendicular to another feature, and the like. Mathematical terms, such as "parallel" and "perpendicular," should not be strictly interpreted in a strict mathematical sense, but rather should be interpreted as one of ordinary skill in the art would interpret such terms. For example, one of ordinary skill in the art will understand that two lines that are generally parallel to each other are largely parallel, but may have slight deviations from being completely parallel.

[0027] Embodiments of the present disclosure relate to a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system having a vapor compression system, such as a chiller or chiller system (such as a centrifugal chiller). A vapor compression system (e.g., a vapor compression loop) can circulate a working fluid (e.g., a heat transfer fluid, a refrigerant) through a working fluid loop to cool and / or heat a conditioning fluid (e.g., water). The HVAC&R system can then direct the conditioning fluid to other equipment to condition the spaces and / or components served by the HVAC&R system. The vapor compression system can 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 a conditioning fluid). For example, the vapor compression system can include an evaporator configured to place the working fluid in a heat exchange relationship with the conditioning fluid to effect heat transfer from the conditioning fluid to the working fluid to cool the conditioning fluid (e.g., reduce the temperature of the conditioning fluid).

[0028] The vapor compression system may also include a compressor (e.g., a compressor system, a centrifugal compressor) arranged along a working fluid circuit. The compressor may be operated to drive or force a working fluid to flow along a 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, which are configured to rotate during operation of the compressor. To this end, the compressor may also include one or more bearings, which are configured to enable components of the compressor (such as the shaft of the compressor) to rotate and / or contribute to its rotation. The bearing may have any suitable configuration or design, and may include, for example, magnetic bearings, roller bearings, ball bearings, bearing surfaces, fluid bearings, static pressure bearings, fluid dynamic bearings, radial bearings, thrust bearings, active bearings, passive bearings, another type of bearing, or any combination thereof. In some embodiments, the bearing may utilize a lubricant (e.g., oil) to help improve the rotation of one or more components of the compressor. Unfortunately, in some existing systems, a certain amount (e.g., a portion) of lubricant supplied to the compressor may be mixed with the working fluid circulated by the compressor. In some cases, 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 use with 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 the working fluid evaporates within the evaporator. Unfortunately, the lubricant that is collected for return to the compressor may include residual amounts of working fluid entrained within the lubricant, which may reduce the effectiveness of the lubricant in lubricating components within the compressor.

[0029] Therefore, it is now recognized that it is desirable to separate working fluid (e.g., refrigerant) and lubricant (e.g., oil) from improved systems and methods in a vapor compression system. Therefore, the present disclosure relates to a lubricant separation system for a vapor compression system. The lubricant separation system is configured to enable improved separation of working fluid and lubricant mixed together in a working fluid circuit of a vapor compression system. Specifically, the lubricant separation system includes a heat exchanger configured to receive a mixture of lubricant and working fluid collected in a working fluid circuit (such as collected in an evaporator of the working fluid circuit). The heat exchanger can also receive a heated fluid, such as a heated lubricant, and the heated fluid can be placed in a heat exchange relationship with the mixture of lubricant and working fluid. In particular, the heat exchanger can enable heat to be transferred from the heated fluid to the mixture of lubricant and working fluid. In this way, the working fluid in the mixture of lubricant and working fluid can evaporate and thereby be separated from the lubricant. The evaporated working fluid can be directed back to the evaporator or other suitable part of the working fluid circuit, and the lubricant can be directed back to the compressor to be used as a lubricating fluid. By enabling improved separation of mixed working fluid and lubricant, the present technology enables improved operation of a vapor compression system. For example, the lubricant directed back to the compressor may be more concentrated and may be better used to lubricate components within the compressor. Additionally, the working fluid circulating through the working fluid loop may include less lubricant mixed therein, which may increase the efficiency of the vapor compression loop.

[0030] Turning now to the accompanying drawings, Figure 1 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 environment. The HVAC&R system 10 may include a vapor compression system 14 (e.g., a chiller) that supplies a cooling liquid that can be used to cool the building 12. The HVAC&R system 10 may also include a boiler 16 for supplying warm liquid to heat the building 12 and an air distribution system that circulates air through the building 12. The air distribution system may also include air return ducts 18, air supply ducts 20, and / or air handlers 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 via ducts 24. Depending on the operating mode of the HVAC&R system 10, the heat exchanger in the air handler 22 may receive heated liquid from the boiler 16 or cooled liquid from the vapor compression system 14. The HVAC&R system 10 is shown with separate air handlers on each floor of the 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 floors.

[0031] Figure 2 and 3 is an embodiment of a vapor compression system 14 that may 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 that begins with a compressor 32. The circuit may also include a condenser 34, an expansion valve or device 36, and a liquid cooler or evaporator 38. The vapor compression system 14 may further include a control panel 40 having an analog-to-digital (A / D) converter 42, a microprocessor 44, a non-volatile memory 46, and / or an interface board 48.

[0032] Some examples of fluids that can be used as working fluids in the vapor compression system 14 are hydrofluorocarbon (HFC) based refrigerants (e.g., R-410A, R-407, R-134a, R-1234ze, R1233zd, hydrofluoroolefins (HFO)), "natural" refrigerants (such as 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 can be configured to effectively utilize a working fluid having a normal boiling point of about 19 degrees Celsius (66 degrees Fahrenheit) at one atmosphere of pressure, also referred to as a low pressure working fluid relative to a medium pressure working fluid (such as R-134a). As used herein, "normal boiling point" can refer to the boiling point temperature measured at one atmosphere of pressure.

[0033] In some embodiments, the vapor compression system 14 may use one or more of a variable speed drive (VSD) 52, a motor 50, a compressor 32, a condenser 34, an expansion valve or device 36, and / or an evaporator 38. The motor 50 may drive the compressor 32 and may be powered by the variable speed drive (VSD) 52. The VSD 52 receives AC power having a specific fixed line voltage and a fixed line frequency from an alternating current (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 by an AC or direct current (DC) power source. The motor 50 may include any type of motor that may be powered by a VSD or directly by 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.

[0034] The compressor 32 compresses the working fluid vapor and delivers the vapor to the condenser 34 through the exhaust passage. In some embodiments, the compressor 32 may be a centrifugal compressor. The working fluid vapor delivered to the condenser 34 by the compressor 32 may transfer heat to a cooling fluid (e.g., water or air) in the condenser 34. Due to the heat transfer with the cooling fluid, the working fluid vapor may condense into a working fluid liquid in the condenser 34. The liquid working fluid from the condenser 34 may flow to the evaporator 38 through the expansion device 36. Figure 3 In the illustrated embodiment of , the condenser 34 is water-cooled and includes a tube bundle 54 connected to a cooling tower 56 that supplies cooling fluid to the condenser 34 .

