EP4680864A1

EP4680864A1 - Compact variable geometry regulation system of a compressor for a heating, ventilation, air conditioning, and/or refrigeration system

Info

Publication number: EP4680864A1
Application number: EP24781543.4A
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: 2023-03-24
Filing date: 2024-03-18
Publication date: 2026-01-21
Also published as: WO2024205972A1; KR20260010680A; TW202441118A; CN121079506A

Abstract

A heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system 10 includes a vapor compression circuit 14 and a compressor 32 fluidly coupled to the vapor compression circuit 14. The compressor 32 includes a diffuser passage 130 comprising a diffuser inlet 214, and a variable geometry diffuser (VGD) regulation system 200. The VGD regulation system 200 includes a VGD housing, a VGD ring 204 disposed at the diffuser inlet 214, wherein at least a portion of the VGD ring 204 is within the VGD housing, and a VGD ring actuator 206 coupled to VGD ring 204, wherein the VGD ring actuator 206 is configured to actuate the VGD ring 204 between a retracted position and an extended position.

Description

COMPACT 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. 63/454,367, entitled “COMPACT VARIABLE GEOMETRY REGULATION SYSTEM OF A COMPRESSOR FOR A HEATING, VENTILATION, AIR CONDITIONING, AND/OR REFRIGERATION SYSTEM,” filed March 24, 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 diffuser passage comprising a diffuser inlet, and a variable geometry diffuser (VGD) regulation system. The VGD regulation system includes a VGD housing, a VGD ring disposed at the diffuser inlet, wherein at least a portion of the VGD ring is within the VGD housing, and a VGD ring actuator coupled to VGD ring, wherein the VGD ring actuator is configured to actuate the VGD ring between a retracted position and an extended position relative to the VGD housing.

[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 VGD ring casing positioned at a diffuser passage of the compressor, and a VGD ring coupled to the VGD ring casing and disposed adjacent to a diffuser inlet of the diffuser passage, wherein at least a portion of the VGD ring is within the VGD ring casing. The VGD regulation system also includes a VGD ring actuator coupled to the VGD ring, wherein the VGD ring actuator is configured to extend through at least a portion of the VGD ring casing to couple to the 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 VGD ring housing configured to be positioned at a diffuser passage of the compressor, wherein the VGD ring housing comprises a gap formed from a first portion of the VGD housing being offset from a second portion of the VGD housing. The VGD regulation system also includes a VGD ring coupled to the VGD ring housing and configured to be disposed adjacent to a diffuser inlet of the diffuser passage, wherein at least a portion of the VGD ring is within the gap, and a VGD ring actuator assembly coupled to the VGD ring, wherein the VGD ring actuator assembly extends through at least a portion of the VGD ring housing to couple to the VGD ring. The HVAC&R system also includes a controller communicatively coupled to the VGD regulation system and configured to control actuation of the VGD ring between a retracted position and an extended position relative to the VGD ring housing, wherein the extended position is associated with at least a portion of the VGD ring positioned exterior to the VGD ring housing.

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 VGD ring assembly of the centrifugal compressor of the HVAC&R system, in accordance with an aspect of the present disclosure;

[0015] FIG. 7 is a perspective view of an embodiment of a VGD ring casing of a VGD ring actuator assembly of the centrifugal compressor of the HVAC&R system, in accordance with an aspect of the present disclosure;

[0016] FIG. 8 is a perspective view of an embodiment of a VGD ring of a VGD ring actuator assembly of the centrifugal compressor of the HVAC&R system, in accordance with an aspect of the present disclosure;

[0017] FIG. 9 is a cross-sectional perspective view of an embodiment of a VGD ring actuator assembly of the centrifugal compressor of the HVAC&R system, in accordance with an aspect of the present disclosure;

[0018] FIG. 10 is a cross-sectional perspective view of an embodiment of a VGD ring actuator assembly of the centrifugal compressor of the HVAC&R system, in accordance with an aspect of the present disclosure; and

[0019] FIG. 11 is a perspective view of an embodiment of a VGD ring including the fluid grooves, 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 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.

