Compressor for HVAC&r system

Abstract

A compressor for a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system includes an impeller having a hub, a shroud, a first blade portion extending between the hub and the shroud, and a second blade portion extending external to the shroud along a direction of extension of the first blade portion from the hub to the shroud.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from and the benefit of U.S. Provisional Patent Application No. 63 / 476,505 , entitled “COMPRESSOR FOR HVAC&R SYSTEM,” filed Dec. 21, 2022, which is hereby 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 and / or claimed 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] Chiller systems, or 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 chiller system. The chiller system may 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 chiller system. For example, the chiller 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. In some embodiments, the conditioning fluid is cooled by an evaporator that absorbs heat from the conditioning fluid by evaporating working fluid. The working fluid is then compressed by a compressor and discharged to a condenser. In the condenser, the working fluid is cooled, typically by a water or air flow, and condensed into a liquid. An economizer may be utilized in the chiller system to improve performance. In systems that employ an economizer, the condensed working fluid may be directed to the economizer where the liquid working fluid at least partially evaporates. The resulting vapor may be extracted from the economizer and redirected to the compressor, while the remaining liquid working fluid from the economizer is directed to the evaporator.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 compressor for a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system includes an impeller having a hub, a shroud, a first blade portion extending between the hub and the shroud, and a second blade portion extending external to the shroud along a direction of extension of the first blade portion from the hub to the shroud.

[0006] In another embodiment, an impeller for a compressor of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a hub, a shroud, a first inlet configured to receive a first flow of working fluid, a second inlet configured to receive a second flow of working fluid, separate from the first flow of working fluid, and an impeller tip configured to discharge the first flow of working and the second flow of working fluid from the impeller.

[0007] In a further embodiment, a compressor for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes an impeller having a hub, a shroud, a first blade portion extending between the hub and the shroud, a first inlet configured to direct a first flow of working fluid from an evaporator of the HVAC&R system to the first blade portion, a second blade portion extending external to the shroud, and a second inlet configured to direct a second flow of working fluid from an economizer of the HVAC&R system to the second blade portion, wherein the impeller is configured to discharge the first flow of working fluid and the second flow of working fluid into a diffuser passage of the compressor.BRIEF DESCRIPTION OF THE 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 / or 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 a vapor compression system, in accordance with an aspect of the present disclosure;

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

[0013] FIG. 5 is a partial cross-sectional side view of an embodiment of a compressor configured to receive a fluid flow from an economizer, in accordance with an aspect of the present disclosure;

[0014] FIG. 6 is a partial cross-sectional side view of an embodiment of a compressor configured to receive a fluid flow from an economizer, in accordance with an aspect of the present disclosure;

[0015] FIG. 7 is a perspective view of an embodiment of an impeller that may be utilized in a compressor, in accordance with an aspect of the present disclosure;

[0016] FIG. 8 is a perspective view of an embodiment of an impeller that may be utilized in a compressor, in accordance with an aspect of the present disclosure;

[0017] FIG. 9 is a perspective view of an embodiment of an impeller that may be utilized in a compressor, in accordance with an aspect of the present disclosure;

[0018] FIG. 10 is a partial cross-sectional side view of an embodiment of a compressor configured to receive a fluid flow from an economizer, in accordance with an aspect of the present disclosure; and

[0019] FIG. 11 is a perspective view of an embodiment of an impeller that may be utilized in a compressor, in accordance with an aspect of the present disclosure.DETAILED DESCRIPTION

[0020] 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.

[0021] 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 noted 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.

[0022] As used herein, the terms “approximately,”“generally,” and “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 mean 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 mean 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. Further, it should be understood that mathematical terms, such as “planar,”“slope,”“perpendicular,”“parallel,” and so forth are intended to encompass features of surfaces or elements as understood to one of ordinary skill in the relevant art, and should not be rigidly interpreted as might be understood in the mathematical arts. For example, a “planar” surface is intended to encompass a surface that is machined, molded, or otherwise formed to be substantially flat or smooth (within related tolerances) using techniques and tools available to one of ordinary skill in the art. Similarly, a surface having a “slope” is intended to encompass a surface that is machined, molded, or otherwise formed to be oriented at an angle (e.g., incline) with respect to a point of reference using techniques and tools available to one of ordinary skill in the art.

[0023] Embodiments of the present disclosure relate to an HVAC&R system having a vapor compression system with a compressor and an economizer. Specifically, the vapor compression system includes a working fluid circuit (e.g., refrigerant circuit) having a compressor, a condenser, an evaporator, an expansion device, and an economizer. In operation, the compressor pressurizes a working fluid within the working fluid circuit and directs the working fluid to the condenser, which condenses the working fluid. The condensed working fluid is directed along the working fluid circuit to the economizer, which “flashes” the working fluid at a pressure that is between a pressure of the condenser and a pressure of the evaporator to produce a two-phase working fluid. From the economizer, vapor working fluid is directed to the compressor to be recompressed, and liquid working fluid is directed to the evaporator for evaporation via heat exchange with a conditioning fluid. The evaporator may then discharge the vaporized working fluid to the compressor to be recompressed.

[0024] The compressor (e.g., a single stage compressor, a centrifugal compressor) may be configured to compress the working fluid via rotation of an impeller and via a diffuser passage disposed downstream of the impeller relative to a flow of the working fluid through the compressor. During operation of the HVAC system, a first flow of working fluid may be directed into the compressor via a first inlet of the compressor (e.g., a suction inlet, from the evaporator). Operation of the impeller may provide a first portion (e.g., two-thirds) of a total working fluid pressure increase provided by the compressor to the first flow of working fluid received via the first inlet, and the diffuser passage may provide a second portion (e.g., a remaining one-third) of the total working fluid pressure increase provided by the compressor to the first flow of working fluid received via the first inlet. Furthermore, a second flow of working fluid from the economizer may be directed into the compressor via a second inlet of the compressor. The compressor may combine the second flow of working fluid received from the economizer and the first flow of working fluid received from the evaporator. It may be desirable to combine the two flows of working fluid within the compressor at approximately the same pressure to improve efficiency of the compressor. For example, combining two working fluid flows that are at different pressures may reduce the pressure of one of the working fluid flows, thereby reducing operational efficiency during pressurization of the combined working fluid flows.

[0025] Thus, present embodiments are directed to a compressor configured to combine working fluid flows (e.g., two vapor working fluid flows) at approximately the same pressure. For example, the compressor may include an impeller configured to separately receive the first flow of working fluid (e.g., vapor working fluid) and the second flow of working fluid (e.g., vapor working fluid) discussed above. The compressor may receive the first flow of working fluid from an evaporator of a working fluid circuit and receive the second flow of working fluid from an economizer of the working fluid circuit. The impeller may be configured to pressurize each of the first flow of working fluid and the second flow of working fluid toward a common target pressure. Additionally or alternatively, the impeller may be configured to enable mixing and / or combining of the first flow of working fluid at the second flow of working fluid at a location within the compressor (e.g., within the impeller) at which the first flow of working fluid and the second flow of working fluid have approximately the same pressure. For example, the impeller may include a first blade portion configured to pressurize the first flow of working fluid toward the common target pressure, and the impeller may include a second blade portion configured to pressurize the second flow of working fluid toward the common target pressure. The impeller may then combine the first and second flows of working fluid at approximately the same pressure. Thus, the impeller may enable more efficient operation of the compressor during pressurization of the two flows of working fluid that are separately received by the compressor.

[0026] Turning now to the drawings, FIG. 1 is a perspective view of an embodiment of a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system 10 utilized with a building 12 in 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.

[0027] 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 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.

[0028] Some examples of fluids that may be used as working fluids (e.g., refrigerants) 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.

[0029] 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.

[0030] 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.

[0031] The liquid working fluid delivered to the evaporator 38 may absorb heat from another cooling fluid or 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 cooling 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 cooling 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.

[0032] 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.

[0033] Additionally, the intermediate vessel 70 may provide for further expansion of the liquid working fluid due to 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 because of the 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.

[0034] 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.

[0035] Embodiments of the present disclosure are directed to a compressor (e.g., the compressor 32) having an impeller configured to receive a first flow of working fluid from an evaporator (e.g., the evaporator 38) disposed along a working fluid circuit and a second flow of working fluid from an economizer (e.g., the intermediate vessel 70) disposed along the working fluid circuit. The impeller may include respective blade portions (e.g., first blade portions and second blade portions) that pressurize each of the first flow of working fluid and the second flow of working fluid toward a common pressure. The impeller may then combine the first flow of working fluid pressurized by the first blade portions and the second flow of working fluid pressurized by the second blade portions with one another. The first and second flows of working fluid may be at approximately the same pressure during combination to enable improved efficiency of the compressor during operation.

[0036] With the foregoing in mind, FIG. 5 is a partial cross-sectional side view of an embodiment of the compressor 32, illustrating a working fluid flow path 100 of the compressor 32 configured to direct a flow of working fluid (e.g., vapor flow of working fluid) from an economizer 102 (e.g., intermediate vessel 70) into a main or primary working fluid flow path 104 of the compressor 32. The compressor 32 may be a single stage compressor. The compressor 32 includes a housing 106 (e.g., a compressor housing) in which an impeller 108 is disposed. The compressor 32 is configured to receive a first flow of working fluid 110 (e.g., a primary flow, a main flow) via a suction inlet 112 of the housing 106 and to direct the first flow of working fluid 110 toward the impeller 108. The suction inlet 112 may receive the first flow of working fluid 110 from an evaporator (e.g., evaporator 38) of an HVAC&R system (e.g., HVAC&R system 10) that includes the compressor 32. The impeller 108 may be driven into rotation by a motor (e.g., the motor 50) to impart mechanical energy to the first flow of working fluid 110. The first flow of working fluid 110 may exit the impeller 108 and be directed through a diffuser passage 114 (e.g., a pressure recovery portion) of the compressor 32 toward a volute 116 of the compressor 32. From the volute 116, the working fluid may be directed toward a condenser (e.g., the condenser 34) for heat exchange with a fluid, such as a cooling fluid, as described above.

