EP4680902A1

EP4680902A1 - Variable geometry regulation system of a compressor for a heating, ventilation, air conditioning, and/or refrigeration system

Info

Publication number: EP4680902A1
Application number: EP24775537.4A
Authority: EP
Inventors: Francois Charles Andre CLUNET; Damien Jean Daniel Arnou; Paul Eric LE SAUSSE; Florin Iancu
Original assignee: Tyco Fire and Security GmbH
Current assignee: Tyco Fire and Security GmbH
Priority date: 2023-03-20
Filing date: 2024-03-18
Publication date: 2026-01-21
Also published as: WO2024196884A1; TW202445067A; KR20250163376A; CN120936839A

Abstract

A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a vapor compression circuit and a compressor fluidly coupled to the vapor compression circuit. The compressor includes a first compressor stage with a first diffuser passage, a second compressor stage with a second diffuser passage, and a variable geometry diffuser (VGD) regulation system. The VGD regulation system includes a first VGD ring positioned within a first diffuser inlet of the first diffuser passage, wherein the first VGD ring includes a vane, a second VGD ring positioned within a second diffuser inlet of the second diffuser passage, and a VGD ring actuator coupled to the second VGD ring by at least one rod, wherein the at least one rod extends through the first VGD ring and the vane before coupling to the second VGD ring.

Description

VARIABLE GEOMETRY REGULATION SYSTEM OF A COMPRESSOR FOR A HEATING, VENTILATION, AIR CONDITIONING, AND/OR REFRIGERATION SYSTEM

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from and the benefit of U.S. Provisional Patent Application No. 63/453,211, entitled “VARIABLE GEOMETRY REGULATION SYSTEM OF A COMPRESSOR FOR A HEATING, VENTILATION, AIR CONDITIONING, AND/OR REFRIGERATION SYSTEM,” filed March 20, 2023, 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 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 cooling fluid (e.g., water) and may deliver the cooling fluid to conditioning equipment and/or a conditioned environment serviced by the chiller system. In such applications, the cooling fluid may be directed through downstream equipment, such as air handlers, to condition other fluids, such as air in a building. The chiller system may include a compressor configured to pressurize the working fluid and circulate the working fluid through a working fluid circuit. Unfortunately, the compressor may be susceptible to inefficient or undesirable operations. 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 an embodiment, a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes a vapor compression circuit and a compressor fluidly coupled to the vapor compression circuit. The compressor includes a first compressor stage with a first diffuser passage, a second compressor stage with a second diffuser passage, and a variable geometry diffuser (VGD) regulation system. The VGD regulation system includes a first VGD ring disposed within a first diffuser inlet of the first diffuser passage, wherein the first VGD ring includes a vane, a second VGD ring disposed within a second diffuser inlet of the second diffuser passage, and a VGD ring actuator coupled to the second VGD ring by at least one rod, wherein the at least one rod extends through the first VGD ring and the vane before coupling to the second VGD ring.

[0006] In an embodiment, a variable geometry diffuser (VGD) regulation system for a compressor of a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes a first VGD ring positioned adjacent to a first diffuser passage of the compressor, wherein the first VGD ring comprises a vane, a second VGD ring positioned at least partially within a second diffuser passage of the compressor, and a VGD ring assembly coupled to the first VGD ring and the second VGD ring, wherein the VGD ring assembly is coupled to the second VGD ring by at least one rod that extends through the first VGD ring and the vane before coupling to the second VGD ring.

[0007] In an embodiment, a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes a variable geometry diffuser (VGD) regulation system for a compressor of the HVAC&R system. The VGD regulation system includes a first VGD ring that includes a vane and is positioned adjacent to a first diffuser passage of the compressor, and a first VGD ring actuator assembly coupled to the first VGD ring and configured to actuate the first VGD ring to extend into or retract out of the first diffuser passage. The VGD regulation system includes a second VGD ring positioned at least partially within a second diffuser passage of the compressor and a second VGD ring actuator assembly coupled to the second VGD ring and configured to actuate the second VGD ring to extend into or retract out of the second diffuser passage, wherein the second VGD ring actuator assembly is coupled to the second VGD ring by at least one rod that extends through the first VGD ring and the vane before coupling to the second VGD ring. The HVAC&R system includes a control system communicatively coupled to the VGD regulation system, wherein the control system is configured to control actuation of the first VGD ring and the second VGD ring.

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 that may utilize 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 diagram of an embodiment of the vapor compression system of FIG. 2, in accordance with an aspect of the present disclosure;

[0012] FIG. 4 is a schematic diagram of an embodiment of the vapor compression system of FIG. 2, in accordance with an aspect of the present disclosure; [0013] FIG. 5 is a cross-sectional side view of an embodiment of a compact variable geometry diffuser (VGD) regulation system of a centrifugal compressor of the HVAC&R system, in accordance with an aspect of the present disclosure;

[0014] FIG. 6 is a perspective view of an embodiment of a compact VGD regulation system of a centrifugal compressor of the HVAC&R system, in accordance with an aspect of the present disclosure;

[0015] FIG. 7 is a cross-sectional side view of an embodiment of a compact VGD regulation system of a centrifugal compressor with the VGD rings in a retracted position, in accordance with an aspect of the present disclosure;

[0016] FIG. 8 is a cross-sectional side view of an embodiment of a compact VGD regulation system of a centrifugal compressor with a first VGD ring in an extended position and a second VGD ring in a retracted position, in accordance with an aspect of the present disclosure; and

[0017] FIG. 9 is a cross-sectional side view of an embodiment of a compact VGD regulation system of a centrifugal compressor with a first VGD ring in a retracted position and a second VGD ring in an extended position, in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

[0018] 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.

[0019] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0020] Embodiments of the present disclosure relate to a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system including a vapor compression system (e.g., vapor compression circuit) having a compressor, such as a centrifugal compressor including one or more stages (e.g., single stage, multistage, compact dual stage, compact triple stage). In operation, the compressor may pressurize a working fluid within the vapor compression system and direct the working fluid to a condenser, which may cool and condense the working fluid. The condensed working fluid may be directed to an expansion device, which may reduce a pressure of the working fluid, further cooling the working fluid. From the expansion device, the cooled working fluid may be directed to an evaporator, where the working fluid may be placed in a heat exchange relationship with a cooling fluid to cool the cooling fluid.

[0021] In some embodiments, the compressor may include an impeller configured to rotate to pressurize the working fluid and to direct the working fluid to a diffuser passage of the compressor. For example, the impeller may be coupled to a shaft, and the shaft may be configured to rotate relative to a housing of the compressor to drive rotation of the impeller relative to the housing. In some embodiments, the compressor may be a centrifugal compressor with one or more stages. For example, the compressor may be a multistage stage centrifugal compressor in which each stage includes a respective inlet (e.g., passage for the working fluid to enter a respective stage), an impeller, and a diffuser passage (e.g., passage for the working fluid to exit the respective stage). Furthermore, the multistage stage centrifugal compressor may include one or more regulation systems (e.g., head regulation systems, capacity regulation systems) to improve efficiency and performance of the compressor by reducing unstable and/or inconsistent work fluid flows within the compressor mitigating surges and/or stalls (e.g., diffuser stalls) during operation, while also reducing undesirable vibration and noise. Substantially high levels of vibration of the compressor may cause damage to the compressor and/or a system in which the compressor is implemented. The one or more regulation systems may affect a capacity of the compressor, and/or may affect a head of the compressor, or an amount of energy required to move unit mass of fluid from one point to another. Examples of the one or more regulation systems may be a pre-rotary vane regulation system, which may affect both the head and the capacity of the compressor, a variable geometry diffuser (VGD) regulation system, which may efficiently affect the capacity, a variable speed drive (VSD) regulation system, which may affect the head with high efficiency, a gas bypass regulation system, which is generally used for low capacity reduction and/or during transient operations such as startup of the compressor, and an injection flow regulation system. Specifically for multistage centrifugal compressors, including the VGD regulation system may lead to higher efficiency of the centrifugal compressors during operation by reducing undesirable noise and vibration and/or reducing instability or inconsistency of flow within the compressor to prevent surges and/or stalls.