[0022] 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 compressor 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.

[0023] 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 compressor 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.

[0024] In particular, the VGD regulation system may include a VGD actuator (e.g., VGD actuator assembly, VGD actuator system) 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 prevent 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).

[0025] 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.

[0026] Thus, it is now recognized that a VGD regulation system (e.g., VGD system) is desirable for multistage centrifugal compressors that include independently operated (e.g., controlled) VGD components to improve efficiency and performance of the multistage centrifugal compressors, 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 one or more VGD actuator systems (e.g., mechanical actuator system, hydraulic actuator system) 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 the one or more VGD actuator systems 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, in some embodiments, the one or more actuator systems may be positioned (e.g., installed) in a space outside of the one or more compressor stages of the multistage centrifugal compressor, such as in and/or external to (e.g., exterior surface of) a pump casing (e.g., volute) of the multistage centrifugal compressor. Moreover, in certain embodiments, the one or more actuator systems may be operated via controllably transmitted fluid mass, wherein compact fluid ports may be incorporated into each of the one or more compressor stages of the multistage centrifugal compressor. In this way, the one or more VGD actuator systems may be compact and/or positioned in an area that optimizes a length of the compressor shaft and/or maintains a relatively short shaft length.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.).

[0036] 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 one or more actuator systems 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 one or more actuator systems 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, in some embodiments, the one or more actuator systems may be positioned (e.g., installed) external to a pump casing (e.g., volute casing) of the multistage centrifugal compressor, which may be located in a space outside of the one or more compressor stages of the multistage centrifugal compressor. Moreover, in certain embodiments, the one or more actuator systems may be operated via controllably transmitted fluid pressure, wherein compact fluid ports may be incorporated into each of the one or more compressor stages of the multistage centrifugal compressor. In this way, the one or more VGD actuator systems may be compact and/or positioned in an area that optimizes a length of the compressor shaft and/or maintain a relatively short shaft length.

[0037] 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, which is illustrated as substantially parallel with 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. Additionally or alternatively, it should be understood that HVAC&R system 10 and its respective components may be described herein with respect to the axis 106 and one or more radial directions 254 (illustrated in FIG. 6) extending radially from the axis 106. Furthermore, the longitudinal axis 108 may be representative of an axial direction and the vertical axis 110 may be representative of a radial direction. As will be understood, the compressor 32 may be positioned in different orientations in which, for example, the vertical axis 110 is not vertical. In addition, it should be appreciated that the compressor 32 may be installed and/or operated in any suitable position (e.g., vertical, horizontal, at any suitable operational angle) and thus the axis 106 may extend at any suitable angle with respect to the illustrated longitudinal axis 108, the vertical axis 1 10, the lateral axis 1 12, or any combination thereof.

[0038] In the illustrated embodiment, the compressor 32 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.

[0039] 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 (e.g., from the evaporator 38, from the intermediate vessel 70) to flow along a working fluid flow path 126 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 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, the first diffuser inlet 214 positioned upstream of the first diffuser passage 130 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, the second diffuser inlet 216 positioned upstream of the second diffuser passage 140 relative to a working fluid flow through the first diffuser passage 130. Additionally, the working fluid may be directed from the second diffuser passage 140 to a volute 144 (e.g., pump casing) 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.

[0040] 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 (e.g., the first diffuser inlet 214, the second diffuser inlet 216) 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.