[0037] The compressor 32 is also configured to receive a second flow of working fluid 118 (e.g., a secondary flow, a second flow) from the economizer 102 of the HVAC&R system 10 having the compressor 32. To this end, the compressor 32 includes an economizer inlet port 120 that may be fluidly coupled to the economizer 102. The economizer inlet port 120 is configured to direct the second flow of working fluid 118 into the housing 106 and along the working fluid flow path 100 formed therein. The working fluid flow path 100 is configured to direct the second flow of working fluid 118 into the impeller 108 to combine with the first flow of working fluid 110 (e.g., within the impeller 108). That is, the impeller 108 may be configured to receive the second flow of working fluid 118 and combine the second flow of working fluid 118 with the first flow of working fluid 110 upstream of the diffuser passage 114 of the compressor 32. For example, in the illustrated embodiment, the compressor 32 includes an eye seal support plate 122 (e.g., a first plate) coupled to a nozzle base plate 124 (e.g., a second plate) to cooperatively define an injection passage 126 (e.g., an annular passage) extending therebetween and about the impeller 108. For example, fasteners 128 (e.g., bolts) may couple the eye seal support plate 122 and the nozzle base plate 124 to one another, and an opening or space (e.g., annular space) may be formed between adjacent fasteners 128 to enable the second flow of working fluid 118 to flow from the economizer inlet port 120 into the injection passage 126. Further, mounts or bosses 130 of the eye seal support plate 122 through which the fasteners 128 may extend to couple the eye seal support plate 122 and the nozzle base plate 124 to one another may define the openings or spaces formed between the fasteners 128. The mounts 130 may have a geometric shape (e.g., an aerodynamic shape, profile, or configuration) to facilitate flow of the second flow of working fluid 118 into the injection passage 126, such as a shape that reduces a flow resistance of the second flow of working fluid 118. In additional or alternative embodiments, the injection passage 126 may be formed by or in other components of the compressor 32.

[0038] In certain embodiments, a cast vane or spacer 132 may be positioned between the eye seal support plate 122 and the nozzle base plate 124 to direct the second flow of working fluid 118 into the injection passage 126. For example, the cast vane 132 may be positioned adjacent to one of the fasteners 128, such as at an intake of the injection passage 126. The cast vane 132 may offset the eye seal support plate 122 and the nozzle base plate 124 from one another to form a suitably sized space that enables the second flow of working fluid 118 to enter the injection passage 126 at a desirable flow rate. The cast vane 132 may also adjust a flow direction of the second flow of working fluid 118 entering the injection passage 126. For instance, the cast vane 132 may transition (e.g., re-direct) the second flow of working fluid 118 into the injection passage 126 to flow with reduced obstruction that may otherwise be caused by impingement against the eye seal support plate 122 and / or against the nozzle base plate 124. Thus, the second flow of working fluid 118 may flow at a desirable rate and / or in a desirable direction through the injection passage 126.

[0039] As noted above, the impeller 108 and the diffuser passage 114 of the compressor 32 may each be configured to provide a portion of the pressurization or “lift” (e.g., a pressure rise from the suction inlet 112 to an exit or outlet of the diffuser passage 114) of the working fluid compressed by the compressor 32. For example, the impeller 108 may include first blade portions 134 (e.g., primary blades, first blade extensions) that extend within a first impeller passage 136 from an inlet 137 of the impeller 108 toward the diffuser passage 114. During rotation of the impeller 108, the first blade portions 134 may drive movement of the first flow of working fluid 110 through the first impeller passage 136. The first blade portions 134 may direct the first flow of working fluid 110 to flow through the impeller 108 and into the diffuser passage 114 via an impeller tip 138 (e.g., a discharge tip, a first radial tip, an impeller outlet). The first blade portions 134 may provide a first portion (e.g., approximately two-thirds) of a total pressurization or “lift” provided by the compressor 32 to the first flow of working fluid 110. As mentioned above, the diffuser passage 114 may provide a second portion (e.g., approximately one-third) of the pressurization or “lift” provided by the compressor 32 to the first flow of working fluid 110. Thus, at the impeller tip 138, the first flow of working fluid 110 may have a pressure associated with the first portion of lift or pressurization provided by the impeller 108 (e.g., approximately two-thirds of total lift provided by the compressor 32) to the first flow of working fluid 110.

[0040] During operation of the HVAC&R system 10 having the compressor 32, the pressure of the first flow of working fluid 110 at the impeller tip 138 may be greater than the pressure of the second flow of working fluid 118 received from the economizer 102 via the economizer inlet port 120. That is, the pressure of the first flow of working fluid 110 pressurized by the first blade portions 134 may be greater than desired for direct introduction of the second flow of working fluid 118 from the economizer 102 into the first flow of working fluid 110. Thus, the impeller 108 may include second blade portions 140 (e.g., secondary blades, second blade extensions) that, during rotation of the impeller 108, provide pressurization of the second flow of working fluid 118 toward the pressure of the first flow of working fluid 110. In some embodiments, the first blade portions 134 may pressurize the first flow of working fluid 110 and the second blade portions 140 may pressurize the second flow of working fluid 118, such that the first flow of working fluid 110 and the second flow of working fluid 118 are approximately the same pressure at the impeller tip 138. For example, the second blade portions 140 may extend within a second impeller passage 142 configured to receive the second flow of working fluid 118 from the injection passage 126. The second blade portions 140 may drive movement of the second flow of working fluid 118 through the second impeller passage 142 for discharge from the impeller 108 and into the diffuser passage 114 via the impeller tip 138. As such, the second blade portions 140 may cause the second flow of working fluid 118 to exit the impeller 108 from the second impeller passage 142 at approximately the same pressure as that of the first flow of working fluid 110 that exits the impeller 108 from the first impeller passage 136. The overall pressure ratio provided by the impeller 108 may therefore be increased to improve performance of the impeller 108.

[0041] In the illustrated embodiment, the first flow of working fluid 110 and the flow of second working fluid 118 may combine downstream of the impeller tip 138 in a direction of working fluid flow through the compressor 32 (e.g., from the impeller 108 to the diffuser passage 114). Because the pressure of the first flow of working fluid 110 and of the second flow of working fluid 118 may be approximately equal to one another at the impeller tip 138, the first flow of working fluid 110 and the second flow of working fluid 118 may be at substantially the same pressure during combination with one another. As a result, the operating pressure of the economizer 102 may be reduced (e.g., relative to the operating pressure of an economizer in which the impeller 108 does not pressurize the flow of working fluid received from the economizer), while enabling the second flow of working fluid 118 to be at a desirable pressure upon introduction into the main working fluid flow path 104 to mix with the first flow of working fluid 110. The HVAC&R system 10 may therefore operate more efficiently.

[0042] In the illustrated embodiment, the impeller 108 includes a first shroud 144 (e.g., lower shroud, inner shroud) that fluidly separates the first impeller passage 136 and the second impeller passage 142 from one another. For example, the first shroud 144 may extend from the inlet 137 to the impeller tip 138 and may block the first flow of working fluid 110 from flowing from the first impeller passage 136 to the second impeller passage 142. The first shroud 144 may similarly block the second flow of working fluid 118 from flowing from the second impeller passage 142 to the first impeller passage 136. As such, the first shroud 144 may block the first flow of working fluid 110 and the second flow of working fluid 118 from combining with one another upstream of the impeller tip 138. A first side or surface 143 (e.g., inner surface) of the first shroud 144 may be exposed to the first impeller passage 136 and thus the first flow of working fluid 110. A second side or surface 145 (e.g., an outer surface), opposite the first side 143, of the first shroud 144 may be exposed to the second impeller passage 142 and thus the second flow of working fluid 118.

[0043] Additionally, the impeller 108 may include a second shroud 146 (e.g., upper shroud, outer shroud) that at least partially defines or encloses the second impeller passage 142. The second shroud 146 may separate the second impeller passage 142 from the first impeller passage 136 it at least a portion of the impeller 108. The second shroud 146 may guide flow of the second flow of working fluid 118 from the injection passage 126 into the second impeller passage 142 to facilitate desirable flow of the second flow of working fluid 118 through the impeller 108, such as to force the second flow of working fluid 118 across the second blade portions 140 to enable pressurization of the second flow of working fluid 118. The second shroud 146 may also extend to the impeller tip 138 to facilitate flow of the second flow of working fluid 118 through the second impeller passage 142 and to the impeller tip 138. In some embodiments, the compressor 32 may also include a seal or guide (e.g., a labyrinth seal on the nozzle base plate 124) that extends adjacent to the injection passage 126 and the first shroud 144 to block flow of second flow of working fluid 118 between the second shroud 146 and the nozzle base plate 124 to facilitate flow of the second flow of working fluid 118 into the second impeller passage 142.

[0044] In some embodiments, one or more respective first blade portions 134 and one or more respective second blade portions 140 may be integral with one another. For example, one of the first blade portions 134 may be a first length of a common blade piece, and a corresponding one of the second blade portions 140 may be a second length of the common blade piece. The common blade piece may extend from the first impeller passage 136 and into the second impeller passage 142. Thus, the first blade portion 134 may be a portion of the common blade piece disposed within the first impeller passage 136, and the second blade 140 may be a portion of the common blade piece disposed within the second impeller passage 142. In such embodiments, the first shroud 144 may include a slot or opening configured to enable the common blade piece to extend therethrough to span across the first impeller passage 136 and the second impeller passage 142. In additional or alternative embodiments, the first blade portions 134 and the second blade portions 140 may be separate components. For example, the first blade portions 134 may extend within the first impeller passage 136 and terminate at the first shroud 144 (e.g., the first blade portions 134 may be coupled to a surface 148, such as a hub surface, of the impeller 108 and extend toward the first shroud 144, the first blade portions 134 may be coupled to the first side 143 of the first shroud 144 and extend toward the surface 148). The second blade portions 140 may extend within the second impeller passage 142 and terminate at the first shroud 144 (e.g., the second blade portions 140 may be coupled to the second side 145 of the first shroud 144 and extend away from the surface 148 and toward the second shroud 146 and / or the nozzle base plate 124 in an installed configuration of the impeller 108, the second blade portions 140 may be coupled to the second shroud 146 and extend toward the first shroud 144 and / or toward the surface 148).