[0035] The liquid working fluid delivered to the evaporator 38 may absorb heat from the 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 liquid working fluid to working fluid vapor. Figure 3 As shown in the illustrated embodiment of , 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. A conditioning fluid (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) for the evaporator 38 enters the evaporator 38 via the return line 60R and exits the evaporator 38 via the supply line 60S. The evaporator 38 may reduce the temperature of the conditioning fluid in the tube bundle 58 by heat transfer with the working fluid. The tube bundle 58 in the evaporator 38 may include multiple tubes and / or multiple tube bundles. In any case, the vapor working fluid exits the evaporator 38 and returns to the compressor 32 via the suction line to complete the cycle.

[0036] Figure 4 is a schematic diagram of vapor compression system 14 in which intermediate loop 64 is coupled between condenser 34 and expansion device 36. Intermediate loop 64 may have an inlet line 68 directly fluidly connected to condenser 34. In other embodiments, inlet line 68 may be indirectly fluidly coupled to condenser 34. Figure 4 In the illustrated embodiment, 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." Figure 4 In the illustrated embodiment, the intermediate vessel 70 is used as a flash tank, and the first expansion device 66 is configured to reduce 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.

[0037] In addition, the intermediate container 70 can provide further expansion of the liquid working fluid due to the pressure drop experienced by the liquid working fluid when entering the intermediate container 70 (e.g., due to the rapid increase in volume experienced when entering the intermediate container 70). The vapor in the intermediate container 70 can be drawn by the compressor 32 through the suction line 74 of the compressor 32. In other embodiments, the vapor in the intermediate container can be drawn to an intermediate stage (e.g., a non-suction stage) of the compressor 32. Due to the expansion in the expansion device 66 and / or the intermediate container 70, the liquid collected in the intermediate container 70 can be at a lower enthalpy than the liquid working fluid leaving the condenser 34. The liquid from the intermediate container 70 can then flow in line 72 through the second expansion device 36 to the evaporator 38.

[0038] It should be understood that any of the features described herein can be combined with the vapor compression system 14 or any other suitable HVAC&R system. For example, the present technology can be combined with any HVAC&R system having an economizer (such as the intermediate container 70) and a compressor (such as the compressor 32). The following discussion describes the present technology in combination with an embodiment of the compressor 32 configured as a single-stage compressor. However, it should be noted that the systems and methods described herein can be combined with other embodiments of the compressor 32 and the HVAC&R system 10.

[0039] Considering the foregoing, Figure 5 1 is a schematic diagram 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 described above. For example, the HVAC&R system 100 includes a working fluid circuit 102 (e.g., a vapor compression circuit) having a compressor system 104, a condenser 106, and an expansion valve 108, and an evaporator 110. The working fluid circuit 102 can 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.

[0040] 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 described 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. Accordingly, the HVAC system 100 may be configured to supply 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, a certain amount of lubricant supplied to the compressor system 104 may mix with the working fluid circulated through the working fluid circuit 102 by the compressor system 104. In some cases, the lubricant mixed with the working fluid can be directed along the working fluid circuit 102 toward other components of the working fluid circuit 102, such as the evaporator 110. In fact, in some applications, the lubricant mixed with the working fluid can be collected within certain components of the working fluid circuit 102. Therefore, the present embodiment includes a lubricant separation system 112 that is configured to enable improved separation of lubricant and working fluid that are mixed together within the HVAC&R system 100. In the manner described below, the working fluid and the lubricant can be separated from each other and can be separately directed to appropriate portions or components of the HVAC&R system 100.

[0041] In the illustrated embodiment, the lubricant separation system 112 includes a lubricant separation heat exchanger 118, which is configured to enable separation of lubricant from a working fluid that is mixed together within the working fluid circuit 102 (e.g., within the compressor system 104). The configuration 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 components 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 a portion of the lubricant and the liquid working fluid collected within the evaporator 110.

[0042] The lubricant separation heat exchanger 118 is also configured to receive a heated fluid stream and place the heated fluid stream in a heat exchange relationship with the mixture of lubricant and working fluid. The heated fluid stream can be any suitable heated fluid supplied by any suitable source. For example, the heated fluid stream can be a heated lubricant stream supplied by the lubricant reservoir 116, as indicated by arrow 122. In some embodiments, the heated lubricant stream can 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 can include a heater 126 (e.g., a heating element) that is 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 can be configured to place the heated lubricant in a heat exchange relationship (e.g., a fluidly separated heat exchange relationship) with the mixture of the lubricant and the working fluid to enable heat to be transferred from the heated lubricant to the mixture of the lubricant and the working fluid. As a result, the liquid working fluid mixed with the lubricant may evaporate and separate from the lubricant. Thereafter, the evaporated working fluid may be directed from the lubricant separation heat exchanger 118 back to the evaporator 110 by the lubricant separation system 112, as indicated by arrow 128.

[0043] The lubricant remaining in the lubricant separation heat exchanger 118 from the initial mixture of lubricant and working fluid can be directed back to the lubricant reservoir 116. In some embodiments, the separated and / or concentrated lubricant in the lubricant separation heat exchanger 118 can be directed by the lubricant separation system 112 toward an ejector 130 (e.g., a jet pump, an ejector, a vacuum pump), as indicated by arrow 132 (e.g., a conduit). The ejector 130 can receive the separated and / or concentrated lubricant from the lubricant separation heat exchanger 118 as an inlet or suction fluid. The ejector 130 can also receive a motive fluid flow to enable a pressure differential or vacuum to be generated within the ejector 130, and thereby cause the ejector 130 to draw the separated and / or concentrated lubricant from the lubricant separation heat exchanger 118 into the ejector 130. In some embodiments, the motive fluid supplied to the ejector 130 may be a high pressure working fluid gas or vapor (e.g., pressurized fluid) directed to the ejector 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 compressor 114 may include a first compressor 136 (e.g., a first stage compressor, a low stage compressor) and a second compressor 138 (e.g., a second stage compressor, a high stage compressor) arranged in series (e.g., relative to the flow of the working fluid through the compressor system 104), and the pressurized working fluid gas may be directed to the ejector 130 from the discharge of the first compressor 136. However, in other embodiments, the motive fluid supplied to the ejector 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 pressurized fluid source.

[0044] In the illustrated embodiment, the ejector 130 is configured to direct the mixture of concentrated lubricant and high-pressure working fluid gas to the lubricant reservoir 116. As will be appreciated, the concentrated lubricant and high-pressure working fluid gas may not easily mix within the ejector 130 and / or the lubricant reservoir 116. Therefore, the high-pressure working fluid gas can be directed back to the compressor system 104 (e.g., directed to the second compressor 138) to mix with the working fluid directed along the working fluid circuit 102, as indicated by arrow 140. The working fluid of the lubricant reservoir 116 from the ejector 130 can be evaporated into a working fluid vapor by absorbing heat from the heated lubricant in the lubricant reservoir 116, and can 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 the arrows, for use in reconditioning (e.g., cooling) and subsequently for lubricating components of the compressor system 104, as indicated by arrow 144. Although the present discussion describes concentrated lubricant returning from the lubricant separation heat exchanger 118 to the lubricant reservoir 116 via operation of the ejector 130, it should be understood that the lubricant separation system 112 may include additional or alternative components to enable separated lubricant to flow 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 separated and / or concentrated lubricant to flow from the lubricant separation heat exchanger 118 to the lubricant reservoir 116.