[0041] In 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, and a VGD ring actuator assembly 206 (e g., VGD ring actuator system). The VGD ring 204 and VGD ring actuator assembly 206 are described in more detail in FIGS. 6-11. Furthermore, each stage of the one or more compressor stages 104 may include the VGD ring 204 positioned at a diffuser inlet (e.g., being positioned at a diffuser inlet may include being positioned close enough to the diffuser inlet such that sufficient kinetic energy remains to reaccelerate the fluid locally) of a respective diffuser passage (e.g., the first and/or second diffuser inlet 214, 216 of the first and/or second diffuser passage 130, 140). It should be appreciated that, in some embodiments, the VGD ring 204 may be positioned at any point along a length of a respective diffuser passage (e.g., the first length 146 of the first diffuser passage 130, the second length 148 of the second diffuser passage 140) such that a portion of working fluid leaving (e.g., exiting) a respective impeller (e.g., the first impeller 120, the second impeller 122) may pass across the VGD ring 204 prior to traveling a total length of the respective diffuser passage.

[0042] As discussed herein, the VGD ring 204 may be configured to vary a size (e.g., volume) of an inlet (e.g., or portion) 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, in some embodiments, 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 210) 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. It should be understood, that in some embodiments, the VGD ring 204 may be configured to translate (e.g., axially translate) in the second direction 212, 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 the first direction 210 (e.g., a direction generally opposite the first direction 210) with respect to the longitudinal axis 108, to cause the respective inlet of the diffuser passage to increase in size (e.g., volume).

[0043] 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. Furthermore, the present embodiments include the VGD ring 204 positioned at or substantially near the diffuser inlet of a respective diffuser passage, however, it should be appreciated that the VGD ring 204 may be configured to be installed at any suitable point along a length of the respective diffuser passage so as to enable efficient control over a flow rate (e.g., velocity) of the working fluid within the diffuser passage and/or prevent back flow of the working fluid during low speed and/or low capacity operations of the compressor 32 by adjusting the respective axial position of the VGD rings 204 with in the diffuser passage.

[0044] 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 ring assemblies 202 (e.g., actuators) to independently regulate an 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 32 even at varying operational conditions (e.g., low capacity operation, low working fluid velocity operations, low compressor speed operations, partial load conditions).

[0045] 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.

[0046] 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 actuators (e.g., VGD ring actuator assemblies 206) to cause rotation of the respective VGD ring 204 and thus cause translation of the respective VGD ring 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 rings 204 may be transformed to a translational force to translate (e.g., adjust, move) the one or more VGD rings 204 relative to the axis 106 (e.g., in the first direction 210 and/or the second direction 212).

[0047] The control system 222 may be configured to control rotational movement and/or adjustment of the one or more VGD rings 204 based on one or more operational conditions of the vapor compression system, and therefore control translational movement and a position of the VGD rings 204 within the respective diffuser inlet based on the one or more operational conditions. 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 222 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.

[0048] 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 detects 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 ring actuator assemblies 206 to adjust a position of the one or more VGD rings 204 based on the flow condition of the compressor 32 (e.g., based on the received data and/or indication).

[0049] 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.

[0050] With the foregoing in mind, FIG. 6 is a perspective view of an embodiment of the VGD ring assembly 202 of the centrifugal compressor 32 of the HVAC&R system 10. In particular, as discussed herein, the VGD ring assembly 202 may be positioned at or relatively near (e.g., adjacent to) each diffuser inlet of each diffuser passage of the compressor 32. Furthermore, the VGD ring assembly 202 may include a VGD ring actuator assembly 206 coupled to a VGD ring 204. The VGD ring actuator assembly 206 may include a VGD ring casing 304 (e.g., diffuser plate, nozzle base plate, VGD housing, VGD ring housing) that is configured to enclose and/or house at least a portion of the VGD ring 204, and a VGD ring actuator 306 (not shown in FIG. 6) configured to couple to and actuate the VGD ring 204. The VGD ring actuator 306 will be described in more detail below with respect to FIGS. 9-11. The VGD ring casing 304 may include a surface 308 (e.g., face, side) configured to include (e.g., house, enclose) at least a portion of the VGD ring 204. With respect to FIGS. 5 and 6, and as discussed herein, the 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 114 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. In other words, the VGD ring casing 304 may be positioned at (e.g., adjacent to, offset from, at least partially form, be integral with) the first wall 250 and/or the second wall 252 of the first diffuser passage 130. 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. For simplicity and ease of illustration, some components of the centrifugal compressor 32, such as the first wall 250, the second wall 252, and the outer edge 255 of the second wall 252, are not shown in FIG. 6 to better illustrate internal components. Moreover, 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. Furthermore, the second compressor stage 116 may include the second impeller 122 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 simplicity and ease of illustration, some components of the centrifugal compressor 32, such as 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 216 and towards the volute 144 of the compressor 32.