[0045] FIG. 6 is a partial cross-sectional side view of an embodiment of the compressor 32 configured to enable combination (e.g., mixing) of the first flow of working fluid 110 and the second flow of working fluid 118 at a substantially common pressure, in accordance with the present techniques. In the illustrated embodiment, the first shroud 144 terminates upstream of the impeller tip 138 (e.g., relative to a flow of working fluid through the impeller 108). For example, the first shroud 144 may terminate at a shroud tip 166 where the second blade portions 140 initiate or originate within the impeller 108 (e.g., at an upstream tip of the second blade portions 140). The impeller 108 therefore includes a common impeller passage 170 (e.g., instead of the first impeller passage 136 separate from the second impeller passage 142) within which the first flow of working fluid 110 and the second flow of working fluid 118 may combine to form a combined flow 168. In this manner, the first flow of working fluid 110 and the second flow of working fluid 118 may combine within the impeller 108 and upstream of the impeller tip 138. The pressure of the first flow of working fluid 110 at a first blade end 172 (e.g., at a first inlet or upstream end of the common impeller passage 170), where the first flow of working fluid 110 may enter the common impeller passage 170, may be at approximately the same pressure as that of the second flow of working fluid 118 at a second blade end 174 (e.g., at a second inlet or upstream end of the common impeller passage 170), where the second flow of working fluid 118 may enter the common impeller passage 170. In some embodiments, the pressure at which the first flow of working fluid 110 and the second flow of working fluid 118 enter the common impeller passage 170 may be approximately fifty percent of a total lift provided by the compressor 32 to the first flow of working fluid 110. As the first flow of working fluid 110 and the second flow of working fluid 118 may have similar pressures when combined, the efficiency of the compressor 32 during operation to pressurize the working fluid may be improved.

[0046] Additionally, each of the first blade portions 134 and the second blade portions 140 may pressurize the combined flow 168 of the first flow of working fluid 110 and the second flow of working fluid 118. Extension of the second blade portions 140 from the first shroud 144 toward the second shroud 146 and / or toward the nozzle base plate 124 in the installed configuration of the impeller 108 may enable pressurization of working fluid (e.g., combined working fluid) throughout the common impeller passage 170. For instance, the second blade end 174 of the second shroud 146 may initiate pressurization of the second flow of working fluid 118 when the impeller 108 receives the second flow of working fluid 118. Thus, pressurization of the working fluid in the common impeller passage 170 may be more effective and / or efficient as compared to a configuration in which the second blade portions 140 are omitted or do not extend to the second shroud 146.

[0047] FIG. 7 is a perspective view of an embodiment of the impeller 108 including the first shroud 144, the second shroud 146, the first impeller passage 136, and the second impeller passage 142. The illustrated embodiment is similar to the embodiment described above with reference to FIG. 5. The first shroud 144 of the impeller 108 may form or define a first intake opening 200 (e.g., a main flow opening, a first inlet, the inlet 137) configured to receive the first flow of working fluid 110. Additionally, the first shroud 144 may extend to the impeller tip 138 (e.g., impeller outlet), as described above. The impeller tip 138 may be at least partially defined by a hub 204 of the impeller 108. In the illustrated embodiment, the impeller 108 also includes the second shroud 146 that extends in a direction of the second flow of working fluid 118 through the impeller 108 and that terminates at the impeller tip 138. As illustrated in a detailed view 202 of the impeller 108, the first shroud 144 may form the first impeller passage 136 between the hub 204 and the first shroud 144. The second shroud 146 may be offset from the first shroud 144 to form the second impeller passage 142 extending between the first shroud 144 and the second shroud 146.

[0048] The first blade portions 134 may be positioned within the first intake opening 200 (e.g., radially within the first shroud 144) and be configured to pressurize the first flow of working fluid 110 received by the impeller 108. The first blade portions 134 may extend from the first intake opening 200 to the impeller tip 138 (e.g., along the hub 204), in some embodiments. The first blade portions 134 may form first discharge openings 208 (e.g., main flow discharge openings) between adjacent first blade portions 134 within the first impeller passage 136. The impeller 108 may discharge pressurized first flow of working fluid 110 via the first discharge openings 208. Additionally, the second blade portions 140 may extend beyond the first shroud 144 (e.g., outward from the first shroud 144, external to the first shroud 144) along a direction of extension of the first blade portions 134 from the hub 204 to the first shroud 144 (e.g., in a direction opposite the first discharge openings 208 and / or the first blade portions 134, along a rotational axis of the impeller 108). The second shroud 146 may form second intake openings 210 (e.g., economizer flow intake openings, second inlets) configured to receive the second flow of working fluid 118, and the second blade portions 140 may form second discharge openings 212 (e.g., economizer flow discharge openings) between adjacent second blade portions 140 within the second impeller passage 142. The impeller 108 may discharge pressurized second flow of working fluid 118 via the second discharge openings 212.

[0049] As discussed herein, respective first blade portions 134 and second blade portions 140 may be integral with one another to form common blades or common blade pieces 206 (e.g., impeller blades, common blade portions, common blade segments). In such embodiments, the common blades 206 may extend through the first shroud 144, such as via openings 214 of the first shroud 144, and the second blade portions 140 of the common blade pieces 206 may extend from the first shroud 144 toward the second shroud 146. In some embodiments, the first blade portions 134 and the second blade portions 140 may be separate components. For example, the first blade portions 134 and the second blade portions 140 may be circumferentially offset from one another in an embodiment (e.g., the first blade portions 134 and the second blade portions 140 may not be coupled to or circumferentially aligned with one another). The first blade portions 134 and the second blade portions 140 may be oriented similarly with respect to the hub 204 and / or the first shroud 144 (e.g., at similar angles) to drive the first flow of working fluid 110 and the second flow of working fluid 118 to flow in an approximately common direction (e.g., toward the impeller tip 138). Thus, the first flow of working fluid 110 and the second flow of working fluid 118 may be discharged from the first discharge openings 208 and / or from the second discharge openings 212 in a common direction (e.g., angular direction, rotational direction) and may combine with one another more readily and / or with reduced flow resistance or turbulence (e.g., as compared to the first flow of working fluid 110 and the second flow of working fluid 118 flowing in disparate or crosswise directions).

[0050] FIG. 8 is a perspective view of an embodiment of the impeller 108 including the first shroud 144, the second shroud 146, and the common impeller passage 170. The illustrated embodiment is similar to the embodiment described above with reference to FIG. 6. In the illustrated embodiment, the first shroud 144 terminates upstream of the impeller tip 138, such as at an upstream end 240 of the second shroud 146. As illustrated in a detailed view 242 of FIG. 8, the common impeller passage 170 is formed between the hub 204 and the second shroud 146, and the shroud tip 166 of the first shroud 144 may terminate upstream of the common impeller passage 170 relative to a direction of the second flow of working fluid 118 through the impeller 108. Additionally, the second blade portions 140 may extend downstream of the shroud tip 166 of the first shroud 144 to the impeller tip 138 relative to a direction of the second flow of working fluid 118 through the impeller 108.

[0051] The first flow of working fluid 110 and second flow of working fluid 118 may combine in the common impeller passage 170. For example, the second intake openings 210 formed by the second shroud 146 may enable the second flow of working fluid 118 to flow through the second impeller passage 142 and into the common impeller passage 170 (e.g., common impeller outlet) to mix with the first flow of working fluid 110. Additionally, the first blade portions 134 and the second blade portions 140 (e.g., common blades pieces 206) may form discharge openings 244 (e.g., common discharge openings) between adjacent first blade portions 134 and / or between adjacent second blade portions 140 within the common impeller passage 170. The impeller 108 may discharge the combined flow of the first flow of working fluid 110 and the second flow of working fluid 118 via the discharge openings 244.

[0052] FIG. 9 is a perspective view of an embodiment of the impeller 108. In the illustrated embodiment, the impeller 108 includes the common impeller passage 170 in which the first flow of working fluid 110 and the second flow of working fluid 118 may combine. Additionally, the first blade portions 134 terminate upstream of the common impeller passage 170 and therefore upstream of the impeller tip 138. The impeller 108 may include one or more common blades 268 that extend downstream of the first blade portions 134, through the common impeller passage 170, and to the impeller tip 138 relative to a direction of the first flow of working fluid 110 through the impeller 108. In some embodiments, the first blade portions 134 and the common blades 268 may be blade portions that are separate (e.g., separately formed) from one another. In some embodiments, the first blade portions 134 and the common blades 268 may be arranged in an end-to-end configuration (e.g., one of the first blade portions 134 may abut a corresponding one of the common blades 268). Each common blade 268 may include one of the second blade portions 140 extending to the second shroud 146. One or more of the common blades 268 may include third blade portions 270 extending to the hub 204. That is, the second blade portions 140 and the third blade portions 270 may be integral with one another to form one or more of the common blades 268 extending within the common impeller passage 170. In additional or alternative embodiments, the second blade portions 140 and the third blade portions 270 may be separate components (e.g., separate components coupled to one another or circumferentially offset from one another).

[0053] A quantity of the first blade portions 134 may be different from a quantity of the second blade portions 140 and / or a quantity of the third blade portions 270 (e.g., a quantity of the common blades 268 within the common impeller passage 170). For example, a quantity of the second blade portions 140 and / or of the third blade portions 270 (e.g., a quantity of common blades 268) may be greater than a quantity of the first blade portions 134. As a result, the second blade portions 140 and / or the third blade portions 270 may provide greater pressurization of working fluid (e.g., the combination of the first flow of working fluid 110 and the second flow of working fluid 118) in the common impeller passage 170 as compared to a configuration in which the quantity of the second blade portions 140 and / or of the third blade portions 270 is approximately equal to the quantity of the first blade portions 134.

[0054] Similar techniques may also be applied to a configuration of the impeller 108 in which the impeller 108 includes the first impeller passage 136 and the second impeller passage 142 that are fluidly separate from one another (e.g., a configuration in which the common impeller passage 170 is omitted). For example, the first blade portions 134 may terminate upstream of the impeller tip 138, the second blade portions 140 may extend within the second impeller passage 142, and the third blade portions 270 may extend downstream of the first blade portions 134 within the first impeller passage 136. In such an embodiment, the quantity of the first blade portions 134 may be different from (e.g., fewer than) the quantity of the second blade portions 140 and / or of the third blade portions 270.

[0055] FIG. 10 is a partial cross-sectional side view of an embodiment of the compressor 32. In the illustrated embodiment, the first shroud 144 extends to the impeller tip 138, thereby at least partially forming both the first impeller passage 136 and the second impeller passage 142, which are fluidly separate from one another. Additionally, the compressor 32 may include a vane 300 (e.g., a stationary vane, a pre-rotation vane, a directing vane, a guide vane, one or more vanes) disposed upstream of the second impeller passage 142 (e.g., upstream of the second shroud 146) relative to a flow direction of the second flow of working fluid 118 along the working fluid flow path 100. While the illustrated embodiment shows one vane 300, it should be noted that the compressor 32 may include multiple vanes 300 (e.g., arrayed circumferentially about the impeller 108 and / or the first shroud 144).