[0045] Returning to the discussion of the operation of the lubricant separation heat exchanger 118, the temperature of the heated lubricant directed through the lubricant separation heat exchanger 118 as a heated fluid may be reduced because 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 also function as a cooling system for the lubricant within the lubricant reservoir 116. Thus, certain embodiments of the HVAC&R system 100 may not include a separate and / or dedicated cooling system to cool the lubricant within the lubricant reservoir 116 received from the compressor system 104. Additionally or alternatively, the HVAC&R system 100 may include a lubricant cooling system that operates at a reduced power consumption. The lubricant directed through the lubricant separation heat exchanger 118 as a heated fluid may be discharged by the lubricant separation heat exchanger 118 and directed from the lubricant separation heat exchanger 118 to the compressor system 104 (e.g., through the lubricant separation system 112) for use with components (such as bearings) of the lubricating compressor system 104, as indicated by arrows 146 (e.g., conduits). That is, in some embodiments, the lubricant used as a heated fluid within the lubricant separation heat exchanger 118 may not be directed back to the lubricant reservoir 116.

[0046] In further embodiments, the lubricant separation system 112 may utilize an additional or alternative fluid as the heated fluid to enable heat to be transferred 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., a controller, an automation controller, a control board) that includes and / or utilizes a cooling system 150 that is configured to cool one or more electronic components of the control system 148.

[0047] In some embodiments, the control system 148 may include a processing circuit system 152, such as a microprocessor, which may execute software for controlling the components of the HVAC&R system 100. The processing circuit system 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 circuit system 152 may include one or more reduced instruction set (RISC) processors. The control system 148 may also include a memory device 154 (e.g., memory), which may store information such as instructions, control software, lookup tables, configuration data, etc. The memory device 154 may include volatile memory, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM). The memory device 154 may store a variety of information and may be used for a variety of purposes. For example, the memory device 154 may store processor-executable instructions including firmware or software for execution by the processing circuit system 152, such as instructions for controlling the components of the HVAC&R system 100. In some embodiments, the memory device 154 is a tangible, non-transitory machine-readable medium that can store machine-readable instructions for execution by the processing circuit system 152. The memory device 154 can include a ROM, a flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The memory device 154 can store data, instructions, and any other suitable data. In addition, the control system 148 can include a variable speed drive (VSD) 156, which can be configured to operate one or more compressors in the compressor 114 at a variable speed, as similarly discussed above.

[0048] In some embodiments, the cooling system 150 can circulate a cooling fluid (e.g., water, ethylene glycol, a mixture of water and ethylene glycol) and place the cooling fluid in heat exchange relationship with one or more components of the control system 148 (such as the VSD 156). In this manner, the cooling fluid circulated by the cooling system 150 can absorb heat from components of the control system 148 (e.g., electrical components). As the cooling fluid absorbs heat from components of the control system 148 (e.g., electrical components), the cooling fluid may become hot. Thus, the cooling fluid may be suitable for use as a heated fluid directed through the lubricant separation heat exchanger 118. Thus, the control system 148 (e.g., the cooling system 150, the heated fluid source) can be configured to direct the cooling fluid to the lubricant separation heat exchanger 118 after the cooling fluid absorbs heat from components of the control system 148, as indicated by arrow 158. Within the lubricant separation heat exchanger 118, the cooling fluid may transfer heat to the mixture of lubricant and working fluid, thereby reducing the 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. Thus, the cooling fluid may be directed from the lubricant separation heat exchanger 118 back to the cooling system 150, as indicated by arrow 160.

[0049] Additionally or alternatively, the lubricant separation system 112 can utilize a working fluid stream as a heated fluid to enable heat to be transferred to a mixture of lubricant and working fluid within the lubricant separation heat exchanger 118. For example, as indicated by arrow 162, a working fluid stream (e.g., a heated working fluid, a condensed working fluid) can be directed from the condenser 106 (e.g., a heated fluid source) to the lubricant separation heat exchanger 118. Within the lubricant separation heat exchanger 118, heat can be transferred from the working fluid stream to the mixture of lubricant and working fluid (e.g., to vaporize the working fluid within the mixture). In this manner, the lubricant separation heat exchanger 118 can operate to subcool and / or further subcool the working fluid stream used as a heated fluid. Thereafter, the working fluid stream used as a heated fluid can 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.

[0050] Figure 61 is a schematic axial view of an embodiment of an evaporator 110 and a lubricant separation heat exchanger 118 of a lubricant separation system 112 of a working fluid circuit 102 according to one aspect of the present disclosure. As discussed above, the lubricant separation heat exchanger 118 is configured to receive a mixture 180 of lubricant and working fluid from the evaporator 110 and receive a heated fluid 182 stream, such as a heated lubricant stream, to enable heat to be transferred from the heated fluid stream to the mixture of lubricant and working fluid. When heat is transferred to the mixture of lubricant and working fluid, the liquid working fluid within the mixture may evaporate and separate from the lubricant within the mixture, which may remain in a liquid phase. In this manner, the lubricant may become a concentrated and / or separated lubricant 184, which may be discharged from the lubricant separation heat exchanger 118 and directed toward a lubricant reservoir 116 (e.g., an ejector 130) for use in lubricating components of the compressor system 104. The evaporated (eg, vaporized, separated) working fluid 186 separated from the lubricant may be directed from the lubricant separation heat exchanger 118 back to the evaporator 110 .

[0051] In some embodiments, the evaporator 110 can be a hybrid falling film evaporator. That is, the evaporator 110 may include a shell 188 (e.g., a housing) in which a falling film portion 190 and an overflow portion 192 are provided. The falling film portion 190 may be vertically disposed above the overflow portion 192 relative to the direction of gravity. The falling film portion 190 and the overflow portion 192 may each include a plurality of corresponding tubes extending therethrough and configured to circulate the conditioning fluid. As will be appreciated, the liquid working fluid in the shell 188 of the evaporator 110 may be collected in the overflow portion 192 of the evaporator 110. The lubricant in the shell 188 of the evaporator 110 (such as the lubricant of the working fluid flow that initially enters the compressor system 104) may also be collected in the overflow portion 192. Therefore, a mixture of the liquid working fluid and the lubricant may be collected and / or accumulated in the overflow portion 192 of the evaporator 110. Thus, the lubricant separation system 112 may include a first conduit 194 (e.g., an inlet conduit, a first inlet conduit) extending from an overflow portion 192 (e.g., housing 188) to the lubricant separation heat exchanger 118, wherein the first conduit 194 is configured to direct the mixture 180 of lubricant and working fluid from the evaporator 110 to the lubricant separation heat exchanger 118, such as via 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 ejector 130. In addition, 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 the top of the lubricant separation heat exchanger 118 to the shell 188 at and / or near the falling film portion 190 of the evaporator 110 .