[0022] In particular, the VGD regulation system may include a VGD actuator (e.g., VGD actuator assembly, VGD ring actuator assembly) coupled to a VGD component (e.g., VGD ring) that is controllably actuated (e.g., moved, translated, axially translated) by the VGD actuator to vary a size of a diffuser gap (e.g., space, passage, opening) within the diffuser passage by physically extending across and substantially blocking at least a portion of the diffuser passage. In this way, the VGD regulation system may controllably increase or decrease a flow rate of the working fluid through the diffuser passage and/or preventing back flow of the working fluid during low speed and/or low capacity operations. Specifically, for multistage centrifugal compressors, the VGD regulation system may include at least one respective VGD component for each diffuser passage per stage of the multistage compressor. However, due to the multiple stages of the multistage centrifugal compressors, maintaining stable rotor dynamics, or management of lateral and torsional vibrations, is critical to ensure proper operation and efficiency of the multistage centrifugal compressor, especially in multistage centrifugal compressors that include VSD. To achieve stability at higher revolutions per minute (RPM), and thus proper operation and efficiency of the multistage centrifugal compressor, it is desirable to reduce an overall length of the shaft of the centrifugal compressor to produce a more compact design (e.g., decrease a distance between one or more bearings of the compressor and the impeller of a first stage of the compressor). However, implementing the compact design limits space available for each stage of the multistage centrifugal compressors along the shaft, and thus may limit available space for the VGD regulation system design (e.g., installation of VGD components and/or one or more VGD actuators to actuate the VGD components).

[0023] Previous designs of implementing the VGD regulation system into multistage centrifugal compressors (e.g., VSD multistage centrifugal compressors) include utilizing a single VGD actuator to actuate each of the VGD components simultaneously. In some embodiments, each of the VGD components may actuate essentially a same fixed distance associated with a same actuator position. In such embodiments, each of the VGD components may have fixed and/or limited positional variability relative to one another. In some embodiments, even though each of the VGD components may be actuated to different respective positions relative to the diffuser gap associated with a same actuator position, and thus may adjust the respective diffuser gaps to varying sizes, utilizing a single VGD actuator may still produce a limited number of positional combinations of the VGD components (e.g., relative to one another). Therefore, it is now recognized that utilizing the single VGD actuator may be limiting and, at some operational levels (e.g., operational speeds, operational capacities), may yield unsuitable diffuser gap sizes and/or prove ineffective in reducing undesirable noise and vibration and/or reducing instability or inconsistency of flow within the compressor to prevent surges and/or stalls. [0024] Thus, it is now recognized that a VGD regulation system (e.g., VGD system) is desirable for multistage centrifugal compressors that includes independently operated (e.g., controlled) VGD components to improve efficiency and performance of the multistage centrifugal compressor, even at partial load conditions, by reducing instability or inconsistency of flow within the compressor and preventing surges and/or stalls, while also reducing undesirable noise and vibration. Accordingly, the present disclosure is directed to a compact VGD regulation system (e.g., compact VGD system) of a compact centrifugal compressor for a HVAC&R system. The compact VGD regulation system may efficiently regulate compressor capacity (e.g., multistage centrifugal compressor capacity) and include two or more VGD actuators each independently operating a respective VGD component associated with a respective diffuser passage of a stage of the multistage centrifugal compressor. In particular, the compact VGD regulation system enables two or more VGD actuators to each control a position of a respective VGD component of a respective stage of the multistage centrifugal compressor, while maintaining a desired length (e.g., compactness) of each stage, and thus maintaining a relatively compact (e.g., substantially short) overall shaft length (e.g., axial length). Furthermore, the two or more VGD actuators may be positioned (e.g., installed) in a plenum volume (e.g., space) of the multistage centrifugal compressor, which may be located in a space surrounding an initial impeller of a first compressor stage of the multistage centrifugal compressor. In this way, the two or more VGD actuators may be positioned in an area that optimizes a length of the compressor shaft and/or maintain a relatively short shaft length. The compact VGD regulation system may also include a system of rods (e.g., pins) extending from one or more VGD actuators to enable independent control of translation (e.g., movement, axial translation) of each respective VGD component, such as VGD components positioned at stages beyond a first stage of the multistage centrifugal compressor (e.g., second stage, third stage, etc.). In addition, one or more rods may be configured to pass through each diffuser passage by extending through (e.g., nested within, encased within) one or more fixed vanes of the multistage centrifugal compressor, and thus prevent any inefficiency and/or negative effects (e.g., via obstruction of the diffuser passage) on fluid flow that may be caused by the one or more rods passing through the diffuser passage.

[0025] Turning now to the drawings, FIG. l is a perspective view of an embodiment of an environment for a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system 10 in a building 12 for a typical commercial setting. The HVAC&R system 10 may include a vapor compression system 14 (e.g., a chiller, a heat pump) 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.

[0026] 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 refrigerant (e.g., working fluid) 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.

[0027] Some examples of fluids that may be used as refrigerants in the vapor compression system 14 are hydrofluorocarbon (HFC) based refrigerants, for example, R- 410A, R-407, R-134a, R-1233zd, R-1234ze, hydrofluoro olefin (HFO), "natural" refrigerants like ammonia (NH3), R-717, carbon dioxide (CO2), R-744, or hydrocarbonbased refrigerants, water vapor, or any other suitable refrigerant. In some embodiments, the vapor compression system 14 may be configured to efficiently utilize refrigerants having a normal boiling point of about 19 degrees Celsius (66 degrees Fahrenheit) at one atmosphere of pressure, also referred to as low pressure refrigerants, versus a medium pressure refrigerant, such as R-134a. As used herein, "normal boiling point" may refer to a boiling point temperature measured at one atmosphere of pressure.

[0028] 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.

[0029] The compressor 32 compresses a refrigerant vapor and delivers the vapor to the condenser 34 through a discharge passage. In some embodiments, the compressor 32 may be a centrifugal compressor including one or more compressor stages (e.g., compact dual stage compressor (CDS), multistage compressor, compact triple stage compressor (CTS)). The refrigerant 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 refrigerant vapor may condense to a refrigerant liquid in the condenser 34 as a result of thermal heat transfer with the cooling fluid. The liquid refrigerant 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.

[0030] The liquid refrigerant delivered to the evaporator 38 may absorb heat from another cooling fluid, which may or may not be the same cooling fluid used in the condenser 34. The liquid refrigerant in the evaporator 38 may undergo a phase change from the liquid refrigerant to a refrigerant 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 refrigerant. 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 refrigerant exits the evaporator 38 and returns to the compressor 32 by a suction line to complete the cycle.

[0031] 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 refrigerant 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.

[0032] Additionally, the intermediate vessel 70 may provide for further expansion of the liquid refrigerant because of a pressure drop experienced by the liquid refrigerant 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 (e.g., an interstage line) 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 refrigerant 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.

[0033] 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 incorporate embodiments of the HVAC&R system 10, the vapor compression system 14, the boiler 16, a chiller, a heat pump, and/or other HVAC&R equipment discussed above. 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 compact dual stage compressor 32. However, it should be noted that the systems described herein may be incorporated with other embodiments of the compressor 32, such as a single stage compressor, a compact triple stage compressor or a multistage compressor with any number of suitable compressor stages (e.g., four stages, five stages, six stages, eight stages, etc.).