[0056] The vane 300 may guide the second flow of working fluid 118 to flow toward the main working fluid flow path 104 in a more desirable manner to enable improved mixing of the second flow of working fluid 118 with the first flow of working fluid 110. For example, the vane 300 may guide (e.g., re-direct) the second flow of working fluid 118 to flow into the second impeller passage 142 in a more desirable direction (e.g., flow pattern, angular direction, circumferential direction) for combination (e.g., mixing) with the first flow of working fluid 110. For example, during operation of the compressor 32, the impeller 108, such as the second blade portions 140, may rotate relative to the vane 300. The vane 300 may guide flow of the second flow of working fluid 118 generally toward and / or in a direction of rotation of the impeller 108, such as in a tangential direction 302, and enable the second blade portions 140 to receive, engage with, and / or pressurize the second flow of working fluid 118 more readily (e.g., with reduced pressure losses, with reduced velocity losses, with reduce turbulence). As such, the vane 300 may enable more efficient flow of the second flow of working fluid 118 toward, into, and / or through the impeller 108.

[0057] The vane 300 may be coupled (e.g., fixedly coupled) to the nozzle base plate 124 to enable the impeller 108 to rotate relative to the vane 300. In some embodiments, the vane 300 may extend from the nozzle base plate 124 toward the first shroud 144 and may terminate prior to contact with the first shroud 144 to avoid interference with movement of the impeller 108 during the operation of the compressor 32. That is, the vane 300 may be external to the impeller 108 and may be offset from the first shroud 144 to form a space between the vane 300 and the first shroud 144 to mitigate contact between the vane 300 and the first shroud 144. The vane 300 may also be offset from the second shroud 146 (e.g., relative to a flow direction of the second flow of working fluid 118 toward the second impeller passage 142) to mitigate contact between the vane 300 and the second shroud 146, thereby avoiding interference with movement of the impeller 108 during the operation of the compressor 32. In some embodiments, the vane 300 may be integrally formed with the nozzle base plate 124. In additional or alternative embodiments, the vane 300 may be formed as a separate component from the nozzle base plate 124 and may therefore be secured to the nozzle base plate 124, such as with a fastener, a weld, an adhesive, or other suitable securement.

[0058] FIG. 11 is a perspective view of an embodiment of the impeller 108, illustrating the first shroud 144 extending to the impeller tip 138. During operation of the compressor 32, the impeller 108 may rotate in a rotational direction 330 (e.g., about a rotational axis of the impeller 108), thereby causing the second blade portions 140 to drive the second flow of working fluid 118 to flow toward the tangential direction 302 in the second impeller passage 142. That is, impingement of the second flow of working fluid 118 against the second blade portions 140 (e.g., within the second impeller passage 142) during rotation of the impeller 108 in the rotational direction 330 may drive flow of the second flow of working fluid 118 in the tangential direction 302. However, in some instances, the second flow of working fluid 118 may be directed toward and / or into the second impeller passage 142 (e.g., along the second side 145 of the first shroud 144) in a first flow direction 332 that is crosswise to the tangential direction 302.

[0059] Accordingly, the compressor 32 may include the vanes 300 described above, which may be secured to the nozzle base plate 124, in some embodiments. It should be appreciated that any of the embodiments of the impeller 108 described herein may be utilized with the vanes 300 (e.g., that are secured and / or fixed to the compressor 32). The vanes 300 may receive the second flow of working fluid 118 flowing in the first flow direction 332 and may direct the second flow of working fluid 118 into second impeller passage 142. As an example, the vanes 300 may adjust the flow of the second flow of working fluid 118 to more readily and efficiently flow into and / or through the second impeller passage 142 (e.g., in and / or toward the tangential direction 302). For instance, a surface 334 of each vane 300 may guide the second flow of working fluid 118 to flow in a second flow direction 336 to redirect the flow of the second flow of working fluid 118 toward a closer alignment with or to approach the tangential direction 302. Indeed, the second flow direction 336 of the second flow of working fluid 118 may be crosswise relative to a radius of the hub 204 and may more closely align with the tangential direction 302. As such, the second blade portions 140 may more readily receive and / or engage with the second flow of working fluid 118 and direct the second flow of working fluid 118 toward the tangential direction 302 (e.g., with reduced turbulence, pressure losses, and / or velocity losses) as compared to second flow of working fluid 118 traveling in a more disparate direction than the tangential direction 302 into the second impeller passage 142. In this way, the first flow of working fluid 110 and the second flow of working fluid 118 may combine and mix with more uniform and improved velocity distribution. As such, the vane 300 may enable more efficient (e.g., more uniform) flow and mixture of the second flow of working fluid 118 and the first flow of working fluid 110.

[0060] Although the illustrated vanes 300 have surfaces 334 with a curved geometry to guide the second flow of working fluid 118, additional or alternative vanes 300 may have surfaces 334 with any suitable geometry, such as a linear geometry, that may re-direct the second flow of working fluid 118 in the second flow direction 336. Furthermore, the compressor 32 may include any suitable number of the vanes 300, such as more vanes 300 than a number of the second blade portions 140, fewer vanes 300 than the number of the second blade portions 140, or the same quantity of vanes 300 as the second blade portions 140.

[0061] In some embodiments, the vanes 300 may also be implemented in a configuration of the impeller 108 having the common impeller passage 170. In such embodiments, the vanes 300 may guide the second flow of working fluid 118 to flow into the main working fluid flow path 104 and enable improved mixing of the second flow of working fluid 118 with the first flow of working fluid 110. For example, the vanes 300 may direct the second flow of working fluid 118 to enter the common impeller passage 170 in a flow direction (e.g., the second flow direction 336) that approaches or is more aligned with a flow direction of the first flow of working fluid 110 (e.g., driven by the first blade portions 134 of the impeller 108) within and discharged by the impeller 108. Thus, the vanes 300 may reduce undesirable characteristics of the combined second flow of working fluid 118 and the first flow of working fluid 110, such as a turbulence, pressure losses, velocity losses, and so forth, to enable more efficient flow of working fluid through the impeller 108.

[0062] As described in detail herein, present embodiments are directed to a compressor configured to combine working fluid flows (e.g., two vapor working fluid flows) at approximately the same pressure. For example, the compressor may include an impeller configured to separately receive a first flow of working fluid (e.g., vapor working fluid) and a second flow of working fluid (e.g., vapor working fluid). The compressor may receive the first flow of working fluid from an evaporator of a working fluid circuit and may receive the second flow of working fluid from an economizer of the working fluid circuit. The impeller may be configured to pressurize each of the first flow of working fluid and the second flow of working fluid toward a common target pressure. Additionally or alternatively, the impeller may be configured to enable mixing and / or combining of the first flow of working fluid at the second flow of working fluid at a location within the compressor (e.g., within the impeller) at which the first flow of working fluid and the second flow of working fluid have approximately the same pressure. For example, the impeller may include a first blade portion configured to pressurize the first flow of working fluid, and the impeller may include a second blade portion configured to pressurize the second flow of working fluid. The impeller may then combine the first and second flows of working fluid at approximately the same pressure. Thus, the impeller may enable more efficient operation of the compressor during pressurization of the two flows of working fluid that are separately received by the compressor. Indeed, the present techniques enable combination and mixing of two flows of working fluid that are separately received by the compressor with reduced turbulence, reduced pressure losses, and / or reduced velocity losses.

[0063] While only certain features and embodiments have been illustrated and described, many modifications and changes may occur to those skilled in the art, such as variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, such as temperatures and pressures, mounting arrangements, use of materials, colors, orientations, and so forth, 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 re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.

[0064] Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode, or those unrelated to enablement. 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.

[0065] 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).

Examples

Embodiment Construction

[0020]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.

[0021]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. ...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from and the benefit of U.S. Provisional Patent Application No. 63 / 476,505 , entitled “COMPRESSOR FOR HVAC&R SYSTEM,” filed Dec. 21, 2022, which is hereby 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 and / or claimed 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] Chiller systems, or 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 chiller system. The chiller system may 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 chiller system. For example, the chiller 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. In some embodiments, the conditioning fluid is cooled by an evaporator that absorbs heat from the conditioning fluid by evaporating working fluid. The working fluid is then compressed by a compressor and discharged to a condenser. In the condenser, the working fluid is cooled, typically by a water or air flow, and condensed into a liquid. An economizer may be utilized in the chiller system to improve performance. In systems that employ an economizer, the condensed working fluid may be directed to the economizer where the liquid working fluid at least partially evaporates. The resulting vapor may be extracted from the economizer and redirected to the compressor, while the remaining liquid working fluid from the economizer is directed to the evaporator.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 compressor for a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system includes an impeller having a hub, a shroud, a first blade portion extending between the hub and the shroud, and a second blade portion extending external to the shroud along a direction of extension of the first blade portion from the hub to the shroud.

[0006] In another embodiment, an impeller for a compressor of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a hub, a shroud, a first inlet configured to receive a first flow of working fluid, a second inlet configured to receive a second flow of working fluid, separate from the first flow of working fluid, and an impeller tip configured to discharge the first flow of working and the second flow of working fluid from the impeller.

[0007] In a further embodiment, a compressor for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes an impeller having a hub, a shroud, a first blade portion extending between the hub and the shroud, a first inlet configured to direct a first flow of working fluid from an evaporator of the HVAC&R system to the first blade portion, a second blade portion extending external to the shroud, and a second inlet configured to direct a second flow of working fluid from an economizer of the HVAC&R system to the second blade portion, wherein the impeller is configured to discharge the first flow of working fluid and the second flow of working fluid into a diffuser passage of the compressor.BRIEF DESCRIPTION OF THE 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 / or 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 a vapor compression system, in accordance with an aspect of the present disclosure;

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

[0013] FIG. 5 is a partial cross-sectional side view of an embodiment of a compressor configured to receive a fluid flow from an economizer, in accordance with an aspect of the present disclosure;

[0014] FIG. 6 is a partial cross-sectional side view of an embodiment of a compressor configured to receive a fluid flow from an economizer, in accordance with an aspect of the present disclosure;

[0015] FIG. 7 is a perspective view of an embodiment of an impeller that may be utilized in a compressor, in accordance with an aspect of the present disclosure;

[0016] FIG. 8 is a perspective view of an embodiment of an impeller that may be utilized in a compressor, in accordance with an aspect of the present disclosure;

[0017] FIG. 9 is a perspective view of an embodiment of an impeller that may be utilized in a compressor, in accordance with an aspect of the present disclosure;

[0018] FIG. 10 is a partial cross-sectional side view of an embodiment of a compressor configured to receive a fluid flow from an economizer, in accordance with an aspect of the present disclosure; and

[0019] FIG. 11 is a perspective view of an embodiment of an impeller that may be utilized in a compressor, in accordance with an aspect of the present disclosure.DETAILED DESCRIPTION

[0020] 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.