[0052] To enable heat exchange between the mixture 180 of lubricant and working fluid and the stream of heated fluid 182, the lubricant separation heat exchanger 118 may include a heat transfer device 200 (e.g., a heat transfer device, a heat transfer block, a heat transfer assembly) configured to place the mixture 180 of lubricant and working fluid and the stream of heated fluid 182 in heat exchange relationship with each other. As discussed in further detail below, the heat transfer device 200 may also be positioned within a housing 202 of the lubricant separation heat exchanger 118 in a manner that maintains fluid separation of the mixture 180 of lubricant and working fluid from the stream of heated fluid 182 within the lubricant separation heat exchanger 118. As also described further below, the mixture 180 of lubricant and working fluid directed into the housing 202 by the first conduit 194 may flow through and / or across the heat transfer device 200 toward the first outlet conduit 196.

[0053] In some embodiments, the lubricant separation heat exchanger 118 may include a first header 204 (e.g., a first manifold) configured to direct the heated fluid 182 flow into the heat transfer device 200, and a second header 206 (e.g., a second manifold) configured to receive the heated fluid 182 flow from the heat transfer device 200 and discharge the heated fluid 182 flow from the lubricant separation heat exchanger 118. In some embodiments, the first conduit 194, the first outlet conduit 196, the heat transfer device 200, the first header 204, and / or the second header 206 may be arranged such that the mixture 180 of lubricant and working fluid and the heated fluid 182 flow are directed through the heat transfer device 200 in a counter-flow arrangement. In this manner, heat transfer between the mixture 180 of lubricant and working fluid and the heated fluid 182 flow may be improved, thereby increasing separation of the working fluid from the lubricant within the lubricant separation heat exchanger 118.

[0054] Figure 7is a cross-sectional schematic axial view of an embodiment of a lubricant separation heat exchanger 118 of a lubricant separation system 112 according to one aspect of the present disclosure. As described above, the lubricant separation heat exchanger 118 includes a heat transfer device 200 disposed within a housing 202 of the lubricant separation heat exchanger 118. In the illustrated embodiment, the heat transfer device 200 includes a block structure 220 that defines a plurality of channels 222 extending through the block structure 220. The plurality of channels 222 may extend in series or sequentially from a first side 224 of the block structure 220 to a second side 226 of the block structure 220. Thus, the plurality of channels 222 may 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, bosses, etc.) extending (e.g., extending vertically) 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, such as Figure 8 shown.

[0055] The block structure 220 can be positioned within the housing 202 of the lubricant separation heat exchanger 118 to separate a first cavity 232 (e.g., an inlet portion, an intake cavity) within the housing 202 from a second cavity 234 (e.g., an outlet portion, an exhaust cavity) within the housing 202. During operation of the lubricant separation heat exchanger 118, the mixture 180 of lubricant and working fluid can be directed into the housing 202 via an inlet 236 of the lubricant separation heat exchanger 118, which can be fluidly coupled to the first conduit 194. Specifically, the mixture 180 of lubricant and working fluid can be directed from the inlet 236 into the first cavity 232. From the first cavity 232, the mixture 180 of lubricant and working fluid can flow from the first side 224 of the block structure 220 through the plurality of channels 222 to the second side 226 of the block structure 220. In practice, the lubricant separation heat exchanger 118 can be configured to prevent the mixture of lubricant and working fluid 180 from flowing 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 can include one or more seals (e.g., sealing elements, gaskets, barrier elements, sealing members) configured to prevent the mixture of lubricant and working fluid 180 from flowing around the block structure 220, such as between the block structure 220 and the housing 202. In the illustrated embodiment, the lubricant separation heat exchanger 118 includes a base seal 238 positioned between the housing 202 and the base portion 230 of the block structure 220 to prevent the mixture of lubricant and working fluid 180 from flowing therebetween. The lubricant separation heat exchanger 118 can include additional or alternative seals, as described below with reference to Figure 8 described.

[0056] The heat transfer device 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 are vertically arranged within the plurality of channels 222. Each tube 240 is configured to direct a heated fluid through each tube. 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.

[0057] During operation of the lubricant separation heat exchanger 118, the mixture 180 of lubricant and working fluid may flow from the first cavity 232 within the housing 202 through the plurality of channels 222 and toward the second cavity 234 within the housing 202, while the heated fluid 182 stream may flow through the plurality of tubes 240 extending within the plurality of channels 222. When the mixture 180 of lubricant and working fluid and the heated fluid 182 stream are directed through the heat transfer device 200 in this manner, heat may be transferred from the heated fluid 182 stream to the mixture 180 of lubricant and working fluid, thereby causing the liquid working fluid within the mixture 180 to evaporate. As indicated by arrows 246, the evaporated working fluid 186 may separate from the lubricant within the mixture 180 and rise (e.g., flow upward) within the plurality of channels 222 toward an outlet 248 of the lubricant separation heat exchanger 118 (e.g., housing 202). Thus, the mixture 180 of lubricant and working fluid can be separated into vaporized working fluid 186 and separated lubricant 184, and the separated lubricant 184 can be collected and / or accumulated within the second cavity 234 of the housing 202. The separated lubricant 184 can flow from the second cavity 234 through an outlet 250 of the housing 202, which can be fluidly coupled to the first outlet conduit 196 to be discharged from the lubricant separation heat exchanger 118.

[0058] The components of the lubricant separation heat exchanger 118 (e.g., the heat transfer device 200) can be formed from any suitable material and utilize any suitable process. For example, the block structure 220 can be formed from a polymer (e.g., plastic) and / or a metallic material (e.g., aluminum) and can be formed via injection molding, machining, cutting, additive manufacturing (e.g., 3D printing), and / or other suitable processes. Similarly, a seal (e.g., a base seal 238) disposed between the block structure 220 and the housing 202 can be formed from any suitable material (such as plastic, metal, a compressible material, foam, a polymer, and / or other suitable material). In fact, the components of the lubricant separation heat exchanger 118 described herein can be formed from any suitable material that is compatible with the working fluid and lubricant utilized by the HVAC&R system 100.

[0059] Figure 8 is a cross-sectional schematic top view of an embodiment of a lubricant separation heat exchanger 118 of a lubricant separation system 112 according to one aspect of the present disclosure. The illustrated embodiment includes the same Figure 7The lubricant separation heat exchanger 118 includes a heat transfer device 200 having a block structure 220 and a plurality of tubes 240 disposed within a housing 202 of the lubricant separation heat exchanger 118. A plurality of channels 222 defined by a plurality of extensions 228 of the block structure 220 cooperatively form a serpentine flow path 260 through the block structure 220 (e.g., from a first cavity 232 to a second cavity 234 within the housing 202). In addition, the plurality of tubes 240 extend through the housing 202 and along the serpentine flow path 260. Thus, a heated fluid 182 flow can be directed through the plurality of tubes 240 to transfer heat to a mixture 180 of lubricant and working fluid within the serpentine flow path 260 to enable separation of the mixture 180 into an evaporated working fluid 186 and a concentrated lubricant 184.