[0034] As mentioned above, the present disclosure is directed to a compact VGD regulation system for regulating compressor capacity (e.g., multistage centrifugal compressor capacity) by including two or more actuators each independently operating a respective VGD component associated with a respective diffuser passage of a stage of the multistage centrifugal compressor (e.g., compressor 32). Each of the embodiments illustrated in the aforementioned figures includes a VGD regulation system in accordance with present embodiments. In particular, the compact VGD regulation system enables two or more actuators to each control a position of a respective VGD component of a respective stage of the multistage centrifugal compressor, while maintaining a desired length (e.g., compactness) of each stage, and thus maintaining a relatively compact (e.g., substantially short) overall shaft length. Furthermore, the two or more VGD actuators may be positioned (e.g., installed) in a plenum volume (e.g., space) of the multistage centrifugal compressor, which may be located in a space surrounding an initial impeller of a first compressor stage of the multistage centrifugal compressor. In this way, the two or more VGD actuators may be positioned in an area that optimizes a length of the compressor shaft and/or maintains a relatively short shaft length. The compact VGD regulation system may also have a system of nested rods extending from the two or more actuators to enable independent control of each respective VGD. The rods are nested in that they extend through passages, openings, channels, and the like that extend through compressor structure. In addition, one or more rods of the nested rods may be configured to pass through each diffuser passage via one or more fixed vanes of the multistage centrifugal compressor, and thus prevent any inefficiency and/or negative effects (e.g., via obstruction of the diffuser passage) on fluid flow that may be caused by the one or more rods passing through the diffuser passage.

[0035] With the foregoing in mind, FIG. 5 is a cross-sectional side view of an embodiment of the compressor 32 of the HVAC&R system 10 including a compact VGD regulation system 200. As discussed herein, the compressor 32 may be a compact dual stage (CDS) centrifugal compressor 32. The compressor 32 may include a housing 100 and a shaft 102 extending through the housing 100. The compressor 32 may also include one or more compressor stages 104 arranged consecutively along an axis 106 (e.g., a rotational axis of the shaft 102) of the compressor 32, with respect to a longitudinal axis 108. To facilitate discussion, the HVAC&R system 10 and its respective components may be described with reference to the longitudinal axis 108, a vertical axis 110, which is oriented relative to a direction of gravity, and a lateral axis 112. In the illustrated embodiment, the compressor includes a first compressor stage 114 adjacent a second compressor stage 116. Furthermore, each stage of the one or more compressor stages 104 may include a respective inlet, impeller, outlet, and a diffuser passage. For instance, the compressor 32 may include one or more impellers 118, such as a first impeller 120 positioned within the first compressor stage 114, and a second impeller 122 positioned within the second compressor stage 116. Each of the one or more impellers 118 may be coupled to the shaft 102, such as via one or more fasteners 124.

[0036] During operation of the compressor 32, the shaft 102 may rotate (e.g., via operation of the motor 50) and cause rotation of the first and second impellers 120, 122. Rotation of the first and/or second impellers 120, 122 may draw a working fluid (e.g., refrigerant) into the housing 100 via a suction inlet 128 (e.g., first inlet 128) and toward the first impeller 120, and drive the working fluid to flow along a working fluid flow path 126 (e.g., from the evaporator 38, from the intermediate vessel 70) through the compressor 32. The first impeller 120 may impart mechanical energy onto the working fluid and discharge the working fluid towards a first diffuser passage 130 of the first compressor stage 114 of the compressor 32 via a first impeller exit or outlet 132 of the first impeller 120. The working fluid may be directed through a first diffuser inlet 214 to the first diffuser passage 130, which is positioned downstream of the first diffuser inlet 214 relative to a working fluid flow through the first diffuser passage 130. Additionally, the working fluid may be directed from the first diffuser passage 130 to a second inlet chamber 134 of the second stage 116 of the compressor 32. In some embodiments, the second inlet chamber 134 may include one or more deswirl vanes 136 configured to guide the working fluid into an inlet 138 to the second impeller 122. In particular, an angle of the one or more deswirl vanes 136 may correspond to a rotational direction of the second impeller 122. The second impeller 122 may impart mechanical energy onto the working fluid and discharge the working fluid towards a second diffuser passage 140 of the second compressor stage 116 of the compressor 32 via a second impeller exit or outlet 142 of the second impeller 122. The working fluid may be directed through a second diffuser inlet 216 to the second diffuser passage 140, which is positioned downstream of the second diffuser inlet 216 relative to a working fluid flow through the first diffuser passage 140. Additionally, the working fluid may be directed from the second diffuser passage 140 to a volute 144 of the compressor 32 and from the volute 144 to a condenser (e.g., the condenser 34) for heat exchange with a fluid, such as a cooling fluid.

[0037] In some embodiments, during operation, a velocity of the working fluid entering the compressor 32 (e g., from the evaporator 38, from the intermediate vessel 70) and/or a velocity of the working fluid exiting the one or more impellers 120, 122 may vary, such as in low capacity and/or partial load conditions. For example, in some instances, the velocity of the working fluid may be relatively low (e.g., low capacity operation, low working fluid velocity operations, low compressor speed operations). In this instance, the first and/or second impellers 120, 122 may not impart sufficient energy to the working fluid to enable the working fluid to traverse a first length 146 (e.g., radial distance value) of the first diffuser passage 130 to reach the second inlet chamber and/or to traverse a second length 148 (e.g., radial distance value) of the second diffuser passage 140 to reach the volute 144. In either case, the compressor 32 may experience a stall and/or a surge due to a low volume and/or an inconsistent or unstable flow of the working fluid through the first and/or second diffuser passage 130, 140. Accordingly, as discussed herein the compressor 32 may include the compact VGD regulation system 200 configured to independently adjust a respective volume of one or more diffuser passage inlets to provide consistent and stable flow of the working fluid through the one or more diffuser passages. Thus, the compressor 32, including the compact VGD regulation system 200, may operate more efficiently and provide improved performance across a wider range of operational conditions (e.g., low capacity operation, low working fluid velocity operations, low compressor speed operations, partial load conditions), even in situations where the velocity and/or volume of the working fluid may vary and/or be relatively low. [0038] In the some embodiments, the compact VGD regulation system 200 may include one or more independently controlled VGD ring assemblies 202. Each VGD ring assembly 202 of the one or more VGD ring assemblies 202 may include a VGD ring 204, one or more VGD rods 206 (e.g., pin), and a VGD ring actuator assembly 208. In particular, each stage of the one or more compressor stages 104 of the compressor 32 may include a VGD ring 204 positioned at an inlet to a respective diffuser passage (e.g., the first and/or second diffuser passage 130, 140). As discussed herein, the VGD ring 204 may be configured to vary a size (e.g., volume) of an inlet of a diffuser passage (e.g., a diffuser gap, diffuser opening) by physically extending across and substantially blocking at least a portion of the inlet of the diffuser passage. For example, the VGD ring 204 may be configured to translate (e.g., axially translate) in a first direction 210, with respect to the longitudinal axis 108 (e.g., the axis 106) to cause the respective inlet of the diffuser passage to decrease in size (e.g., volume), and to translate in a second direction 212 (e.g., a direction generally opposite the first direction 204) with respect to the longitudinal axis 108, to cause the respective inlet of the diffuser passage to increase in size (e.g., volume). In other words, a range of translational positions of the VGD ring 204 may be from a first translational position (e.g., a retracted position) in which the VGD ring 204 is completely out of the diffuser inlet enabling a largest possible (with respect to range of system configurations) space (e.g., gap, volume) of the diffuser inlet, to a second translational position (e.g., an extended position) in which the VGD ring 204 occupies a portion of a volume of the diffuser inlet enabling a smallest possible (with respect to range of system configurations) space (e.g., gap, volume) of the diffuser inlet. In this way, an axial position of the VGD ring 204 may correlate with a size of a respective diffuser inlet of the diffuser passage. As discussed herein, during operation, the compact VGD regulation system 200 may controllably increase or decrease a flow rate (e.g., velocity) of the working fluid through the diffuser passage and/or prevent back flow of the working fluid during low speed and/or low capacity operations by adjusting the respective axial positions of the one or more VGD rings 204. It should be understood that the retracted position and the extended position of each VGD ring 204 of the one or more of the VGD rings 204 is described relative to the respective diffuser inlet in which the VGD ring 204 is disposed. In some embodiments, a VGD ring 204 in a retracted position may occupy a portion of a volume of the respective diffuser inlet enabling a smallest possible (with respect to range of system configurations) space (e.g., gap, volume) of the diffuser inlet, and the VGD ring 204 in an extended position may be completely out of the respective diffuser inlet enabling a largest possible (with respect to range of system configurations) space (e.g., gap, volume) of the diffuser inlet.