[0021] 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 noted 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.

[0022] As used herein, the terms “approximately,”“generally,” and “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 mean 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 mean 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. Further, it should be understood that mathematical terms, such as “planar,”“slope,”“perpendicular,”“parallel,” and so forth are intended to encompass features of surfaces or elements as understood to one of ordinary skill in the relevant art, and should not be rigidly interpreted as might be understood in the mathematical arts. For example, a “planar” surface is intended to encompass a surface that is machined, molded, or otherwise formed to be substantially flat or smooth (within related tolerances) using techniques and tools available to one of ordinary skill in the art. Similarly, a surface having a “slope” is intended to encompass a surface that is machined, molded, or otherwise formed to be oriented at an angle (e.g., incline) with respect to a point of reference using techniques and tools available to one of ordinary skill in the art.

[0023] Embodiments of the present disclosure relate to an HVAC&R system having a vapor compression system with a compressor and an economizer. Specifically, the vapor compression system includes a working fluid circuit (e.g., refrigerant circuit) having a compressor, a condenser, an evaporator, an expansion device, and an economizer. In operation, the compressor pressurizes a working fluid within the working fluid circuit and directs the working fluid to the condenser, which condenses the working fluid. The condensed working fluid is directed along the working fluid circuit to the economizer, which “flashes” the working fluid at a pressure that is between a pressure of the condenser and a pressure of the evaporator to produce a two-phase working fluid. From the economizer, vapor working fluid is directed to the compressor to be recompressed, and liquid working fluid is directed to the evaporator for evaporation via heat exchange with a conditioning fluid. The evaporator may then discharge the vaporized working fluid to the compressor to be recompressed.

[0024] The compressor (e.g., a single stage compressor, a centrifugal compressor) may be configured to compress the working fluid via rotation of an impeller and via a diffuser passage disposed downstream of the impeller relative to a flow of the working fluid through the compressor. During operation of the HVAC system, a first flow of working fluid may be directed into the compressor via a first inlet of the compressor (e.g., a suction inlet, from the evaporator). Operation of the impeller may provide a first portion (e.g., two-thirds) of a total working fluid pressure increase provided by the compressor to the first flow of working fluid received via the first inlet, and the diffuser passage may provide a second portion (e.g., a remaining one-third) of the total working fluid pressure increase provided by the compressor to the first flow of working fluid received via the first inlet. Furthermore, a second flow of working fluid from the economizer may be directed into the compressor via a second inlet of the compressor. The compressor may combine the second flow of working fluid received from the economizer and the first flow of working fluid received from the evaporator. It may be desirable to combine the two flows of working fluid within the compressor at approximately the same pressure to improve efficiency of the compressor. For example, combining two working fluid flows that are at different pressures may reduce the pressure of one of the working fluid flows, thereby reducing operational efficiency during pressurization of the combined working fluid flows.

[0025] Thus, present embodiments are directed to a compressor configured to combine working fluid flows (e.g., two vapor working fluid flows) at approximately the same pressure. For example, the compressor may include an impeller configured to separately receive the first flow of working fluid (e.g., vapor working fluid) and the second flow of working fluid (e.g., vapor working fluid) discussed above. The compressor may receive the first flow of working fluid from an evaporator of a working fluid circuit and receive the second flow of working fluid from an economizer of the working fluid circuit. The impeller may be configured to pressurize each of the first flow of working fluid and the second flow of working fluid toward a common target pressure. Additionally or alternatively, the impeller may be configured to enable mixing and / or combining of the first flow of working fluid at the second flow of working fluid at a location within the compressor (e.g., within the impeller) at which the first flow of working fluid and the second flow of working fluid have approximately the same pressure. For example, the impeller may include a first blade portion configured to pressurize the first flow of working fluid toward the common target pressure, and the impeller may include a second blade portion configured to pressurize the second flow of working fluid toward the common target pressure. The impeller may then combine the first and second flows of working fluid at approximately the same pressure. Thus, the impeller may enable more efficient operation of the compressor during pressurization of the two flows of working fluid that are separately received by the compressor.

[0026] Turning now to the drawings, FIG. 1 is a perspective view of an embodiment of a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system 10 utilized with a building 12 in 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.

[0027] 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 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.

[0028] Some examples of fluids that may be used as working fluids (e.g., refrigerants) 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.

[0029] 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.

[0030] 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.

[0031] The liquid working fluid delivered to the evaporator 38 may absorb heat from another cooling fluid or 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 cooling 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 cooling 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.

[0032] 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.

[0033] Additionally, the intermediate vessel 70 may provide for further expansion of the liquid working fluid due to 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 because of the 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.

[0034] 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.

[0035] Embodiments of the present disclosure are directed to a compressor (e.g., the compressor 32) having an impeller configured to receive a first flow of working fluid from an evaporator (e.g., the evaporator 38) disposed along a working fluid circuit and a second flow of working fluid from an economizer (e.g., the intermediate vessel 70) disposed along the working fluid circuit. The impeller may include respective blade portions (e.g., first blade portions and second blade portions) that pressurize each of the first flow of working fluid and the second flow of working fluid toward a common pressure. The impeller may then combine the first flow of working fluid pressurized by the first blade portions and the second flow of working fluid pressurized by the second blade portions with one another. The first and second flows of working fluid may be at approximately the same pressure during combination to enable improved efficiency of the compressor during operation.

[0036] With the foregoing in mind, FIG. 5 is a partial cross-sectional side view of an embodiment of the compressor 32, illustrating a working fluid flow path 100 of the compressor 32 configured to direct a flow of working fluid (e.g., vapor flow of working fluid) from an economizer 102 (e.g., intermediate vessel 70) into a main or primary working fluid flow path 104 of the compressor 32. The compressor 32 may be a single stage compressor. The compressor 32 includes a housing 106 (e.g., a compressor housing) in which an impeller 108 is disposed. The compressor 32 is configured to receive a first flow of working fluid 110 (e.g., a primary flow, a main flow) via a suction inlet 112 of the housing 106 and to direct the first flow of working fluid 110 toward the impeller 108. The suction inlet 112 may receive the first flow of working fluid 110 from an evaporator (e.g., evaporator 38) of an HVAC&R system (e.g., HVAC&R system 10) that includes the compressor 32. The impeller 108 may be driven into rotation by a motor (e.g., the motor 50) to impart mechanical energy to the first flow of working fluid 110. The first flow of working fluid 110 may exit the impeller 108 and be directed through a diffuser passage 114 (e.g., a pressure recovery portion) of the compressor 32 toward a volute 116 of the compressor 32. From the volute 116, the working fluid may be directed toward a condenser (e.g., the condenser 34) for heat exchange with a fluid, such as a cooling fluid, as described above.

[0037] The compressor 32 is also configured to receive a second flow of working fluid 118 (e.g., a secondary flow, a second flow) from the economizer 102 of the HVAC&R system 10 having the compressor 32. To this end, the compressor 32 includes an economizer inlet port 120 that may be fluidly coupled to the economizer 102. The economizer inlet port 120 is configured to direct the second flow of working fluid 118 into the housing 106 and along the working fluid flow path 100 formed therein. The working fluid flow path 100 is configured to direct the second flow of working fluid 118 into the impeller 108 to combine with the first flow of working fluid 110 (e.g., within the impeller 108). That is, the impeller 108 may be configured to receive the second flow of working fluid 118 and combine the second flow of working fluid 118 with the first flow of working fluid 110 upstream of the diffuser passage 114 of the compressor 32. For example, in the illustrated embodiment, the compressor 32 includes an eye seal support plate 122 (e.g., a first plate) coupled to a nozzle base plate 124 (e.g., a second plate) to cooperatively define an injection passage 126 (e.g., an annular passage) extending therebetween and about the impeller 108. For example, fasteners 128 (e.g., bolts) may couple the eye seal support plate 122 and the nozzle base plate 124 to one another, and an opening or space (e.g., annular space) may be formed between adjacent fasteners 128 to enable the second flow of working fluid 118 to flow from the economizer inlet port 120 into the injection passage 126. Further, mounts or bosses 130 of the eye seal support plate 122 through which the fasteners 128 may extend to couple the eye seal support plate 122 and the nozzle base plate 124 to one another may define the openings or spaces formed between the fasteners 128. The mounts 130 may have a geometric shape (e.g., an aerodynamic shape, profile, or configuration) to facilitate flow of the second flow of working fluid 118 into the injection passage 126, such as a shape that reduces a flow resistance of the second flow of working fluid 118. In additional or alternative embodiments, the injection passage 126 may be formed by or in other components of the compressor 32.

[0038] In certain embodiments, a cast vane or spacer 132 may be positioned between the eye seal support plate 122 and the nozzle base plate 124 to direct the second flow of working fluid 118 into the injection passage 126. For example, the cast vane 132 may be positioned adjacent to one of the fasteners 128, such as at an intake of the injection passage 126. The cast vane 132 may offset the eye seal support plate 122 and the nozzle base plate 124 from one another to form a suitably sized space that enables the second flow of working fluid 118 to enter the injection passage 126 at a desirable flow rate. The cast vane 132 may also adjust a flow direction of the second flow of working fluid 118 entering the injection passage 126. For instance, the cast vane 132 may transition (e.g., re-direct) the second flow of working fluid 118 into the injection passage 126 to flow with reduced obstruction that may otherwise be caused by impingement against the eye seal support plate 122 and / or against the nozzle base plate 124. Thus, the second flow of working fluid 118 may flow at a desirable rate and / or in a desirable direction through the injection passage 126.