[0060] The illustrated embodiment also includes an additional seal 262 positioned within the housing 202 to separate the first cavity 232 from the second cavity 234. That is, similar to the base seal 238, the additional seal 262 is configured to prevent the mixture 180 of lubricant and working fluid from flowing along the serpentine flow path 260 and flowing directly from the first cavity 232 to the second cavity 234. The additional seal 262 can be incorporated into the lubricant separation heat exchanger 118 in combination with the base seal 238 discussed above. The additional seal 262 includes a first end seal 264 and a second end seal 266 positioned at respective longitudinal ends 268 of the housing 202 (e.g., the block structure 220) relative to the 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 the first end plate 272 of the housing 202, and the second end seal 266 may be disposed between the block structure 220 and the second end plate 274 of the housing 202. During assembly and / or manufacture of the lubricant separation heat exchanger 118, the additional seal 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 the body 276 of the housing 202. In this manner, the additional seal 262 may be secured (e.g., captured, wedged) between the block structure 220 and the housing 202 to create a sealing joint (e.g., a fluid seal, a fluid barrier) that may prevent the mixture 180 of lubricant and working fluid from flowing directly 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.

[0061] Fig. 91 is a cross-sectional schematic axial view of an embodiment of a lubricant separation heat exchanger 118 of a lubricant separation system 112 according to one aspect of the present disclosure. As similarly described above, the lubricant separation heat exchanger 118 includes a housing 202, an inlet 236 configured to receive the mixture 180 of lubricant and working fluid from the evaporator 110, an outlet 250 configured to discharge the concentrated lubricant 184, and an outlet 248 configured to discharge the evaporated working fluid 186.

[0062] The illustrated embodiment also includes an alternative embodiment of the heat transfer device 200, referred to herein as a heat transfer device 280. Specifically, the heat transfer device 280 includes an alternative embodiment of the block structure 220, which includes a base portion 230 and a plurality of extensions 228 extending (e.g., extending vertically) from the base portion 230 to define the plurality of channels 222 discussed above. The plurality of extensions 228 include a plurality of ports 282 (e.g., passages, flow paths, cavities) formed therein. The plurality of ports 282 are configured to circulate the heated fluid 182 flow through the plurality of ports so that the heated fluid 182 flow can flow internally through the block structure 220 (e.g., flow internally through the plurality of extensions 228). Therefore, the heat transfer device 280 does not include the plurality of tubes 240 discussed above.

[0063] The plurality of ports 282 extending through the interior of the plurality of extensions 228 may define one or more flow paths (e.g., serpentine flow paths). For example, each port 282 may be connected in series 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 device 280. Alternatively, the plurality of ports 282 may define a plurality of flow paths (e.g., a plurality of serpentine flow paths) configured to direct portions of the flow of heated fluid 182 through the heat transfer device 280. For example, the plurality of ports 282 may define a plurality of flow paths arranged vertically along the plurality of extensions 228. In such embodiments, each flow path may be fluidly coupled to a 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 a second header 206 configured to discharge the flow of heated fluid 182 from the lubricant separation heat exchanger 118.

[0064] The block structure 220 of the heat transfer device 280 can be similarly positioned within the housing 202 of the lubricant separation heat exchanger 118 to separate the first cavity 232 from the second cavity 234 within the housing 202. In some embodiments, the heat transfer device 280 can include seals similar to those discussed above (e.g., base seal 238, additional seal 262) to separate the first cavity 232 from the second cavity 234 and prevent the mixture of lubricant and working fluid 180 from flowing directly from the first cavity 232 to the second cavity 234 (e.g., bypassing the plurality of channels 222). Additionally or alternatively, the base portion 230 of the block structure 220 can include a geometry (e.g., curvature) that corresponds to (e.g., matches) the geometry of the housing 202, as shown, to achieve a fluid seal between the block structure 220 and the housing 202.

[0065] In the illustrated embodiment, the block structure 220 also includes a plurality of passages 284 formed within the plurality of extensions 228. Specifically, each extension 228 may include one of the passages 284 formed therein, such as at the 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 the mixture 180 of lubricant and working fluid to flow between adjacent channels 222 defined by the plurality of extensions 228. Thus, the passages 284 are configured to direct the mixture 180 of lubricant and working fluid to flow through the heat transfer device 280 (e.g., from the first cavity 232 to the second cavity 234) via the plurality of channels 222. In some embodiments, the respective passages 284 of adjacent extensions 228 may be formed at opposite ends of the block structure 220 and / or the housing 202 (e.g., opposite longitudinal ends relative to the longitudinal axis 270). In this manner, the plurality of channels 222 and the plurality of passages 284 may cooperatively define a serpentine flow path configured to direct the lubricant and working fluid mixture 180 through the heat transfer device 280. As the lubricant and working fluid mixture 180 passes through the plurality of channels 222 and the plurality of passages 284, the mixture 180 may absorb heat from the heated fluid 182 flow directed through the plurality of ports 282 to cause the liquid working fluid within the mixture 180 to evaporate and generate evaporated working fluid 186 and separated lubricant 184, as similarly described above.

[0066] Fig.101 is a cross-sectional schematic top view of another embodiment of a lubricant separation heat exchanger 118 of a lubricant separation system 112 according to one aspect of the present disclosure. As similarly discussed above, the lubricant separation heat exchanger 118 is configured to receive a mixture 180 of lubricant and working fluid from the evaporator 110 and a heated stream of fluid 182 (e.g., from the lubricant reservoir 116), and place the mixture 180 in a heat transfer relationship with the heated stream of fluid 182 to enable separation of the mixture 180 into an evaporated working fluid 186 and a concentrated lubricant 184.

[0067] 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 housing 300 and a plurality of tubes 302 extending through the housing 300. The lubricant separation heat exchanger 118 further includes an inlet 304 configured to receive the mixture 180 of lubricant and working fluid from the evaporator 110 and direct the mixture 180 into the housing 300 (e.g., the interior volume of the housing 300). The lubricant separation heat exchanger 118 also includes an outlet 306 configured to discharge the separated lubricant 184 from the housing 300. As discussed in further detail below, the lubricant separation heat exchanger 118 may also include a plurality of baffles 308 disposed within the housing 300. The baffles 308 may define a desired flow path, such as a serpentine flow path 310, along which the mixture 180 of lubricant and working fluid may flow within the housing 300. In some embodiments, the plurality of tubes 302 may extend through one or more of the baffles 308, and the baffles 308 may also be configured to function as tube sheets to support the tubes 302 within the housing 300. The arrangement and configuration of the baffles 308 are described in further detail below.