[0039] Furthermore, each VGD ring assembly 202 may include one or more respective VGD rods 206 each coupled to the VGD ring 204 and configured to translate in the first and/or second directions 204, 206 to cause the VGD ring 204 to axially translate in the first and/or second directions 204, 206. In particular, the VGD ring 204 may be coupled at a respective first end of each of the one or more respective VGD rods 206, and the one or more respective rods 206 may be positioned at equivalent angles about the VGD ring 204. For example, in some embodiments, the VGD ring 204 may include three VGD rods 206 positioned at 120 degree angles about the VGD ring 204. In another embodiment, the VGD ring 204 may include four VGD rods 206 positioned at 90 degree angles about the VGD ring 204. It should be appreciated that, in some embodiments, each VGD ring 204 assembly 202 may include any suitable number of VGD rods 206 at any suitable angular position relative to one another and/or about the VGD ring 204 to enable sufficient translational movement of the VGD ring 204 via translation of the VGD rods 206. Also, while certain directions are referenced and illustrated, present embodiments may actuate the VGD ring 204 in any appropriate direction to achieved desired functionality based on relative positioning of system components.

[0040] In addition, each VGD ring assembly 202 may include a respective VGD ring actuator assembly 208 coupled to the one or more VGD rods 206. Specifically, in some embodiments, the VGD ring actuator assembly 208 may be coupled at a second end, opposite the first end, of each of the one or more VGD rods 206. Furthermore, the VGD ring actuator assembly 208 may be configured to actuate (e.g., translate, move) the VGD ring 204 via the one or more VGD rods 206. In some embodiments, each VGD ring actuator assembly 208 may include at least one VGD actuator 230 coupled to a VGD actuator ring 232 that is configured to rotate, via the actuator 230, in a first rotational direction 218 and/or a second rotational direction 220 about the axis 106. In particular, due to a linkage assembly coupling the VGD actuator 230 to the VGD actuator ring 232, a rotational force applied by the VGD actuator 230 to the VGD actuator ring, via the linkage assembly, causes the VGD actuator ring 232 to rotate (e.g., in the first and/or second rotational directions 218, 220) and translate (e.g., in the first and/or second direction 210, 212) simultaneously. Specifically, in some embodiments, rotation of the VGD actuator ring 232 in the first rotational direction 218 may cause the VGD ring 204, via the one or more VGD rods 206, to translate in the first direction 210, while rotation of the VGD actuator ring 232, via the VGD actuator 230, in the second rotational direction 220 may cause the VGD ring 204 via the one or more VGD rods 206 to translate in the second direction 212. Alternatively, in some embodiments, the rotation of the VGD actuator ring 232 in the second rotational direction 220 may cause the VGD ring 204, via the one or more VGD rods 206, to translate in the first direction 210, while rotation of the VGD actuator ring 232, via the VGD actuator 230, in the first rotational direction 218 may cause the VGD ring 204 via the one or more VGD rods 206 to translate in the second direction 212. Furthermore, in some embodiments, the compressor 32 may include two or more VGD ring assemblies 202 with a first portion of the two or more VGD ring assemblies 202 including respective VGD rings 204 configured to translate in the first direction 210 when the corresponding VGD actuator rings 232 rotate in the first rotational direction 218 and to translate in the section direction 212 when the corresponding VGD actuator rings 232 rotate in the second rotational direction 220, and a second portion of the two or more VGD ring assemblies 202 including respective VGD rings 204 configured to translate in the second direction 212 when the corresponding VGD actuator rings 232 rotate in the first rotational direction 218 and to translate in the first direction 210 when the corresponding VGD actuator rings 232 rotate in the second rotational direction 220. The improved compact design of one or more VGD ring assemblies 202 of the compact VGD regulation system 200 is discussed in more detail below with respect to FIGS. 6-9. [0041] To controllably actuate the one or more VGD ring assemblies 202, the HVAC&R system 10 may include a control system 222 (e.g., a controller, an automation controller, an electronic controller, a programmable controller, a VGD controller, a cloudcomputing device, control circuitry) communicatively coupled to and configured to operate the one or more VGD actuators 208 to independently regulate the axial position of the one or more VGD rings 204 to control and/or adjust a flow rate (e.g., velocity) of the working fluid through the respective diffuser passage (e.g., the first and/or second diffuser passage 130, 140). In this way, the control system 222 may enable consistent and stable flow of the working fluid through the one or more diffuser passages to reduce a potential of surge and/or stall conditions and improve performance of the compressor 34 even at varying operational conditions (e.g., low capacity operation, low working fluid velocity operations, low compressor speed operations, partial load conditions).

[0042] The control system 222 may include a memory 224 and processing circuitry 226 (e.g., a microprocessor). The memory 224 may include volatile memory, such as randomaccess memory (RAM), and/or non-volatile memory, such as read-only memory (ROM), optical drives, hard disc drives, solid-state drives, or any other non-transitory computer- readable medium storing instructions that, when executed, control operation of the compressor 32. The processing circuitry 226 may be configured to execute such instructions. As an example, the processing circuitry 226 may include one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more general purpose processors, or any combination thereof.

[0043] The control system 222 may be configured to enable adjustment of a position (e.g., an axial position) of the one or more VGD rings 204 relative to the axis 106 and/or relative to the housing 100. By way of example, the control system 222 may be configured to instruct one or more VGD actuators 230 to cause rotation of the respective VGD actuator ring 232 and thus cause translation of the corresponding (e g., coupled) one or more rods 206 relative to the axis 106 to drive translation of the corresponding (e.g., coupled) one or more VGD rings 204 relative to the axis 106. In other words, a rotational force about the axis 106 of a rotational movement of the one or more VGD actuator rings 232 may be transformed to a translational force to the translate (e.g., adjust, move) the VGD rings 204 relative to the axis 106 (e.g., in the first direction 210 and/or the second direction 212).

[0044] The control system 222 may be configured to control rotational movement and/or adjustment of the one or more VGD ring actuators 232 and therefore control translational movement and a position of the VGD rings 204 within the respective diffuser inlet. In particular, the vapor compression system 14 may include one or more sensors 228 communicatively coupled to the control system 222, and the control system 222 may control a position of the VGD rings 204 based on feedback from one or more sensors 228. The one or more sensors 228 may be communicatively coupled to the control system 222 and configured to monitor one or more operational conditions associated with the vapor compression system 14 and transmit sensor data indicative of one or more operational conditions to the control system 222. The control system 222 may be configured to receive the data associated with the one or more operational conditions and determine a flow condition (e.g., stall condition, surge condition) associated with the compressor 32 based on the one or more operational conditions. In particular, the control system 222 may be configured to determine a flow condition based on one or more operational condition values being outside of a range of desired operational condition values. For example, when the control system 222 determines that an operational value, received via the one or more sensors 228, is below a threshold value (e.g., lower limit of the desired range of values) and/or determines that the operational condition value is above a threshold value (e.g., upper limit of the desired range of values), the control system 22 may be configured to determine a flow condition (e.g., stall condition, surge condition) of the compressor 32 based on the received operational value being outside of the desired range of operational values.