[0051] As illustrated in FIG. 5, a respective VGD ring casing 304 and a respective VGD ring 204 may be positioned at each diffuser passage of the compressor 32, such as a first VGD ring casing 310 and a respective VGD ring 204 of a first VGD ring assembly 300 positioned at the first diffuser passage 130 and a second VGD ring casing 312 and a respective VGD ring 204 of a second VGD ring assembly 302 positioned at the second diffuser passage 140. In particular, the first VGD ring casing 310 (and the respective VGD ring 204) may be positioned substantially within the first wall 250 of the compressor 32 and in a space that surrounds (e.g., is outside of) the first impeller 120, with respect to the axis 106. While, the second VGD ring casing 312 (and the respective VGD ring 204) may be positioned within the third wall 256 of the compressor 32 and in a space that substantially surrounds (e.g., is outside of) the second impeller 122. For example, a portion of the first wall 250 and/or a portion of the third wall 256 may include the surface 308 of the VGD ring assembly 202 (e.g., the first and/or second VGD ring casing 310, 312), which additionally houses and/or includes the VGD ring 204. In some embodiments, the surface 308 of the VGD ring assembly 202 may extend substantially the entire length of the respective diffuser passage (e.g., the first length 146 of the first diffuser passage 130, the second length 148 of the second diffuser passage 140). In addition, a respective VGD ring 204 may be positioned (e.g., disposed) at (e.g., adjacent to, offset from, to be extendable within) the respective diffuser inlet (e.g., the first and/or second diffuser inlet 214, 216).

[0052] Furthermore, each of the first and second VGD ring assemblies 300, 302 may include a respective VGD ring actuator assembly 206 configured to couple to the respective VGD ring 204 and cause the respective VGD ring 204 to rotate in a first rotational direction 314 or a second rotational direction 316 about the axis 106. In addition, due to the coupling of the VGD ring 204 within the VGD ring casing 304, a rotational motion of the VGD ring 204 caused by the VGD ring actuator 306 may be converted to a translational motion of the VGD ring 204 in the first and/or second directions 210, 212. In this way, the each of the VGD ring assemblies 202 may be positioned within the compressor 32 such that each of the VGD rings 204 may extend into and/or retract out of a respective diffuser inlet (e.g., the first and/or second diffuser inlet 214, 216) of each stage of the one or more compressor stages 104 of the compressor 32. Thus, each of the VGD ring assemblies 202 may be independently operate and independently adjust a respective volume of one or more diffuser passage inlets (e.g., the first diffuser inlet 214, the second diffuser inlet 216) to provide consistent and stable flow of the working fluid through the one or more diffuser passages. Therefore, the VGD ring assemblies 202 may enable the compressor 32 to 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. [0053] FIG. 7 is a perspective view of an embodiment of the VGD ring casing 304 (e.g., diffuser plate, nozzle base plate) of the VGD ring actuator assembly 206 (e.g., the VGD ring assembly 202) of the centrifugal compressor 32 of the HVAC&R system 10. With respect to traditional operations, the VGD ring casing 304, in accordance with present embodiments, may provide for functionality like that of both a diffuser plate and a VGD casing combined. As discussed herein, the VGD ring casing 304 may include the surface 308 (e.g., face, side) configured to house and/or enclose the VGD ring 204. As such, the surface 308 may include a gap 318 (e.g., opening, hole) configured to receive the VGD ring 204. For example, a shape (e.g., geometry) and/or volume of the gap 318 may substantially correspond to a shape (e.g., geometry) and/or volume of the VGD ring 204. In addition, the shape and/or the volume of the gap 318 may be slightly larger than the shape and/or the volume of the VGD ring 204, such that the VGD ring 204 may fit within (e.g., inside of) the gap 318. The gap 318 (e.g., thus the VGD ring 204) may be positioned within the VGD ring casing 304 such that a first portion 326 of the VGD ring casing 304 is positioned circumferentially(e.g., concentrically) outside of the gap 318, with respect to the axis 106, and a second portion 328 of the VGD ring casing 304 is positioned circumferentially inside of the gap 318, with respect to the axis 106 (e.g., the first portion 326 being offset from the second portion 328). The gap being a ring-shaped void (e.g., empty space) configured to house the VGD ring 204. In some embodiments, the first portion 326 may have a larger volume (e.g., larger cross-sectional area) than the second portion 328. In addition, in some embodiments, the VGD ring casing 304 may be substantially circular in shape, with respect to the axis 106. For example, in some embodiment, the axis 106 may extend through a center 320 of the VGD ring casing 304, and the VGD ring casing 304 may include a radius 322 that extends from the center 320 to an outer edge 324 of the surface 308, with respect to the axis 106.