[0068] The plurality of tubes 302 are configured to direct the flow of heated fluid 182 through the plurality of tubes and place the flow of heated fluid 182 in heat exchange relationship with the mixture 180 of lubricant and working fluid that may flow within the housing 300. In the illustrated embodiment, the plurality of tubes 302 are arranged to define a double pass configuration of the lubricant separation heat exchanger 118. That is, the flow of heated fluid 182 may flow twice (e.g., in opposite directions) along the length 311 of the housing 300. To this end, the plurality of tubes 302 may be separated into a first subset 312 of tubes and a second subset 316 of tubes, whereby the first subset 312 of tubes defines a first channel 314 of the lubricant separation heat exchanger 118, and the second subset 316 of tubes defines a second channel 318 of the lubricant separation heat exchanger 118.

[0069] The lubricant separation heat exchanger 118 includes additional features to enable sequential flow of the heated fluid 182 flow along the first channel 314 and the second channel 318. For example, the lubricant separation heat exchanger 118 includes a first manifold 320 (e.g., a first fluid tank) coupled to a first end 322 (e.g., a first longitudinal end) of the housing 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 each other (e.g., fluidly separated) via a partition 332 of the first manifold 320. In operation, the inlet 324 can receive a heated fluid 182 flow (e.g., from a heated fluid source, such as the lubricant reservoir 116) and direct the heated fluid 182 flow into the first cavity 328. The first cavity 328 is fluidly coupled to the first subset 312 of tubes. Thus, the heated flow of fluid 182 may be directed from the first cavity 328 into the first subset of tubes 312 to flow along the first passage 314 of the lubricant separation heat exchanger 118 .

[0070] The lubricant separation heat exchanger 118 further includes a second manifold 334 (e.g., a second fluid tank) coupled to a second end 336 (e.g., a second longitudinal end) of the housing 300. The second manifold 334 defines an additional cavity 338 that is configured to receive the heated fluid 182 flow from the first subset of tubes 312 and direct the heated fluid 182 flow into the second subset of tubes 316. Thus, the second manifold 334 is configured to direct the heated fluid 182 flow from the first channel 314 of the lubricant separation heat exchanger 118 to the second channel 318. The heated fluid 182 flow may flow through the second subset of tubes 316 and enter the second cavity 330 defined by the first manifold 320. From the second cavity 330, the heated fluid 182 flow 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 housing 300 and initially across the second passage 318, and is configured to exit the housing 300 after flowing across the first passage 314. Thus, the lubricant separation heat exchanger 118 may be configured in a counter-flow arrangement, as similarly described above.

[0071] As described above, the lubricant separation heat exchanger 118 can include baffles 308 disposed within the housing 300, and the baffles 308 can be configured to define a flow path of the lubricant and working fluid mixture 180 through the housing 300. For example, the baffles 308 can cooperatively define a serpentine flow path 310. To this end, in some embodiments, each baffle 308 can extend from the housing 300, completely across one of the channels 314, 318 and partially across the other of the channels 314, 318 (e.g., along the radial axis 340 of the lubricant separation heat exchanger 118). Thus, the baffles 308 can guide the lubricant and working fluid mixture 180 along the serpentine flow path 310 and completely across the first channel 314 and the second channel 318 in a repeating sequence along the serpentine flow path 310.

[0072] Additionally, in some embodiments, the baffles 308 can be arranged in the housing 300 with variable spacing relative to each other (e.g., longitudinal spacing, spacing along the length 311). That is, each baffle 308 can be spaced apart from one or more adjacent baffles 308 by a respective distance 342 (e.g., longitudinal distance, offset along the length 311) that extends along the length 311 (e.g., longitudinal axis) between adjacent baffles 308. For example, the distance 342 between adjacent baffles 308 can be determined based on the location of the baffles 308 within the housing 300, such as relative to the inlet 304 and / or outlet 306 of the housing 300. Specifically, the respective distance 342 between adjacent baffles 308 can increase as the associated adjacent baffles 308 are closer to the inlet 304, and / or can decrease as the associated adjacent baffles 308 are closer to the outlet 306.

[0073] The spacing or distance 342 between different adjacent baffles 308 can be selected to enable improved heat transfer from the heated fluid 182 flow to the lubricant and working fluid mixture 180. As the lubricant and working fluid mixture 180 is directed through the housing 300, heat is transferred from the heated fluid 182 flow within the plurality of tubes 302 to the lubricant and working fluid mixture 180. In this manner, the liquid working fluid within the lubricant and working fluid mixture 180 can be vaporized and separated from the lubricant within the lubricant and working fluid mixture 180. In effect, the vaporized working fluid 186 can rise within the housing 300, leaving the separated lubricant 184 at the base or bottom portion of the housing 300. Thus, as the lubricant and working fluid mixture 180 flows from the inlet 304 to the outlet 306, the volume of fluid (e.g., the lubricant and working fluid mixture 180) remaining at the base or bottom portion of the housing 300 can be reduced. The reduction in the volume of fluid at the bottom of the housing 300 can reduce the height of the fluid within the housing 300, which may otherwise result in portions of certain tubes 302 near the outlet 306 and / or second end 336 of the housing 300 not being submerged in liquid and thereby reducing the 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 housing 300. By reducing the distance 342 between adjacent baffles 308 positioned closer to the outlet 306 and / or second end 336 of the housing 300, the adjacent baffles 308 can be used to maintain a greater height of the fluid directed along the serpentine flow path 310 at or near the outlet 306 and / or second end 336 of the housing 300. In this manner, the variable distance 342 (e.g., variable longitudinal spacing) between adjacent baffles 308 can enable improved heat transfer from the heated fluid 182 to the mixture 180 across the entire length 311 of the housing 300.

[0074] Fig.11 1 is a cross-sectional schematic side view of an embodiment of a lubricant separation heat exchanger 118 of a lubricant separation system 112 according to one aspect of the present disclosure. The illustrated embodiment includes the same Fig.10 Similar elements and element numbers are shown as those described above. For example, the lubricant separation heat exchanger 118 includes a housing 300 with a plurality of tubes 302 extending therethrough. The lubricant separation heat exchanger 118 also includes a first manifold 320, a second manifold 334, and baffles 308 disposed within the housing 300 (e.g., with a variable spacing distance 342 therebetween). Thus, the illustrated lubricant separation heat exchanger 118 may be operated in a manner similar to that described above.

[0075] The illustrated embodiment also includes an inlet 304 of the housing 300 configured to receive the mixture 180 of lubricant and working fluid from the evaporator 110 and an outlet 306 of the housing 300 configured to discharge the separated lubricant 184 from the housing 300. The inlet 304 of the housing 300 can be configured to receive the mixture 180 of lubricant and working fluid from the overflow portion 192 of the evaporator 110, such as via gravity. In addition, the separated lubricant 184 can be directed from the lubricant separation heat exchanger 118 toward the ejector 130 and / or the lubricant reservoir 116.