[0045] In some embodiments, the one or more sensors 228 may be configured to transmit an indication of a flow condition of the compressor 32 to the control system 222. For instance, the one or more sensors 228 may be configured to transmit the indication when a monitored value of an operational condition falls outside of a desired range of values. For example, when the one or more sensors 228 detects that an operational condition value is below a threshold value (e.g., lower limit of the desired range of values) and/or detect that an operational condition value is above a threshold value (e.g., upper limit of the desired range of values), the one or more sensors 228 may be configured to transmit the indication of a flow condition (e.g., stall condition, surge condition) of the compressor 32 to the control system 222. In either case, the control system 222 may be configured to transmit control signals to the one or more VGD actuators 230 to adjust a position of the one or more VGD rings based on the flow condition of the compressor 32 (e.g., based on the received data and/or indication).

[0046] In some embodiments, the one or more sensors 228 may be temperature sensors configured to detect a temperature associated with the HVAC&R system 10, such as a temperature of the working fluid at particular points within the vapor compression system 14 and/or the compressor 32. For example, the one or more sensors 228 may detect a compressor discharge temperature, an evaporator discharge temperature, an intermediate vessel discharge temperature, and/or a suction inlet temperature. Additionally or alternatively, the one or more sensors 228 may be pressure sensors configured to detect a pressure of the working fluid at particular points within the vapor compression system 14 and/or the compressor 32. For example, the one or more sensors 228 may detect a compressor discharge pressure, an evaporator discharge pressure, an intermediate vessel discharge pressure, and/or a suction inlet pressure.

[0047] With the foregoing in mind, FIG. 6 is a perspective view of an embodiments of the compact VGD regulation system 200 of the CDS centrifugal compressor 32 of the HVAC&R system 10. In particular, and as illustrated in FIGS. 5 and 6, the CDS centrifugal compressor 32 may include two compressor stages 104, the first compressor stage 114 fluidly coupled to the second compressor stage 116. The first compressor stage 1 14 includes the first impeller 120 fluidly coupled to and configured to receive a portion of the working fluid from the suction inlet 128. Furthermore, the first compressor stage 114 includes the first diffuser passage 130, the first diffuser passage 130 fluidly coupled to and configured to receive the portion of the working fluid from the first impeller 120 via the first diffuser inlet 214. In particular, the first diffuser passage 130 may include and be formed between a first wall 250 (e.g., barrier, plate) and a second wall 252. For simplicity and ease of illustration, some components of the CDS centrifugal compressor 32, such as the first wall 250, are not shown to better illustrate internal components. In addition, the portion of working fluid may travel in one or more radial directions 254, with respect to the axis 106, along the first diffuser passage 130 from the first diffuser inlet 214 and towards an outer edge 255 of the second wall 252. The portion of working fluid may flow over the outer edge 255 of the second wall 252 and enter the second compressor stage 116. The second compressor stage 116 may include the second inlet chamber 134 fluidly coupled to and configured to receive the portion of the working fluid from the first diffuser passage 130. As discussed herein, in some embodiments, the second inlet chamber 134 may include the one or more deswirl vanes 136 configured to guide the working fluid into an inlet 138 of the second impeller 122. In particular, an angle of the one or more deswirl vanes 136 may correspond to a rotational direction of the second impeller 122. Furthermore, the second compressor stage 116 may include the second impeller fluidly coupled to the second inlet chamber 134 and configured to receive the portion of the working fluid from the second inlet chamber 134. In addition, the second compressor stage 116 includes the second diffuser passage 140, the second diffuser passage 140 fluidly coupled to and configured to receive the portion of the working fluid from the second impeller 122 via the second diffuser inlet 216. In particular, the second diffuser passage 140 may include and be formed between a third wall 256 (e.g., barrier, plate) and a fourth wall 257 of the compressor 32. For clarity, the third wall 256 and the fourth wall 257 are not illustrated in FIG. 6. Moreover, the portion of working fluid may flow in the one or more radial directions 254, with respect to the axis 106, along the second diffuser passage 140 from the second diffuser inlet 2016 and towards the volute 144 of the compressor 32.

[0048] As illustrated in FIG. 6, each of the first and second compressor stages 114, 116 may include one or more components of a respective VGD ring assembly 202. In particular, the first compressor stage 114 may include one or more components of a first VGD ring assembly 258 that includes a first VGD ring 260 positioned at (e.g., adjacent to) the first diffuser inlet 214, a first set of one or more VGD rods 262 coupled to the first VGD ring 260, and a first VGD ring actuator assembly 264 coupled to the first set of one or more VGD rods 262 and configured to actuate the first VGD ring 260 in the first and the second directions 210, 212 via the first set of one or more VGD rods 262. The first VGD ring actuator assembly 264 may include one or more first links 266 (e.g., connectors), a first VGD actuator ring 268, one or more first VGD actuators 270. In particular, the first VGD actuator ring 268 may be coupled to the one or more first VGD actuators 270 by the one or more first links 266 via one or more first pins 272 (e.g., fasteners). The one or more first VGD actuators 270 may be configured to rotationally actuate (e.g., move) the one or more first links 266 about one or more respective first actuator axes 274 to cause rotational movement of the first VGD actuator ring 268 in the first rotational direction 218 and/or the second rotational direction 220. The first VGD actuator ring 268 may include a first outer portion 276 (e.g., outer ring portion) coupled to (e.g., moveably coupled to) a first inner portion 278 (e.g., inner ring portion) of the first VGD actuator ring 268. In particular, a diameter of the first outer portion 276 may be larger than a diameter of the first inner portion 278. The first outer portion 276 may be configured to slide (e.g., move) in the first rotational direction 218 and the second rotational direction 220 while the first inner portion 278 does not rotate either the first rotational direction 218 or the second rotational direction 220. Furthermore, the one or more first links 266 may be coupled to the first outer portion 276 and may cause the first outer portion 276 to simultaneously rotate in the first rotational direction 218 and translate in the first direction 210 or to simultaneously rotate in the second rotational direction 220 and translate in the second direction. In addition, the first outer portion 276 may be coupled to the first inner portion 278 by an extension 280 (e.g., as seen in FIGS. 7 and 9) of the one or more first pins 272 slidingly engaged in a groove 282 (e.g., as seen in FIGS. 7-9) of the first inner portion 278. In this way, the rotational and translational movement of the first outer portion 276, via actuation of the one or more first VGD actuators 270, the one or more first links 266, and the one or more first pins 272, causes the first inner portion 278 to translate in a direction the same as the translational direction of movement of the first outer portion 276.

[0049] Continuing with FIG. 6, as discussed herein the first VGD ring actuator assembly 264 may be coupled to the first VGD ring 260 via the first set of one or more VGD rods 262, such that translational movement of the first VGD actuator ring 268 in the first direction 210 and/or the second direction 212 causes translational movement of the first VGD ring 260 in a direction corresponding to a direction of the movement of the first VGD actuator ring 268. In particular, the first set of one or more VGD rods 262 may be coupled to the first inner portion 278 of the first VGD actuator ring 268, and thus as the first VGD actuator ring 268 (e.g., the first inner portion 278) translates in the first direction 210 the first VGD actuator ring 268 may apply a translational force in the first direction 210 onto the first VGD ring 260, via the first set of one or more VGD rods 262. Furthermore, the first VGD ring 260 may be positioned within the first diffuser inlet 214 of the first diffuser passage 130 and configured to block at least a portion of a volume of the first diffuser inlet 214 when the translational force is applied by the first VGD actuator ring 268 in the first direction 210. Additionally, as discussed herein, the first VGD ring 260 may be configured to enable adjustment of a volume of the first diffuser inlet 214 to provide consistent and stable flow of the working fluid through the first diffuser passage 130 (e g., less volume for higher velocity of working fluid, more volume for lower velocity of working fluid). The first VGD ring 260 may include one or more vanes 282 (e.g., airfoils) extending from the first VGD ring 260, with respect to the longitudinal axis 108. The one or more vanes 282 may be configured to guide a flow direction of a portion of the working fluid through the first diffuser inlet 214 (e.g., the first diffuser passage 130). Furthermore, the second wall 254 of the first diffuser passage 130 may include one or more openings 284 (e.g., hole, space, gap) each configured to receive a respective vane 282 of the one or more vanes 282. In particular, a geometry (e g., shape, form) of the opening 284 may correspond to a geometry of the respective vane 282. In this way, when the first VGD ring 260 is in an extended position within the first diffuser passage 130, such that the first VGD ring 260 substantially blocks at least a portion of the first diffuser inlet 214, each of the one or more vanes 282 may extend into (e.g., be within, be received by) a respective opening 284 of the one or more openings 284.