[0039] As noted above, the impeller 108 and the diffuser passage 114 of the compressor 32 may each be configured to provide a portion of the pressurization or “lift” (e.g., a pressure rise from the suction inlet 112 to an exit or outlet of the diffuser passage 114) of the working fluid compressed by the compressor 32. For example, the impeller 108 may include first blade portions 134 (e.g., primary blades, first blade extensions) that extend within a first impeller passage 136 from an inlet 137 of the impeller 108 toward the diffuser passage 114. During rotation of the impeller 108, the first blade portions 134 may drive movement of the first flow of working fluid 110 through the first impeller passage 136. The first blade portions 134 may direct the first flow of working fluid 110 to flow through the impeller 108 and into the diffuser passage 114 via an impeller tip 138 (e.g., a discharge tip, a first radial tip, an impeller outlet). The first blade portions 134 may provide a first portion (e.g., approximately two-thirds) of a total pressurization or “lift” provided by the compressor 32 to the first flow of working fluid 110. As mentioned above, the diffuser passage 114 may provide a second portion (e.g., approximately one-third) of the pressurization or “lift” provided by the compressor 32 to the first flow of working fluid 110. Thus, at the impeller tip 138, the first flow of working fluid 110 may have a pressure associated with the first portion of lift or pressurization provided by the impeller 108 (e.g., approximately two-thirds of total lift provided by the compressor 32) to the first flow of working fluid 110.

[0040] During operation of the HVAC&R system 10 having the compressor 32, the pressure of the first flow of working fluid 110 at the impeller tip 138 may be greater than the pressure of the second flow of working fluid 118 received from the economizer 102 via the economizer inlet port 120. That is, the pressure of the first flow of working fluid 110 pressurized by the first blade portions 134 may be greater than desired for direct introduction of the second flow of working fluid 118 from the economizer 102 into the first flow of working fluid 110. Thus, the impeller 108 may include second blade portions 140 (e.g., secondary blades, second blade extensions) that, during rotation of the impeller 108, provide pressurization of the second flow of working fluid 118 toward the pressure of the first flow of working fluid 110. In some embodiments, the first blade portions 134 may pressurize the first flow of working fluid 110 and the second blade portions 140 may pressurize the second flow of working fluid 118, such that the first flow of working fluid 110 and the second flow of working fluid 118 are approximately the same pressure at the impeller tip 138. For example, the second blade portions 140 may extend within a second impeller passage 142 configured to receive the second flow of working fluid 118 from the injection passage 126. The second blade portions 140 may drive movement of the second flow of working fluid 118 through the second impeller passage 142 for discharge from the impeller 108 and into the diffuser passage 114 via the impeller tip 138. As such, the second blade portions 140 may cause the second flow of working fluid 118 to exit the impeller 108 from the second impeller passage 142 at approximately the same pressure as that of the first flow of working fluid 110 that exits the impeller 108 from the first impeller passage 136. The overall pressure ratio provided by the impeller 108 may therefore be increased to improve performance of the impeller 108.

[0041] In the illustrated embodiment, the first flow of working fluid 110 and the flow of second working fluid 118 may combine downstream of the impeller tip 138 in a direction of working fluid flow through the compressor 32 (e.g., from the impeller 108 to the diffuser passage 114). Because the pressure of the first flow of working fluid 110 and of the second flow of working fluid 118 may be approximately equal to one another at the impeller tip 138, the first flow of working fluid 110 and the second flow of working fluid 118 may be at substantially the same pressure during combination with one another. As a result, the operating pressure of the economizer 102 may be reduced (e.g., relative to the operating pressure of an economizer in which the impeller 108 does not pressurize the flow of working fluid received from the economizer), while enabling the second flow of working fluid 118 to be at a desirable pressure upon introduction into the main working fluid flow path 104 to mix with the first flow of working fluid 110. The HVAC&R system 10 may therefore operate more efficiently.

[0042] In the illustrated embodiment, the impeller 108 includes a first shroud 144 (e.g., lower shroud, inner shroud) that fluidly separates the first impeller passage 136 and the second impeller passage 142 from one another. For example, the first shroud 144 may extend from the inlet 137 to the impeller tip 138 and may block the first flow of working fluid 110 from flowing from the first impeller passage 136 to the second impeller passage 142. The first shroud 144 may similarly block the second flow of working fluid 118 from flowing from the second impeller passage 142 to the first impeller passage 136. As such, the first shroud 144 may block the first flow of working fluid 110 and the second flow of working fluid 118 from combining with one another upstream of the impeller tip 138. A first side or surface 143 (e.g., inner surface) of the first shroud 144 may be exposed to the first impeller passage 136 and thus the first flow of working fluid 110. A second side or surface 145 (e.g., an outer surface), opposite the first side 143, of the first shroud 144 may be exposed to the second impeller passage 142 and thus the second flow of working fluid 118.

[0043] Additionally, the impeller 108 may include a second shroud 146 (e.g., upper shroud, outer shroud) that at least partially defines or encloses the second impeller passage 142. The second shroud 146 may separate the second impeller passage 142 from the first impeller passage 136 it at least a portion of the impeller 108. The second shroud 146 may guide flow of the second flow of working fluid 118 from the injection passage 126 into the second impeller passage 142 to facilitate desirable flow of the second flow of working fluid 118 through the impeller 108, such as to force the second flow of working fluid 118 across the second blade portions 140 to enable pressurization of the second flow of working fluid 118. The second shroud 146 may also extend to the impeller tip 138 to facilitate flow of the second flow of working fluid 118 through the second impeller passage 142 and to the impeller tip 138. In some embodiments, the compressor 32 may also include a seal or guide (e.g., a labyrinth seal on the nozzle base plate 124) that extends adjacent to the injection passage 126 and the first shroud 144 to block flow of second flow of working fluid 118 between the second shroud 146 and the nozzle base plate 124 to facilitate flow of the second flow of working fluid 118 into the second impeller passage 142.

[0044] In some embodiments, one or more respective first blade portions 134 and one or more respective second blade portions 140 may be integral with one another. For example, one of the first blade portions 134 may be a first length of a common blade piece, and a corresponding one of the second blade portions 140 may be a second length of the common blade piece. The common blade piece may extend from the first impeller passage 136 and into the second impeller passage 142. Thus, the first blade portion 134 may be a portion of the common blade piece disposed within the first impeller passage 136, and the second blade 140 may be a portion of the common blade piece disposed within the second impeller passage 142. In such embodiments, the first shroud 144 may include a slot or opening configured to enable the common blade piece to extend therethrough to span across the first impeller passage 136 and the second impeller passage 142. In additional or alternative embodiments, the first blade portions 134 and the second blade portions 140 may be separate components. For example, the first blade portions 134 may extend within the first impeller passage 136 and terminate at the first shroud 144 (e.g., the first blade portions 134 may be coupled to a surface 148, such as a hub surface, of the impeller 108 and extend toward the first shroud 144, the first blade portions 134 may be coupled to the first side 143 of the first shroud 144 and extend toward the surface 148). The second blade portions 140 may extend within the second impeller passage 142 and terminate at the first shroud 144 (e.g., the second blade portions 140 may be coupled to the second side 145 of the first shroud 144 and extend away from the surface 148 and toward the second shroud 146 and / or the nozzle base plate 124 in an installed configuration of the impeller 108, the second blade portions 140 may be coupled to the second shroud 146 and extend toward the first shroud 144 and / or toward the surface 148).

[0045] FIG. 6 is a partial cross-sectional side view of an embodiment of the compressor 32 configured to enable combination (e.g., mixing) of the first flow of working fluid 110 and the second flow of working fluid 118 at a substantially common pressure, in accordance with the present techniques. In the illustrated embodiment, the first shroud 144 terminates upstream of the impeller tip 138 (e.g., relative to a flow of working fluid through the impeller 108). For example, the first shroud 144 may terminate at a shroud tip 166 where the second blade portions 140 initiate or originate within the impeller 108 (e.g., at an upstream tip of the second blade portions 140). The impeller 108 therefore includes a common impeller passage 170 (e.g., instead of the first impeller passage 136 separate from the second impeller passage 142) within which the first flow of working fluid 110 and the second flow of working fluid 118 may combine to form a combined flow 168. In this manner, the first flow of working fluid 110 and the second flow of working fluid 118 may combine within the impeller 108 and upstream of the impeller tip 138. The pressure of the first flow of working fluid 110 at a first blade end 172 (e.g., at a first inlet or upstream end of the common impeller passage 170), where the first flow of working fluid 110 may enter the common impeller passage 170, may be at approximately the same pressure as that of the second flow of working fluid 118 at a second blade end 174 (e.g., at a second inlet or upstream end of the common impeller passage 170), where the second flow of working fluid 118 may enter the common impeller passage 170. In some embodiments, the pressure at which the first flow of working fluid 110 and the second flow of working fluid 118 enter the common impeller passage 170 may be approximately fifty percent of a total lift provided by the compressor 32 to the first flow of working fluid 110. As the first flow of working fluid 110 and the second flow of working fluid 118 may have similar pressures when combined, the efficiency of the compressor 32 during operation to pressurize the working fluid may be improved.

[0046] Additionally, each of the first blade portions 134 and the second blade portions 140 may pressurize the combined flow 168 of the first flow of working fluid 110 and the second flow of working fluid 118. Extension of the second blade portions 140 from the first shroud 144 toward the second shroud 146 and / or toward the nozzle base plate 124 in the installed configuration of the impeller 108 may enable pressurization of working fluid (e.g., combined working fluid) throughout the common impeller passage 170. For instance, the second blade end 174 of the second shroud 146 may initiate pressurization of the second flow of working fluid 118 when the impeller 108 receives the second flow of working fluid 118. Thus, pressurization of the working fluid in the common impeller passage 170 may be more effective and / or efficient as compared to a configuration in which the second blade portions 140 are omitted or do not extend to the second shroud 146.

[0047] FIG. 7 is a perspective view of an embodiment of the impeller 108 including the first shroud 144, the second shroud 146, the first impeller passage 136, and the second impeller passage 142. The illustrated embodiment is similar to the embodiment described above with reference to FIG. 5. The first shroud 144 of the impeller 108 may form or define a first intake opening 200 (e.g., a main flow opening, a first inlet, the inlet 137) configured to receive the first flow of working fluid 110. Additionally, the first shroud 144 may extend to the impeller tip 138 (e.g., impeller outlet), as described above. The impeller tip 138 may be at least partially defined by a hub 204 of the impeller 108. In the illustrated embodiment, the impeller 108 also includes the second shroud 146 that extends in a direction of the second flow of working fluid 118 through the impeller 108 and that terminates at the impeller tip 138. As illustrated in a detailed view 202 of the impeller 108, the first shroud 144 may form the first impeller passage 136 between the hub 204 and the first shroud 144. The second shroud 146 may be offset from the first shroud 144 to form the second impeller passage 142 extending between the first shroud 144 and the second shroud 146.