[0076] 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 the working fluid from the housing 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 the mixture 180 of the lubricant and the working fluid to flow from the evaporator 110 into the housing 300 appropriately, desired, and / or effectively, and to enable the working fluid (e.g., separated from the lubricant) to flow out of the housing 300 appropriately, desired, and / or effectively and toward 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 housing 300 at a generally common axial position along the length 311 of the housing 300.

[0077] Fig.12 FIG. 1 is a schematic diagram of an embodiment of an evaporator 110 of a working fluid circuit 102 and a lubricant separation heat exchanger 118 of a lubricant separation system 112, which shows the fluid connection between the evaporator 110 and the lubricant separation heat exchanger 118. The lubricant separation heat exchanger 118 includes the same Fig.12 For example, the lubricant separation heat exchanger 118 includes a shell 300, a plurality of tubes 302, an inlet 304, an outlet 306, a baffle 308, a first working fluid outlet 360, and a second working fluid outlet 362. In addition, the evaporator 110 can be a hybrid falling film evaporator having a shell 188, in which a falling film portion 190 and an overflow portion 192 are provided, as similarly discussed above.

[0078] The inlet 304 of the housing 300 can be fluidly coupled to the overflow portion 192 of the evaporator 110 via an inlet conduit 400, and can be configured to receive the mixture 180 of lubricant and working fluid from the evaporator 110 via gravity. In some embodiments, the inlet conduit 400 can be fluidly coupled to the housing 188 of the evaporator 110 at a location away from the suction port of the evaporator 110. As described above, the first working fluid outlet 360 and the second working fluid outlet 362 can each be configured to direct the working fluid (e.g., the evaporated working fluid 186) from the lubricant separation heat exchanger 118 to the evaporator 110. For example, the lubricant separation system 112 can include a first outlet conduit 402 extending from the first working fluid outlet 360 (e.g., near the first end 322) to the evaporator 110. Specifically, the first outlet conduit 402 can be fluidly coupled to the housing 188 of the evaporator 110 at a first inlet location 404 positioned above the overflow portion 192 of the evaporator 110 (e.g., relative to the vertical axis 406, relative to directional gravity). As will be appreciated, the first working fluid outlet 360 and the first outlet conduit 402 can be configured to direct the evaporated working fluid 186 to flow back to the evaporator 110, where the evaporated working fluid was initially evaporated and separated from the mixture of lubricant and working fluid 180 (e.g., near the inlet 304) within the housing 300. In this manner, the pressure within the housing 300 of the lubricant separation heat exchanger 118 and within the housing 188 of the evaporator 110 can be more balanced and / or equalized, which can facilitate proper flow of the mixture of lubricant and working fluid 180 from the evaporator 110 into the lubricant separation heat exchanger 118.

[0079] The lubricant separation system 112 may also include a second outlet conduit 408 extending from the second working fluid outlet 362 (e.g., near the second end 366) to the evaporator 110. Specifically, 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 associated with the first outlet conduit 402 of the evaporator 110 (e.g., relative to the vertical axis 406, relative to the directional gravity). In some embodiments, the second inlet location 410 may be positioned near an outlet 412 (e.g., a partial outlet, a steam outlet) of the evaporator 110. As will be appreciated, the pressure near the second inlet location 410 within the shell 188 may be less than the pressure near the first inlet location 404 within the shell 188. The reduced pressure near the second inlet location 410 within the shell 188 can help the evaporated working fluid 186 flow 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 can further help the evaporated working fluid 186 flow out of the evaporator 110 via the outlet 412 .

[0080] Fig.13 is a schematic axial view of an embodiment of an evaporator 110 of the working fluid circuit 102 and a lubricant separation heat exchanger 118 of the lubricant separation system 112, the schematic axial view showing the 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.

[0081] The illustrated embodiments each illustrate an embodiment of the first manifold 320 discussed above. In particular, Fig.13 The embodiment of FIG. 3 shows a first manifold 320 having an inlet 324, an outlet 326, a first cavity 328, and a second cavity 330, wherein the first cavity 328 and the second cavity 330 are separated by a partition 332. Thus, Fig.13 The lubricant separation heat exchanger 118 is configured to receive a flow of heated fluid 182 from a single heated fluid source (eg, the lubricant reservoir 116 ).

[0082] Fig.14 The embodiment of FIG. 3 shows an embodiment of a 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. Thus, Fig.14The lubricant separation heat exchanger 118 is configured to direct the first heated fluid stream 436 and the second heated fluid stream 438 through the lubricant separation heat exchanger 118. Therefore, the lubricant separation heat exchanger 118 can transfer heat to the mixture 180 of lubricant and working fluid to fluids from different heat sources (e.g., the cooling system 150 and the lubricant reservoir 116). Therefore, the plurality of tubes 302 extending through the housing 300 can be associated with different fluids received from different heat sources. For example, the plurality of tubes 302 can be separated into a first group of tubes and a second group of tubes, wherein each group of tubes defines a respective first channel and a second channel through the housing 300. The first group of tubes can be configured to receive the first heated fluid stream 436 via a first inlet 420 and a first inlet cavity 422 and discharge the first heated fluid stream 436 via a first outlet 424 and a first outlet cavity 426. The first inlet cavity 422 and the first outlet cavity 426 can be separated by a first baffle 440. Similarly, the second set of tubes may be configured to receive a second heated fluid stream 438 via a second inlet 428 and a second inlet cavity 430 and to discharge the second heated fluid stream 438 via a second outlet 432 and a second outlet cavity 434. The second inlet cavity 430 and the second outlet cavity 434 may be separated by a second partition 442. Additionally, the first outlet cavity 426 and the second inlet cavity 430 may be separated by a third partition 444. In this manner, the lubricant separation heat exchanger 118 may achieve more versatile operation and separation of the working fluid from the lubricant.

[0083] Although only certain features and embodiments of the present disclosure are shown and described, many modifications and variations (e.g., size, dimensions, structure, shape and proportion of various elements, changes in parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, material use, color, orientation, etc.) may occur to those skilled in the art without materially departing from the novel teachings and advantages of the subject matter described in the claims. The order or sequence of any process or method steps may be changed or re-sequenced according to alternative embodiments. Therefore, it is to be noted that the appended claims are intended to cover all such modifications and variations that fall within the true spirit of the present disclosure.

[0084] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of an actual implementation (i.e., those features that are not relevant to the best mode currently contemplated for implementing the disclosure, or those features that are not relevant to implementing the claimed embodiments) may be described. It should be appreciated that in the development of such actual implementations, as in any engineering or design project, numerous implementation-specific decisions may be made. Such development work may be complex and time consuming, but these are routine tasks of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

[0085] The techniques presented and claimed herein refer to and apply to substantial objects and specific examples of a practical nature that improve the technical field of the invention in a demonstrable manner and are therefore not abstract, intangible, or purely theoretical. In addition, if any claim appended to the end of this specification contains one or more elements expressed as "means for [performing] [the function] ..." or "steps for [performing] [the function] ...", it is expected that such elements will be interpreted in accordance with 35 U.S.C. 112(f). However, for any claim containing elements specified in any other manner, it is intended that such elements will not be interpreted in accordance with 35 U.S.C. 112(f).