[0050] Furthermore, as illustrated in FIG. 6, the second compressor stage 116 may include one or more components of a second VGD ring assembly 286. The second VGD ring assembly 286 includes a second VGD ring 288 positioned at the second diffuser inlet 216, a second set of one or more VGD rods 290 (e.g., one or more nested rods) coupled to the second VGD ring 288, and a second VGD ring actuator assembly 292 coupled to the second set of one or more VGD rods 290 and configured to actuate the second VGD ring 288 in the first and the second directions 210, 212, via the second set of one or more VGD rods 290. The second VGD ring actuator assembly 292 may include one or more second links 294 (e.g., connectors), a second VGD actuator ring 296, one or more second VGD actuators 298. In particular, the second VGD actuator ring 296 may be coupled to the one or more second VGD actuators 298 by the one or more second links 294 via one or more second pins 300 (e.g., fasteners). The one or more second VGD actuators 298 may be configured to rotationally actuate (e.g., move) the one or more second links 294 about one or more respective second actuator axes 302 to cause rotational movement of the second VGD actuator ring 296 in the first rotational direction 218 and/or the second rotational direction 220. The second VGD actuator ring 296 may include a second upper portion 304 coupled to a second inner portion 306 of the second VGD actuator ring 296. In particular, a diameter of the second outer portion 304 may be larger than a diameter of the second inner portion 306, and the second outer portion 304 may be coupled to the second inner portion 306. In particular, the second outer portion 304 may be configured to slide (e.g., move) in the first rotational direction 218 and the second rotational direction 220 while the second inner portion 306 does not rotate in either the first rotational direction 218 or the second rotational direction 220. Furthermore, the one or more second links 294 may be coupled to the second outer portion 304 and may cause the second outer portion 304 to simultaneously rotate in the second rotational direction 220 and translate in the first direction 210 or to simultaneously rotate in the first rotational direction 218 and translate in the second direction. In addition, the second outer portion 304 may be coupled to the second inner portion 306 by an extension 308 (e.g., as seen in FIG. 7) of the one or more second pins 300 slidingly engaged in a groove 310 (e.g., as seen in FIGS. 7-9) of the second inner portion 306. In this way, the rotational and translational movement of the second outer portion 304, via actuation of the one or more second VGD actuators 298, the one or more second links 294, and the one or more second pins 300, causes the second inner portion 306 to translate in a direction corresponding to (e.g., generally the same as) the translational direction of movement of the second outer portion 304.

[0051] Continuing with FIG. 6, the second VGD ring actuator assembly 292 may be coupled to the second VGD ring 288 via the second set of one or more VGD rods 290, such that translational movement of the second VGD actuator ring 296 in the first direction 210 and/or the second direction 212 causes translational movement of the second VGD ring 288 in a direction corresponding to a direction of the movement of the second VGD actuator ring 296. In particular, the second set of one or more VGD rods 290 may be coupled to the second inner portion 306 of the second VGD actuator ring 296, and thus as the second VGD actuator ring 296 (e g., the second inner portion 306) translates in the first direction 210 the second VGD actuator ring 296 may apply a translational force in the first direction 210 onto the second VGD ring 288, via the second set of one or more VGD rods 290. Furthermore, the second VGD ring 288 may be positioned within the second diffuser inlet 216 of the second diffuser passage 140 and configured to block at least a portion of a volume of the second diffuser inlet 216 when the translational force is applied by the second VGD actuator ring 296 in the first direction 210. Additionally, as discussed herein, the second VGD ring 288 may be configured to enable adjustment of a volume of the second diffuser inlet 216 to provide consistent and stable flow of the working fluid through the second diffuser passage 140 (e.g., less volume for higher velocity of working fluid, more volume for lower velocity of working fluid).

[0052] As discussed herein, the first and/or the second VGD ring actuator assemblies 258, 286 may be installed within a plenum volume (e.g., space) of the CDS centrifugal compressor 32, which may be located in a space surrounding the first impeller 120 of the first compressor stage 114 of the CDS centrifugal compressor 32. In this way, the first and/or second VGD ring actuator assemblies 258, 286, may be positioned in an area that enables a desired compact length of the compressor shaft (e.g., a relatively short shaft length) for maintaining stable rotor dynamics and/or mitigating lateral and torsional vibrations of the compressor 32. In some embodiments, the first compressor stage 114 may be positioned between the second compressor stage 116 and the plenum volume, thus to enable actuation of the second VGD ring 288 located in the second compressor stage 116, the second set of one or more rods 290 may extend through one or more components of the first VGD ring actuator assembly 264, through the first wall 250, through the first VGD ring 260, through the second wall 252, through at least a portion of one or more deswirl vanes 136, and through the third wall 256 to couple the second VGD ring actuator assembly 292 to the second VGD ring 288. In particular, each VGD rod 290 of the second set of one or more VGD rods 290 may extend through a respective first opening 312 (e.g., channel, hole, passage) through the first inner portion 278 of the first VGD actuator ring 268, through a respective second opening 314 in the first wall 250, and through a respective third opening 316 in the first VGD ring 260. The one or more third openings 316 extending through the first VGD ring 260 may each correspond with a respective vane 282 of the one or more vanes 282. In this way, the second set of one or more VGD rods 290 may pass through (e.g., extend through) the first diffuser passage 130 via the one or more vanes 282 without taking up significant or any additional space (space outside of the one or more vanes 282) within the diffuser passage 130, and thus not cause flow disruptions due to aeraulic losses around the second set of one or more VGD rods 290. In particular, a geometry (e.g., shape, form) of the one or more vanes 282 may optimize a flow of the working fluid through the first diffuser inlet 214. Specifically, the one or more vanes 282 may totally surround (e.g., encase, enclose, encompass) a portion of the second set of one or more VGD rods 290 that extends through the first diffuser passage 130. In addition, each VGD rod 290 of the second set of one or more VGD rods 290 may extend through a respective fourth opening 318 in the second wall 252. The one or more fourth openings 318 may include at least a portion of a respective opening 284 of the one or more openings 284 that each receive a respective vane 282. Furthermore, each VGD rod 290 of the second set of one or more VGD rods 290 may extend through a fifth opening 320 extending through one or more of the deswirl vanes 136. In particular, the one or more deswirl vanes 136 of the second inlet chamber 134 may totally surround (e.g., encase) a portion of the second set of the one or more VGD rods 290 that extends through the second inlet chamber 134. In this way, the second set of one or more VGD rods 290 may not cause flow disruptions due to aeraulic losses around the portion of the second set of one or more VGD rods 290 extending through the second inlet chamber 134. Furthermore, each VGD rod 290 of the second set of one or more VGD rods 290 may extend through a sixth opening 322 of the third wall 256 and couple to the second VGD ring 288.