[0048] The first blade portions 134 may be positioned within the first intake opening 200 (e.g., radially within the first shroud 144) and be configured to pressurize the first flow of working fluid 110 received by the impeller 108. The first blade portions 134 may extend from the first intake opening 200 to the impeller tip 138 (e.g., along the hub 204), in some embodiments. The first blade portions 134 may form first discharge openings 208 (e.g., main flow discharge openings) between adjacent first blade portions 134 within the first impeller passage 136. The impeller 108 may discharge pressurized first flow of working fluid 110 via the first discharge openings 208. Additionally, the second blade portions 140 may extend beyond the first shroud 144 (e.g., outward from the first shroud 144, external to the first shroud 144) along a direction of extension of the first blade portions 134 from the hub 204 to the first shroud 144 (e.g., in a direction opposite the first discharge openings 208 and / or the first blade portions 134, along a rotational axis of the impeller 108). The second shroud 146 may form second intake openings 210 (e.g., economizer flow intake openings, second inlets) configured to receive the second flow of working fluid 118, and the second blade portions 140 may form second discharge openings 212 (e.g., economizer flow discharge openings) between adjacent second blade portions 140 within the second impeller passage 142. The impeller 108 may discharge pressurized second flow of working fluid 118 via the second discharge openings 212.

[0049] As discussed herein, respective first blade portions 134 and second blade portions 140 may be integral with one another to form common blades or common blade pieces 206 (e.g., impeller blades, common blade portions, common blade segments). In such embodiments, the common blades 206 may extend through the first shroud 144, such as via openings 214 of the first shroud 144, and the second blade portions 140 of the common blade pieces 206 may extend from the first shroud 144 toward the second shroud 146. In some embodiments, the first blade portions 134 and the second blade portions 140 may be separate components. For example, the first blade portions 134 and the second blade portions 140 may be circumferentially offset from one another in an embodiment (e.g., the first blade portions 134 and the second blade portions 140 may not be coupled to or circumferentially aligned with one another). The first blade portions 134 and the second blade portions 140 may be oriented similarly with respect to the hub 204 and / or the first shroud 144 (e.g., at similar angles) to drive the first flow of working fluid 110 and the second flow of working fluid 118 to flow in an approximately common direction (e.g., toward the impeller tip 138). Thus, the first flow of working fluid 110 and the second flow of working fluid 118 may be discharged from the first discharge openings 208 and / or from the second discharge openings 212 in a common direction (e.g., angular direction, rotational direction) and may combine with one another more readily and / or with reduced flow resistance or turbulence (e.g., as compared to the first flow of working fluid 110 and the second flow of working fluid 118 flowing in disparate or crosswise directions).

[0050] FIG. 8 is a perspective view of an embodiment of the impeller 108 including the first shroud 144, the second shroud 146, and the common impeller passage 170. The illustrated embodiment is similar to the embodiment described above with reference to FIG. 6. In the illustrated embodiment, the first shroud 144 terminates upstream of the impeller tip 138, such as at an upstream end 240 of the second shroud 146. As illustrated in a detailed view 242 of FIG. 8, the common impeller passage 170 is formed between the hub 204 and the second shroud 146, and the shroud tip 166 of the first shroud 144 may terminate upstream of the common impeller passage 170 relative to a direction of the second flow of working fluid 118 through the impeller 108. Additionally, the second blade portions 140 may extend downstream of the shroud tip 166 of the first shroud 144 to the impeller tip 138 relative to a direction of the second flow of working fluid 118 through the impeller 108.

[0051] The first flow of working fluid 110 and second flow of working fluid 118 may combine in the common impeller passage 170. For example, the second intake openings 210 formed by the second shroud 146 may enable the second flow of working fluid 118 to flow through the second impeller passage 142 and into the common impeller passage 170 (e.g., common impeller outlet) to mix with the first flow of working fluid 110. Additionally, the first blade portions 134 and the second blade portions 140 (e.g., common blades pieces 206) may form discharge openings 244 (e.g., common discharge openings) between adjacent first blade portions 134 and / or between adjacent second blade portions 140 within the common impeller passage 170. The impeller 108 may discharge the combined flow of the first flow of working fluid 110 and the second flow of working fluid 118 via the discharge openings 244.

[0052] FIG. 9 is a perspective view of an embodiment of the impeller 108. In the illustrated embodiment, the impeller 108 includes the common impeller passage 170 in which the first flow of working fluid 110 and the second flow of working fluid 118 may combine. Additionally, the first blade portions 134 terminate upstream of the common impeller passage 170 and therefore upstream of the impeller tip 138. The impeller 108 may include one or more common blades 268 that extend downstream of the first blade portions 134, through the common impeller passage 170, and to the impeller tip 138 relative to a direction of the first flow of working fluid 110 through the impeller 108. In some embodiments, the first blade portions 134 and the common blades 268 may be blade portions that are separate (e.g., separately formed) from one another. In some embodiments, the first blade portions 134 and the common blades 268 may be arranged in an end-to-end configuration (e.g., one of the first blade portions 134 may abut a corresponding one of the common blades 268). Each common blade 268 may include one of the second blade portions 140 extending to the second shroud 146. One or more of the common blades 268 may include third blade portions 270 extending to the hub 204. That is, the second blade portions 140 and the third blade portions 270 may be integral with one another to form one or more of the common blades 268 extending within the common impeller passage 170. In additional or alternative embodiments, the second blade portions 140 and the third blade portions 270 may be separate components (e.g., separate components coupled to one another or circumferentially offset from one another).

[0053] A quantity of the first blade portions 134 may be different from a quantity of the second blade portions 140 and / or a quantity of the third blade portions 270 (e.g., a quantity of the common blades 268 within the common impeller passage 170). For example, a quantity of the second blade portions 140 and / or of the third blade portions 270 (e.g., a quantity of common blades 268) may be greater than a quantity of the first blade portions 134. As a result, the second blade portions 140 and / or the third blade portions 270 may provide greater pressurization of working fluid (e.g., the combination of the first flow of working fluid 110 and the second flow of working fluid 118) in the common impeller passage 170 as compared to a configuration in which the quantity of the second blade portions 140 and / or of the third blade portions 270 is approximately equal to the quantity of the first blade portions 134.

[0054] Similar techniques may also be applied to a configuration of the impeller 108 in which the impeller 108 includes the first impeller passage 136 and the second impeller passage 142 that are fluidly separate from one another (e.g., a configuration in which the common impeller passage 170 is omitted). For example, the first blade portions 134 may terminate upstream of the impeller tip 138, the second blade portions 140 may extend within the second impeller passage 142, and the third blade portions 270 may extend downstream of the first blade portions 134 within the first impeller passage 136. In such an embodiment, the quantity of the first blade portions 134 may be different from (e.g., fewer than) the quantity of the second blade portions 140 and / or of the third blade portions 270.

[0055] FIG. 10 is a partial cross-sectional side view of an embodiment of the compressor 32. In the illustrated embodiment, the first shroud 144 extends to the impeller tip 138, thereby at least partially forming both the first impeller passage 136 and the second impeller passage 142, which are fluidly separate from one another. Additionally, the compressor 32 may include a vane 300 (e.g., a stationary vane, a pre-rotation vane, a directing vane, a guide vane, one or more vanes) disposed upstream of the second impeller passage 142 (e.g., upstream of the second shroud 146) relative to a flow direction of the second flow of working fluid 118 along the working fluid flow path 100. While the illustrated embodiment shows one vane 300, it should be noted that the compressor 32 may include multiple vanes 300 (e.g., arrayed circumferentially about the impeller 108 and / or the first shroud 144).

[0056] The vane 300 may guide the second flow of working fluid 118 to flow toward the main working fluid flow path 104 in a more desirable manner to enable improved mixing of the second flow of working fluid 118 with the first flow of working fluid 110. For example, the vane 300 may guide (e.g., re-direct) the second flow of working fluid 118 to flow into the second impeller passage 142 in a more desirable direction (e.g., flow pattern, angular direction, circumferential direction) for combination (e.g., mixing) with the first flow of working fluid 110. For example, during operation of the compressor 32, the impeller 108, such as the second blade portions 140, may rotate relative to the vane 300. The vane 300 may guide flow of the second flow of working fluid 118 generally toward and / or in a direction of rotation of the impeller 108, such as in a tangential direction 302, and enable the second blade portions 140 to receive, engage with, and / or pressurize the second flow of working fluid 118 more readily (e.g., with reduced pressure losses, with reduced velocity losses, with reduce turbulence). As such, the vane 300 may enable more efficient flow of the second flow of working fluid 118 toward, into, and / or through the impeller 108.

[0057] The vane 300 may be coupled (e.g., fixedly coupled) to the nozzle base plate 124 to enable the impeller 108 to rotate relative to the vane 300. In some embodiments, the vane 300 may extend from the nozzle base plate 124 toward the first shroud 144 and may terminate prior to contact with the first shroud 144 to avoid interference with movement of the impeller 108 during the operation of the compressor 32. That is, the vane 300 may be external to the impeller 108 and may be offset from the first shroud 144 to form a space between the vane 300 and the first shroud 144 to mitigate contact between the vane 300 and the first shroud 144. The vane 300 may also be offset from the second shroud 146 (e.g., relative to a flow direction of the second flow of working fluid 118 toward the second impeller passage 142) to mitigate contact between the vane 300 and the second shroud 146, thereby avoiding interference with movement of the impeller 108 during the operation of the compressor 32. In some embodiments, the vane 300 may be integrally formed with the nozzle base plate 124. In additional or alternative embodiments, the vane 300 may be formed as a separate component from the nozzle base plate 124 and may therefore be secured to the nozzle base plate 124, such as with a fastener, a weld, an adhesive, or other suitable securement.