[0054] Furthermore, the gap 318 may include a first side wall 330, a second side wall 332 opposite the first side wall 330, and a third side wall 334 coupling the first side wall 330 and the second side wall 332. The first side wall 330 and the second side wall 332 may be spaced a distance 336 apart from one another, the distance 336 being substantially equal to a radial length 338 of the third side wall 334. Furthermore, a depth 340 of the gap 318 may correspond to a length 341 of the first side wall 330 and/or the second side wall 332. It should be understood, that the distance 336 and/or the depth 340 of the VGD ring casing 304 may be determined based on a size (e.g., shape, volume, measurements) of a VGD ring 204 that the gap 318 may house. In addition, during installation, one or more gaskets may be included between the VGD ring 204 and the first side wall 330 and/or the second side wall 332 so as to sealingly couple the VGD ring 204 to the VGD ring casing 304. The use of the term sealingly couple is intended to mean that essentially no fluid and/or gas may pass between the VGD ring 204 and the first side wall 330 and/or the second side wall 332 of the gap 318. Including the one or more gaskets may improve an aeraulic efficiency of the compressor 32 by substantially mitigating any gas bypass around the VGD ring 204 and/or local turbulence caused by open space between the VGD ring 204 and the VGD ring casing 304.

[0055] In addition, as discussed herein, the VGD ring casing 304 may enable rotational movement of the VGD ring 204 in the first rotational direction 314 and/or the second rotational direction 316 about the axis 106 to be converted into translational movement of the VGD ring 204 in the first direction 210 and/or the second direction 212. As discussed herein, the translational movement of the VGD ring 204 in the first direction 210 may cause the VGD ring 204 to extend into the respective diffuser inlet (e.g., decrease a volume of the respective diffuser inlet), while translational movement of the VGD ring 204 in the second direction 212 may cause the VGD ring 204 to retract out of the respective diffuser inlet (e.g., increase a volume of the respective diffuser inlet). Furthermore, the VGD ring 204 may translate axially with respect to the axis 106 and extend out of the gap 318 of the VGD ring casing 304. In other words, as the VGD ring 204 translates in the first direction 210, a portion of the VGD ring 204 that is enclosed within the gap 318 (e.g., abutting the first and/or second side walls 330, 332) may decrease, while a portion of the VGD ring 204 that is within the respective diffuser inlet may increase. On the other hand, as the VGD ring 204 translates in the second direction 212, the portion of the VGD ring 204 that is enclosed within the gap 318 (e.g., abutting the first and/or second side walls 330, 332) may increase, while the portion of the VGD ring 204 that is within the respective diffuser inlet may decrease.