[0053] As discussed herein, the compact VGD assemblies of the CDS centrifugal compressor 32 of the present disclosure produce a compact VGD regulation system 200 for the CDS centrifugal compressor 32 that enables independent operation (e.g., control) of the VGD actuator ring assemblies to improve efficiency and performance of the CDS centrifugal compressor 32, even at partial load conditions, by reducing instability or inconsistency of flow within the CDS centrifugal compressor 32 and preventing surges and/or stalls, while also reducing undesirable noise and vibration. In addition, the compact VGD regulation system 200 described herein enables two VGD ring actuator assemblies to independently operate and actuate a respective VGD ring associated with a respective diffuser passage of the CDS centrifugal compressor 32. In particular, the compact VGD regulation system 200 enables the two independent VGD ring actuator assemblies to each control a position of a respective VGD ring and enables independent control of each respective VGD ring even at compressor stages higher than a first compressor stage, such as the second compressor stage 116, while maintaining a desired length (e.g., compactness) of each stage. Thus, the compact VGD regulation system 200 may enable efficient control and/or regulation of a capacity of the CDS centrifugal compressor 32 while also maintaining a relatively compact (e g., substantially short) overall shaft length (e g., axial length) of the CDS centrifugal compressor 32 by positioning (e.g., installing) the two VGD ring actuator assemblies in the plenum volume (e.g., space) of the CDS centrifugal compressor 32. As discussed herein, the plenum volume may be located in a space surrounding the first impeller 120 of the first compressor stage 114 of the CDS centrifugal compressor 32. In this way, the two VGD ring actuator assemblies may be positioned in an area that optimizes a length of the compressor shaft and/or maintain a relatively short shaft length. The compact VGD regulation system 200 may also include a system of nested rods (e.g., nested pins) extending from the second VGD ring actuator assembly 292 to enable independent control of translation (e.g., movement, axial translation) of the second VGD ring 288 of the second compressor stage 116. In particular, the second set of one or more VGD rods 290 (e g., the one or more nested rods) may be configured to pass through each diffuser passage (e.g., the first and the second diffuser passage 130, 140) via one or more vanes (e.g., the one or more vanes 282, the one or more deswirl vanes 136) of the CDS centrifugal compressor 32, and thus mitigate any inefficiency and/or negative effects (e.g., via obstruction of the diffuser passage) on flow of the working fluid that may be caused by the one or more rods passing through each of the diffuser passages.

[0054] It should be appreciated, that even though the present disclosure illustrates a dual stage centrifugal compressor, in some embodiments, the compact VGD regulation system 200 may be included in a centrifugal compressor with more or less number of compressor stages (e.g., one stage, three stages, five stages, eight stages, etc.). In some embodiments, the compact VGD regulation system 200 may include a VGD ring actuator assembly coupled to a VGD ring via a set of one or more rods for each compressor stage of the compressor. In some embodiments, a diameter of each VGD ring of the compact VGD regulation system may be the same, and the diameter of each VGD ring may correspond to a diameter of a respective VGD actuator ring.

[0055] With the foregoing in mind, FIGS. 7-9 illustrate the compact VGD regulation system 200 (e.g., the first VGD ring assembly 258, the second VGD ring assembly 286) in various operational positions, such as an extend positon and a retracted position. In particular, FIG. 7 is a cross-sectional side view of an embodiment of the compact VGD regulation system 200 of the CDS centrifugal compressor 32. In particular, FIG. 7 illustrates both the first and the second compact VGD assemblies 258, 286 in a retracted position, such that the first and the second VGD rings 260, 288 are not substantially extended into the first and the second diffuser inlets 214, 216, respectively. In the retracted position, the first VGD ring 260 includes the one or more vanes 282 that extend into the first diffuser inlet 214 to provide for a nested passage (e.g., opening, channel) for the second set of one or more VGD rods 290 to pass through and extend into the first diffuser passage 130 surrounded by (e.g., nested within) the one or more vanes 282. In addition, in the retracted position, the first VGD ring 260 is positioned within an opening 324 (e.g., channel, hole) of the first wall 250, so as to not block the first diffuser inlet 214. In particular, a geometry (e.g., shape, form) of the opening 324 of the first wall 250 may correspond to a geometry of the first VGD ring 260. Similarly, in the retracted position, the second VGD ring 288 is positioned with an opening 326 (e.g., channel, hole) of the third wall 256, so as to not block the second diffuser inlet 216. In particular, a geometry (e.g., shape, form) of the opening 326 of the third wall 256 may correspond to a geometry of the second VGD ring 288.

[0056] FIG. 8 is a cross-sectional side view of an embodiment of the compact VGD regulation system 200 of the CDS centrifugal compressor 32. In particular, FIG. 8 illustrates the first VGD ring assembly 258 in an extended position, while the second VGD ring assembly 286 is in the retracted positon. In particular, in the extended positon, the first VGD ring 260 is extended from the opening 324 of the first wall 250 and into the first diffuser inlet 214. In this way, in the extended position, the first VGD ring 260 may block at least a portion of the first diffuser inlet 214 (e.g., decrease a volume of the first diffuser inlet 214). In the extended position, at least a portion of the one or more vanes 282 of the first VGD ring may extend into the one or more openings 284 of the second wall 252, enabling the first VGD ring to translate into the first diffuser inlet 214 while the second set of one or more VGD rods 290 remain surrounded (e.g., encased) within the one or more vanes 282. In particular, the one or more vanes 282 may translate relative to the second set of one or more VGD rods 290, when the first VGD ring 260 is actuated by the first VGD ring actuator assembly 264. [0057] FIG. 9 is a cross-sectional side view of an embodiment of the compact VGD regulation system 200 of the CDS centrifugal compressor 32. In particular, FIG. 9 illustrates the second VGD ring assembly 286 in an extended position, while the first VGD ring assembly 258 is in the retracted positon. In particular, in the extended positon, the second VGD ring 288 is extended from the opening 326 of the third wall 256 and into the second diffuser inlet 216. In this way, in the extended position, the second VGD ring 288 may block at least a portion of the second diffuser inlet 216 (e.g., decrease a volume of the second diffuser inlet 216). In particular, the second set of one or more VGD rods 290 may translate relative to the one or more vanes 282 of the first VGD ring 260, when the second VGD ring 288 is actuated by the second VGD ring actuator assembly 292. In addition, FIGS. 7-9 illustrate the second set of one or more VGD rods 290 extending through the first opening 312 of the first inner portion 278 of the first VGD actuator ring 268, through the second opening 314 in the first wall 250, and through the third opening 316 in the first VGD ring 260. In particular, the one or more third openings 316 extending through the first VGD ring 260 may each correspond with a respective vane 282 of the one or more vanes 282. In this way, the second set of one or more VGD rods 290 may pass through (e.g., extend through) the first diffuser passage 130 via the one or more vanes 282, and thus not cause flow disruptions due to aeraulic losses around the second set of one or more VGD rods 290. Specifically, the one or more vanes 282 may totally surround (e.g., encase) a portion of the second set of one or more VGD rods 290 that is extending through the first diffuser passage 130. In addition, FIGS. 7-9 illustrate the second set of one or more VGD rods 290 extending through the fourth opening 318 in the second wall 252 and through the fifth opening 320 extending through the one or more deswirl vanes 136. In particular, the one or more deswirl vanes 136 of the second inlet chamber 134 may totally surround (e.g., encase) a portion of the second set of the one or more VGD rods 290 that is extending through the second inlet chamber 134. In this way, the second set of the one or more VGD rods 290 may not cause flow disruptions due to aeraulic losses around the portion of the second set of the one or more VGD rods 290 extending through the second inlet chamber 134. Furthermore, FIGS. 7-9 illustrate the second set of the one or more VGD rods 290 extending through the sixth opening 322 of the third wall 256 and coupling to the second VGD ring 288.