[0058] FIG. 11 is a perspective view of an embodiment of the impeller 108, illustrating the first shroud 144 extending to the impeller tip 138. During operation of the compressor 32, the impeller 108 may rotate in a rotational direction 330 (e.g., about a rotational axis of the impeller 108), thereby causing the second blade portions 140 to drive the second flow of working fluid 118 to flow toward the tangential direction 302 in the second impeller passage 142. That is, impingement of the second flow of working fluid 118 against the second blade portions 140 (e.g., within the second impeller passage 142) during rotation of the impeller 108 in the rotational direction 330 may drive flow of the second flow of working fluid 118 in the tangential direction 302. However, in some instances, the second flow of working fluid 118 may be directed toward and / or into the second impeller passage 142 (e.g., along the second side 145 of the first shroud 144) in a first flow direction 332 that is crosswise to the tangential direction 302.

[0059] Accordingly, the compressor 32 may include the vanes 300 described above, which may be secured to the nozzle base plate 124, in some embodiments. It should be appreciated that any of the embodiments of the impeller 108 described herein may be utilized with the vanes 300 (e.g., that are secured and / or fixed to the compressor 32). The vanes 300 may receive the second flow of working fluid 118 flowing in the first flow direction 332 and may direct the second flow of working fluid 118 into second impeller passage 142. As an example, the vanes 300 may adjust the flow of the second flow of working fluid 118 to more readily and efficiently flow into and / or through the second impeller passage 142 (e.g., in and / or toward the tangential direction 302). For instance, a surface 334 of each vane 300 may guide the second flow of working fluid 118 to flow in a second flow direction 336 to redirect the flow of the second flow of working fluid 118 toward a closer alignment with or to approach the tangential direction 302. Indeed, the second flow direction 336 of the second flow of working fluid 118 may be crosswise relative to a radius of the hub 204 and may more closely align with the tangential direction 302. As such, the second blade portions 140 may more readily receive and / or engage with the second flow of working fluid 118 and direct the second flow of working fluid 118 toward the tangential direction 302 (e.g., with reduced turbulence, pressure losses, and / or velocity losses) as compared to second flow of working fluid 118 traveling in a more disparate direction than the tangential direction 302 into the second impeller passage 142. In this way, the first flow of working fluid 110 and the second flow of working fluid 118 may combine and mix with more uniform and improved velocity distribution. As such, the vane 300 may enable more efficient (e.g., more uniform) flow and mixture of the second flow of working fluid 118 and the first flow of working fluid 110.

[0060] Although the illustrated vanes 300 have surfaces 334 with a curved geometry to guide the second flow of working fluid 118, additional or alternative vanes 300 may have surfaces 334 with any suitable geometry, such as a linear geometry, that may re-direct the second flow of working fluid 118 in the second flow direction 336. Furthermore, the compressor 32 may include any suitable number of the vanes 300, such as more vanes 300 than a number of the second blade portions 140, fewer vanes 300 than the number of the second blade portions 140, or the same quantity of vanes 300 as the second blade portions 140.

[0061] In some embodiments, the vanes 300 may also be implemented in a configuration of the impeller 108 having the common impeller passage 170. In such embodiments, the vanes 300 may guide the second flow of working fluid 118 to flow into the main working fluid flow path 104 and enable improved mixing of the second flow of working fluid 118 with the first flow of working fluid 110. For example, the vanes 300 may direct the second flow of working fluid 118 to enter the common impeller passage 170 in a flow direction (e.g., the second flow direction 336) that approaches or is more aligned with a flow direction of the first flow of working fluid 110 (e.g., driven by the first blade portions 134 of the impeller 108) within and discharged by the impeller 108. Thus, the vanes 300 may reduce undesirable characteristics of the combined second flow of working fluid 118 and the first flow of working fluid 110, such as a turbulence, pressure losses, velocity losses, and so forth, to enable more efficient flow of working fluid through the impeller 108.

[0062] As described in detail herein, present embodiments are directed to a compressor configured to combine working fluid flows (e.g., two vapor working fluid flows) at approximately the same pressure. For example, the compressor may include an impeller configured to separately receive a first flow of working fluid (e.g., vapor working fluid) and a second flow of working fluid (e.g., vapor working fluid). The compressor may receive the first flow of working fluid from an evaporator of a working fluid circuit and may receive the second flow of working fluid from an economizer of the working fluid circuit. The impeller may be configured to pressurize each of the first flow of working fluid and the second flow of working fluid toward a common target pressure. Additionally or alternatively, the impeller may be configured to enable mixing and / or combining of the first flow of working fluid at the second flow of working fluid at a location within the compressor (e.g., within the impeller) at which the first flow of working fluid and the second flow of working fluid have approximately the same pressure. For example, the impeller may include a first blade portion configured to pressurize the first flow of working fluid, and the impeller may include a second blade portion configured to pressurize the second flow of working fluid. The impeller may then combine the first and second flows of working fluid at approximately the same pressure. Thus, the impeller may enable more efficient operation of the compressor during pressurization of the two flows of working fluid that are separately received by the compressor. Indeed, the present techniques enable combination and mixing of two flows of working fluid that are separately received by the compressor with reduced turbulence, reduced pressure losses, and / or reduced velocity losses.

[0063] While only certain features and embodiments have been illustrated and described, many modifications and changes may occur to those skilled in the art, such as variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, such as temperatures and pressures, mounting arrangements, use of materials, colors, orientations, and so forth, 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 re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.

[0064] Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode, or those unrelated to enablement. 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.

[0065] 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).

Examples

Embodiment Construction

[0020]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.

[0021]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. ...

Claims

1. A compressor for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising:an impeller, comprising:a hub;a shroud;a first blade portion extending between the hub and the shroud; anda second blade portion extending external to the shroud along a direction of extension of the first blade portion from the hub to the shroud.

2. The compressor of claim 1, wherein the compressor is configured to receive a first flow of working fluid and a second flow of working fluid, wherein the first blade portion is disposed within a first impeller passage of the impeller configured to receive the first flow of working fluid, and the second blade portion is disposed within a second impeller passage of the impeller configured to receive the second flow of working fluid.

3. The compressor of claim 2, wherein the shroud separates the first impeller passage and the second impeller passage from one another.

4. The compressor of claim 2, wherein the compressor is configured to receive the first flow of working fluid from an evaporator of the HVAC&R system, and the compressor is configured to receive the second flow of working fluid from an economizer of the HVAC&R system.

5. The compressor of claim 1, wherein the hub defines an impeller tip, and the shroud extends to the impeller tip.

6. The compressor of claim 1, wherein the first blade portion and the second blade portion are integrally formed with one another to form a common blade piece of the impeller.

7. The compressor of claim 1, comprising a vane positioned upstream of the second blade portion relative to a direction of a flow of working fluid through the impeller, wherein the vane is configured to guide the flow of working fluid toward the second blade portion, and impeller is configured to rotate relative to the vane during operation of the compressor.

8. The compressor of claim 1, comprising an additional shroud, wherein the second blade portion extends from the shroud to the additional shroud.

9. The compressor of claim 1, wherein the shroud terminates upstream of an impeller tip defined by the hub relative to a flow of working fluid through the impeller.

10. The compressor of claim 1, wherein the shroud forms an intake opening of the impeller, the impeller comprises a third blade portion disposed within the intake opening and extending along the hub, and the third blade portion terminates upstream of the first blade portion and the second blade portion relative to a direction of working fluid flow through the impeller.

11. The compressor of claim 10, comprising a first plurality of first blade portions comprising the first blade portion, a second plurality of second blade portions comprising the second blade portion, and a third plurality of third blade portions comprising the third blade portion, wherein a quantity of the third plurality of third blade portions is different from a quantity of the second plurality of second blade portions and different from a quantity of the first plurality of first blade portions.

12. An impeller for a compressor of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, wherein the impeller comprises:a hub;a shroud;a first inlet configured to receive a first flow of working fluid;a second inlet configured to receive a second flow of working fluid, separate from the first flow of working fluid; andan impeller tip configured to discharge the first flow of working and the second flow of working fluid from the impeller.

13. The impeller of claim 12, comprising:a first impeller passage extending from the first inlet to the impeller tip; anda second impeller passage extending from the second inlet to the impeller tip,wherein the shroud separates the first impeller passage and the second impeller passage from one another.

14. The impeller of claim 12, comprising a common impeller passage configured to receive the first flow of working fluid via the first inlet and to receive the second flow of working fluid via the second inlet, wherein the common impeller passage is configured to combine the first flow of working fluid and the second flow of working fluid upstream of the impeller tip and to discharge a combined flow of the first flow of working fluid and the second flow of working fluid from the impeller via the impeller tip.

15. The impeller of claim 12, comprising:a first plurality of first blade portions extending from the hub toward the shroud in a direction of extension; anda second plurality of second blade portions extending external to the shroud along the direction of extension.

16. The impeller of claim 15, wherein the shroud is a first shroud, and the impeller comprises a second shroud coupled to the second plurality of second blade portions, wherein the second shroud at least partially defines the second inlet.

17. The impeller of claim 15, wherein each second blade portion of the second plurality of second blade portions extends from a corresponding first blade portion of the first plurality of first blade portions in the direction of extension, each first blade portion of the first plurality of first blade portions extends to the impeller tip, and each second blade portion of the second plurality of second blade portions extends to the impeller tip.

18. A compressor for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising:an impeller, comprising:a hub;a shroud;a first blade portion extending between the hub and the shroud;a first inlet configured to direct a first flow of working fluid from an evaporator of the HVAC&R system to the first blade portion;a second blade portion extending external to the shroud; anda second inlet configured to direct a second flow of working fluid from an economizer of the HVAC&R system to the second blade portion,wherein the impeller is configured to discharge the first flow of working fluid and the second flow of working fluid into a diffuser passage of the compressor.

19. The compressor of claim 18, wherein the impeller comprises:a first impeller passage comprising the first blade portion;a second impeller passage comprising the second blade portion; andan impeller outlet,wherein the first impeller passage and the second impeller passage are separated by the shroud, and the shroud extends to the impeller outlet.

20. The compressor of claim 18, wherein the impeller comprises a common impeller passage, wherein the first blade portion and the second blade portion are disposed within the common impeller passage, the common impeller passage is configured to receive and combine the first flow of working fluid and the second flow of working fluid upstream of a tip of the impeller, and the impeller is configured to direct a combined flow of the first flow of working fluid and the second flow of working fluid into the diffuser passage via the tip of the impeller.

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