[0056] To enable the rotational movement of the VGD ring 204 to be converted into the translational movements (e.g., in the first and/or second directions 210, 212), the VGD ring casing 304 may include one or more casing grooves 342 (e.g., channels, furrow) formed within the first and/or the second side walls 330, 332 of the gap 318. In particular, as illustrated in FIG. 7. The one or more casing grooves 342 may be formed within the second side wall 332 of the gap 318. The one or more casing grooves 342 may be configured to facilitate the conversion of rotational movement of the VGD ring 204 into translational movement of the VGD ring 204. For example, in some embodiments, the one or more casing grooves 342 may include one or more rolling elements 344 (e.g., ball-bearings, balls, roller-bearing, wheels). The one or more rolling elements 344 may be positioned within the casing grooves 342 and each rolling element may be configured to rollingly engage with a respective casing groove 342 of the VGD ring casing 304. In other words, each rolling element 344 may be positioned with in a respective casing groove 342 such that a portion of the rolling element 344 is within the casing groove 342, and the rolling element 344 may rotate (e.g., roll) within the casing groove 342 while maintaining a same position within the casing groove 342. In addition, the one or more casing grooves 342 may extend at an angle with respect to the axis 106. In particular, a first end 346 of a casing groove 342 of the one or more casing grooves 342 may be closer to an edge 347 of the second portion 328 of the VGD ring casing 304 than a second end 348 of the casing groove 342. The VGD ring casing 304 may include three casing grooves 342 disposed at equal distance from one another on the second side wall 332 of the gap 318 (e.g., of the second portion 328 of the VGD ring casing 304). For example, each casing groove 342 may be positioned at 120 degrees about a circle formed by the second portion 328 of the VGD ring casing 304.

[0057] With the foregoing in mind, FIG. 8 is a perspective view of an embodiment of the VGD ring 204 of the VGD ring actuator assembly 206 (e.g., the VGD ring assembly 202) of the centrifugal compressor 32 of the HVAC&R system 10. In particular, the VGD ring 204 illustrated in FIG. 8 may be configured to be installed within the gap 318 of the VGD ring casing 304 illustrated in FIG. 7. In addition, the VGD ring 204 may include an inner side wall 350, an outer side wall 352, and a first face 354. The inner side wall 350 may be smaller in diameter than the outer side wall 352, and the inner side wall 350 may be configured to face towards a center 358 of the VGD ring 204, while the outer side wall 352 may be configured to face away from the center 358. When installed within the VGD ring casing 304, the inner side wall 350 may face the second side wall 332 of the gap 318, while the outer side wall 352 may face the first side wall 330 of the gap 318. Furthermore, the VGD ring 204 may include one or more ring grooves 356 positioned within the inner side wall 350 of the VGD ring 204. Each of the one or more ring grooves 356 may be paired with (e.g., associated with) a respective casing groove 342 of the VGD ring casing 304. In addition, the one or more rolling elements 344 may be positioned within the ring grooves 356 of the VGD ring 204 as well as the casing grooves 342.