Claims

1. A heating, ventilation, air conditioning and refrigeration (HVAC&R) system comprising: an evaporator disposed along the working fluid circuit, wherein the evaporator is configured to transfer heat between the working fluid and a conditioning fluid; as well as A lubricant separation system, the lubricant separation system comprising a lubricant separation heat exchanger, the lubricant separation heat exchanger being configured to receive a mixture of the working fluid and the lubricant from the evaporator and to transfer heat from the heated fluid flow to the mixture to separate the working fluid from the lubricant, wherein the lubricant separation system is configured to direct the working fluid separated from the lubricant to the evaporator.

2. The HVAC&R system of claim 1, wherein the lubricant separation heat exchanger comprises a housing and a heat transfer device disposed within the housing, wherein the heat transfer device is configured to place the mixture and the heated fluid stream in a heat exchange relationship.

3. The HVAC&R system of claim 2, wherein the heat transfer device comprises a block structure, the block structure comprising a base portion and a plurality of extensions extending from the base portion, the plurality of extensions defining a plurality of channels, the plurality of channels defining a serpentine flow path, and the lubricant separation heat exchanger is configured to direct the mixture to flow along the serpentine flow path.

4. The HVAC&R system of claim 3, wherein the heat transfer device comprises a plurality of tubes extending within the serpentine flow path, and the plurality of tubes are configured to direct the heated fluid flow through the plurality of tubes to place the mixture and the heated fluid flow in the heat exchange relationship.

5. The HVAC&R system of claim 1 , wherein the lubricant separation heat exchanger comprises a housing and a plurality of tubes extending within the housing, the housing comprising an inlet configured to receive the mixture from the evaporator and an outlet configured to direct the working fluid separated from the lubricant to the evaporator.

6. The HVAC&R system of claim 5, comprising a plurality of baffles disposed within the housing, the plurality of baffles defining a serpentine flow path through the housing, and the lubricant separation heat exchanger is configured to direct the mixture to flow along the serpentine flow path.

7. The HVAC&R system of claim 6, wherein respective distances extending between adjacent ones of the plurality of baffles vary along a length of the housing.

8. The HVAC&R system of claim 7, wherein the respective distances decrease along the length of the housing from a first end of the housing proximate the inlet to a second end of the housing opposite the first end.

9. The HVAC&R system of claim 1 , wherein the evaporator comprises a hybrid falling film evaporator including a falling film portion and an overflow portion, the lubricant separation heat exchanger is configured to receive the mixture from the overflow portion, and the lubricant separation system is configured to direct the working fluid separated from the lubricant toward the falling film portion.

10. The HVAC&R system of claim 1, wherein the lubricant separation heat exchanger is fluidly coupled to a lubricant reservoir, the lubricant reservoir is configured to store the lubricant, and the lubricant separation heat exchanger is configured to receive a heated flow of the lubricant as the heated fluid flow.

11. The HVAC&R system of claim 10, wherein the lubricant separation system is configured to direct the lubricant separated from the working fluid from the lubricant separation heat exchanger and toward the lubricant reservoir.

12. The HVAC&R system of claim 11, wherein the lubricant separation system includes an ejector, the lubricant separation heat exchanger is configured to direct the lubricant separated from the working fluid to the ejector, and the ejector is configured to direct the lubricant separated from the working fluid to the lubricant reservoir.

13. The HVAC&R system of claim 12, wherein the ejector is configured to receive a pressurized flow of working fluid as a motive fluid, and the ejector is configured to direct the motive fluid through the ejector to generate a vacuum to draw the lubricant separated from the working fluid from the lubricant separation heat exchanger and into the ejector.

14. The HVAC&R system of claim 13, comprising a compressor system disposed along the working fluid circuit, wherein the ejector is fluidly coupled to the compressor system and configured to receive a pressurized fluid flow from the compressor system.

15. The HVAC&R system of claim 14, wherein the lubricant separation system is configured to direct the heated flow of the lubricant from the lubricant separation heat exchanger to the compressor system.

16. A heating, ventilation, air conditioning and refrigeration (HVAC&R) system comprising: an evaporator disposed along a working fluid circuit; as well as a lubricant separation heat exchanger configured to place a mixture of working fluid and lubricant received from the evaporator in heat exchange relationship with a heated fluid stream received from a heated fluid source to separate the mixture into evaporated working fluid and separated lubricant, wherein the lubricant separation heat exchanger comprises: a first inlet configured to receive the mixture from the evaporator; a second inlet configured to receive the heated fluid flow from the heated fluid source; a first outlet configured to direct the evaporated working fluid to the evaporator; and A second outlet is configured to discharge the separated lubricant from the lubricant separation heat exchanger.

17. The HVAC&R system of claim 16, comprising an ejector fluidly coupled to the second outlet, wherein the ejector is configured to receive the separated lubricant from the lubricant separation heat exchanger and direct the separated lubricant to a lubricant reservoir of the HVAC&R system.

18. The HVAC&R system of claim 16, wherein the lubricant separation heat exchanger comprises: case; a plurality of tubes extending within the housing and configured to direct the heated fluid flow through the plurality of tubes; and a plurality of baffles disposed within the housing, wherein the plurality of baffles define a serpentine flow path through the housing, and the lubricant separation heat exchanger is configured to direct the mixture along the serpentine flow path.

19. The HVAC&R system of claim 16, wherein the lubricant separation heat exchanger comprises: a block structure disposed within the housing, wherein the block structure defines a plurality of channels, and the plurality of channels cooperatively form a serpentine flow path configured to receive the mixture and direct the mixture through the serpentine flow path; as well as A plurality of tubes are disposed within the plurality of channels and extend along the serpentine flow path, wherein the plurality of tubes are configured to receive the heated fluid flow and direct it through the plurality of tubes.

20. A heating, ventilation, air conditioning and refrigeration (HVAC&R) system comprising: an evaporator disposed along a working fluid circuit; a compressor system disposed along the working fluid circuit and comprising a centrifugal compressor configured to direct a working fluid along the working fluid circuit, a lubricant reservoir configured to supply lubricant to the centrifugal compressor; as well as a lubricant separation system, the lubricant separation system comprising a lubricant separation heat exchanger configured to transfer heat from a heated lubricant flow received from the lubricant reservoir to a mixture of a working fluid and a lubricant received from the evaporator to separate the mixture into an evaporated working fluid and a separated lubricant, wherein 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 lubricant flow from the lubricant separation heat exchanger to the compressor system, and to direct the separated lubricant to the lubricant reservoir.

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