[0058] The present disclosure may provide one or more technical effects useful in the operation of an HVAC&R system. For example, the HVAC&R system may include a compact VGD regulation system for multistage centrifugal compressors, which may provide independently operated (e.g., controlled) VGD components to improve efficiency and performance of the multistage centrifugal compressor, even at partial load conditions, by reducing instability or inconsistency of flow within the multistage centrifugal compressor and preventing surges and/or stalls. The compact VGD regulation system may also reduce undesirable noise and vibration of the multistage centrifugal compressor during operation. In addition, the present disclosure may provide the compact VGD regulation system for regulating compressor capacity (e.g., multistage centrifugal compressor capacity) by enabling two or more VGD ring actuator assemblies each to independently actuate a respective VGD ring disposed within a respective diffuser inlet of a diffuser passage of a stage of the multistage centrifugal compressor. In particular, each of the VGD ring actuator assemblies translate the respective VGD ring and independently control a position of the respective VGD ring of the multistage centrifugal compressor. In addition, each of the two or more VGD ring actuator assemblies may be positioned (e.g., installed) in a plenum volume (e g., space) of the multistage centrifugal compressor, which may be located in a space surrounding an initial impeller of a first compressor stage of the multistage centrifugal compressor. In this way, the two or more VGD ring actuator assemblies may be positioned in an area that optimizes a length of the compressor shaft by enabling a relatively compact (e.g., substantially short) overall shaft length (e.g., axial length), thus maintaining stable rotor dynamics, or management of lateral and torsional vibrations of the multistage centrifugal compressor. Furthermore, the compact VGD regulation system may include a system of nested rods (e.g., nested pins) extending from one or more of the VGD ring actuator assemblies to enable independent control of translation (e.g., movement, axial translation) of each respective VGD ring, such as VGD rings positioned at stages beyond a first stage of the multistage centrifugal compressor (e.g., second stage, third stage, etc.). In addition, one or more rods of the nested rods may be configured to pass through (e.g., translate within) each diffuser passage via a series of openings in one or more fixed vanes of the multistage centrifugal compressor, and thus prevent any inefficiency and/or negative effects (e.g., via obstruction of the diffuser passage) on fluid flow that may be caused by the one or more rods passing through the diffuser passage.

[0059] While only certain features and embodiments of the present disclosure have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. It is, therefore, to be noted that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the present disclosure. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode of carrying out the present disclosure, or those unrelated to enabling the claimed embodiments). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

[0060] 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).

Claims

CLAIMS:

1. A heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system, comprising: a vapor compression circuit; and a compressor fluidly coupled to the vapor compression circuit, the compressor comprising: a first compressor stage comprising a first diffuser passage; a second compressor stage comprising a second diffuser passage; and a variable geometry diffuser (VGD) regulation system, comprising: a first VGD ring disposed within a first diffuser inlet of the first diffuser passage, the first VGD ring comprising a vane; a second VGD ring disposed within a second diffuser inlet of the second diffuser passage; and a VGD actuator ring coupled to the second VGD ring by at least one rod, wherein the at least one rod extends through the first VGD ring and the vane before coupling to the second VGD ring.

2. The HVAC&R system of claim 1, wherein the VGD actuator ring is a second VGD actuator ring, and wherein the VGD regulation system comprises a first VGD actuator ring coupled to and configured to actuate the first VGD ring.

3. The HVAC&R system of claim 2, the first VGD ring and the second VGD ring are each configured to move between a retracted position and an extended position.

4. The HVAC&R system of claim 3, wherein the first diffuser inlet is configured to have a first volume when the first VGD ring is in the retracted position and a second volume when the first VGD ring is in the extended position, the first volume being greater than the second volume.

5. The HVAC&R system of claim 3, wherein the second diffuser inlet is configured to have a first volume when the second VGD ring is in the retracted position and a second volume of the second diffuser inlet when the second VGD ring is in the extended position, wherein the first volume is greater than the second volume.

6. The HVAC&R system of claim 3, wherein the first diffuser passage comprises a diffuser panel, and wherein the vane is configured to extend into an opening within the diffuser panel when the first VGD ring is in the extended position.

7. The HVAC&R system of claim 3, wherein the at least one rod is configured to translate relative to the vane when the second VGD ring is actuated between the extended position and the retracted position, between the retracted position and the extended position, or both.

8. The HVAC&R system of claim 3, wherein the first VGD ring is configured to be in the extended position when the second VGD ring is in the retracted position.

9. The HVAC&R system of claim 1, wherein the vane encloses at least a portion of the at least one rod.

10. A variable geometry diffuser (VGD) regulation system for a compressor of a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system, comprising: a first VGD ring positioned adjacent to a first diffuser passage of the compressor, the first VGD ring comprising a vane; a second VGD ring positioned at least partially within a second diffuser passage of the compressor; and a VGD ring assembly coupled to the first VGD ring and the second VGD ring, wherein the VGD ring assembly is coupled to the second VGD ring by at least one rod that extends through the first VGD ring and the vane before coupling to the second VGD ring.

11. The VGD regulation system of claim 10, wherein the VGD ring assembly comprises a first VGD actuator ring coupled to and configured to actuate the first VGD ring between a first retracted position and a first extended position and a second VGD actuator ring configured to couple to and actuate the second VGD ring between a second retracted position and a second extended position.

12. The VGD regulation system of claim 11, wherein the first diffuser passage comprises a diffuser panel and the vane is configured to extend into an opening within the diffuser panel when the first VGD ring is in the first extended position.

13. The VGD regulation system of claim 11, wherein the vane encloses at least a portion of the at least one rod, and wherein the at least one rod is configured to translate relative to the vane when the second VGD ring is actuated via the second VGD actuator ring.

14. The VGD regulation system of claim 11, wherein the VGD ring assembly comprises: a first set of actuators configured to couple to the first VGD actuator ring; a second set of actuators configured to couple to the second VGD actuator ring; a first set of links coupling the first set of actuators to the first VGD actuator ring; and a second set of links coupling the second set of actuators to the second VGD actuator ring, wherein the first set of actuators are configured to apply a rotational force to the first VGD actuator ring via the first set of links to cause the first VGD ring to actuate between the first retracted position and the first extended position and the second set of actuators are configured to apply a rotational force to the second VGD actuator ring via the second set of links to cause the second VGD ring to actuate between the second retracted position and the second extended position.

15. The VGD regulation system of claim 14, wherein the first VGD actuator ring comprises a first outer ring portion coupled to a second inner ring portion via one or more grooves, wherein the one or more grooves are configured to convert the rotational force to a translational force causing the first VGD ring to extend into or retract out of the first diffuser passage.

16. A heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system, comprising: a variable geometry diffuser (VGD) regulation system for a compressor of the HVAC&R system, comprising: a first VGD ring comprising a vane and positioned adjacent to a first diffuser passage of the compressor; a first VGD ring actuator assembly coupled to the first VGD ring and configured to actuate the first VGD ring to extend into or retract out of the first diffuser passage; a second VGD ring positioned at least partially within a second diffuser passage of the compressor; and a second VGD ring actuator assembly coupled to the second VGD ring and configured to actuate the second VGD ring to extend into or retract out of the second diffuser passage, wherein the second VGD ring actuator assembly is coupled to the second VGD ring by at least one rod that extends through the first VGD ring and the vane before coupling to the second VGD ring; and a control system communicatively coupled to the VGD regulation system, wherein the control system is configured to control actuation of the first VGD ring and the second VGD ring.

17. The HVAC&R system of claim 16, wherein the control system is configured to control actuation of the first VGD ring independent of actuation of the second VGD ring.

18. The HVAC&R system of claim 16, wherein the second VGD ring actuator assembly comprises: a VGD actuator ring configured to rotate relative to a central axis extending through the compressor, wherein the VGD actuator ring comprises an outer ring portion moveably coupled to an inner ring portion; a set of actuators configured to couple to and cause rotation of the outer ring portion of the VGD actuator ring; a set of pins extending through the outer ring portion and slidingly engaging with one or more grooves of the inner ring portion; and a set of links coupling the set of actuators to the set of pins, wherein the set of actuators are configured to apply a rotational force to the outer ring portion of the VGD actuator ring via the set of links and the set of pins to cause the second VGD ring to actuate to extend into or retract out of the second diffuser passage via the at least one rod.

19. The HVAC&R system of claim 18, wherein the set of pins are configured to convert the rotational force to a translational force causing translation of the inner ring portion, the at least one rod, and the second VGD ring.

20. The HVAC&R system of claim 19, wherein the vane surrounds the at least one rod, and wherein the at least one rod is configured to translate relative to the vane when the second VGD ring is actuated via the second VGD ring actuator assembly.