[0058] Each ring groove 356, the associated casing groove 342, and/or the respective rolling elements 344 disposed therein may facilitate coupling between the VGD ring casing 304 and the VGD ring 204. In particular, for each rolling element 344, a first portion of the rolling element 344 may be within a respective casing groove 342, while a second portion of the rolling element 344 may be within a respective ring groove 356 opposite the respective casing groove 342. In this way, the VGD ring 204 may be rollingly engaged (e.g., coupled) to the VGD ring casing 304. In addition, each rolling element 344 may rotate (e.g., roll) within the respective ring groove 356 and change position within the ring groove 356. In other words, the ring groove 356 (e.g., the VGD ring 204) may rotate while each of the rollingly engaged rolling elements 344 may maintain a fixed position, with respect to the axis 106. Moreover, each of the one or more ring grooves 356 may extend at an angle with respect to the axis 106. In particular, a first end 360 of a ring groove 356 of the one or more ring grooves 356 may be closer to an inner edge 364 of the inner side wall 350 of the VGD ring 204 than a second end 362 of the ring groove 356. The VGD ring 204 may include three ring grooves 356 disposed at equal distance from one another within the inner side wall 350 of the VGD ring 204, each ring groove 356 corresponding with a respective casing groove 342. For example, each ring groove 356 may be positioned at 120 degrees about a circle formed by the inner side wall 350 of the VGD ring 204. As discussed herein, each of the angled grooves (e.g., the paired casing grooves 342 and ring grooves 356) along with the rolling elements 344 enable rotational movement and/or a force causing rotational movement of the VGD ring 204 to be converted to translational movement of the VGD ring 204 in the first direction 210 or the second direction 212. In particular, a force applied to the VGD ring 204 to cause rotation of the VGD ring 204 in the first rotational direction 314 may cause the VGD ring 204 to simultaneously translate in the second direction 212, while a force applied to the VGD ring 204 to cause rotation of the VGD ring 204 in the second rotational direction 316 may cause the VGD ring 204 to simultaneously translate in the first direction 210. Thus, the coupling of the VGD ring 204 to the VGD ring casing 304 facilitates extension and retraction of the VGD ring 204 into and out of the diffuser inlet of the compressor 32 dependent on a direction of a forces and the resulting rotational movement of the VGD ring 204 in the first rotational direction 314 or the second rotational direction 316, about the axis 106. In other embodiments, different translational guides may be employed (e.g., one or more extensions from the VGD ring 204 configured to travel through a respective casing groove 342, or vice versa). For example, the VGD ring 204 and the VGD ring casing 304 may be threaded and the threads may be represented by the grooves 342, 356.

[0059] FIG. 9 is a cross-sectional perspective view of an embodiment of a VGD ring actuator assembly 206 of the centrifugal compressor 32 of the HVAC&R system 10. In particular, as discussed herein, a version of the VGD ring assembly 202 may be positioned at each diffuser inlet of each diffuser passage (e.g., each stage) of the compressor 32. Furthermore, each VGD ring assembly 202 may include a respective VGD ring actuator assembly 206 coupled to a respective VGD ring 204. Each VGD ring actuator assembly 206 may include a VGD ring casing 304 configured to enclose and/or house at least a portion of the VGD ring 204, and a VGD ring actuator 306 configured to couple to and actuate the VGD ring 204. In particular, the VGD ring actuator 306 may be a mechanical VGD ring actuator and include an actuator 400 coupled to an arm 402 (e.g., mechanical arm). In some embodiments, the actuator 400 may be installed on an external casing (e.g., pump casing, volute casing) of the compressor 32, and the arm 402 may extend from the actuator 400 and through the casing (e.g., pump casing, volute casing) and a portion of the VGD ring casing 304 to couple to the VGD ring 204. In this way, the actuator 400 may be outside of (e.g., external to) the one or more compressor stages 104 of the compressor 32, and thus facilitate a more compact design (e.g., compact stages) of the compressor 32. Furthermore, the arm 402 may be controllably actuated by the actuator 400 and configured to apply a force to the VGD ring 204. In particular, the arm 402 may be coupled to the VGD ring 204 at a first end 404 of the arm 402 and coupled to the actuator 400 at a second end 406 of the arm 402, the second end 406 opposite the first end 404. Moreover, the arm 402 may extend through a channel 410 (also illustrated in FIG. 7) formed within the first portion 326 of the VGD ring casing 304 to couple to the outer side wall 352 of the VGD ring 204. During operation, the actuator 400 may cause the arm to translate within the channel 410 in a third direction 412 or a fourth direction 414. In some embodiments, the movement of the arm 402 in the third direction 412 may cause the VGD ring 204 coupled to the arm 402 to rotate in the second rotational direction 316 about the axis 106. On the other hand, the movement of the arm 402 in the fourth direction 414 may cause the VGD ring 204 coupled to the arm 402 to rotate in the first rotational direction 314 about the axis 106. Furthermore, as discussed herein, the rotational movement of the VGD ring 204 may be converted to translational movement of the VGD ring 204 in the first and/or second directions 210, 212. Therefore, the actuator 400 may controllably extend the VGD ring into the respective diffuser inlet of the compressor 32, so as to decrease a volume of the diffuser inlet, and/or retract the VGD ring 204 out of the respective diffuser inlet of the compressor 32, so as to increase the volume of the diffuser inlet. As discussed herein, the one or more actuators 400 (e.g., of each VGD ring assembly 202) may be communicatively coupled to the control system 222. In particular, the control system 222 may be configured to instruct the one or more actuators 400 to cause rotation of the respective VGD ring 204 and thus cause translation of the respective VGD ring 204 relative to the axis 106. [0060] FIG. 10 is a cross-sectional perspective view of an embodiment of a VGD ring actuator assembly 206 of the centrifugal compressor 32 of the HVAC&R system 10. In particular, as discussed herein, the VGD ring assembly 202 may be positioned at each diffuser inlet of each diffuser passage (e.g., each stage) of the compressor 32. Furthermore, each VGD ring assembly 202 may include a respective VGD ring actuator assembly 206 coupled to a respective VGD ring 204. Each VGD ring actuator assembly 206 may include a VGD ring casing 304 configured to enclose and/or house at least a portion of the VGD ring 204, and a VGD ring actuator 306 configured to couple to and actuate the VGD ring 204. In some embodiments, the VGD ring actuator 306 may be a hydraulic actuator (e.g., hydraulic circuit) configured to actuate the VGD ring 204 by controlling placement of incompressible fluid (e.g., hydraulic oil). In particular, in some embodiments, the VGD ring casing 304 may include one or more fluid channels 420 extending through the first portion 326 of the VGD ring casing 304. The one or more fluid channels 420 may be fluidly coupled to the VGD ring actuator 306. Furthermore, VGD ring actuator 306 may be configured to control an amount (e.g., volume) of incompressible fluid within the one or more fluid channels 420. In addition, the VGD ring 204 may include one or more fluid grooves 422 each fluidly coupled to a respective fluid channel 420. FIG. 11 is a perspective view of an embodiment of a VGD ring 204 including the one or more fluid grooves 422. As illustrated, the one or more fluid grooves 422 may be positioned within the outer side wall 352 of the VGD ring 204. Moreover, the one or more fluid grooves 422 may extend at an angle with respect to the axis 106. In particular, a respective first end 424 of each of the one or more fluid grooves 422 may be closer to an outer edge 426 of the VGD ring 204 than a respective second end 428 of each of the one or more fluid grooves 422. In some embodiments, the VGD ring 204 may include two fluid grooves 422 each fluidly coupled to a respective fluid channel. In addition, a portion of a first fluid groove 430, including the respective second end 428, may overlap (with respect to the axis 106) with a portion of a second fluid groove 432, including the respective first end 424. The first and second fluid grooves 430, 432 substantially equal in length and extending at substantially the same angle with respect to the axis 106. [0061] As discussed above, the VGD ring actuator 306 may be configured to control an amount of incompressible fluid within the one or more fluid channels 420, and thus control an amount of the incompressible fluid with the one or more fluid grooves 422 of the VGD ring 204. In particular, the VGD ring actuator 306 may adjust an amount of the incompressible fluid within the one or more fluid channels 420, which then may produce a rotational force applied to the VGD ring 204 to cause the VGD ring 204 to rotate in the first and/or the second rotational directions 314, 316. Rotation of the VGD ring 204 in the first and/or the second rotational directions 314, 316 may be simultaneously converted into translational movement of the VGD ring 204 in the first and/or the second direction 210, 212. As discussed herein, the VGD ring actuator 306 may be installed and/or positioned in a space outside of the one or more compressor stages of the multistage centrifugal compressor, such as in and/or external to a pump casing (e.g., volute) of the multistage centrifugal compressor. In this way, the VGD regulation system 200 may be compact and/or positioned in an area that optimizes a length of the compressor shaft and/or maintain a relatively short shaft length, while efficiently regulating compressor capacity of the compressor 32.

[0062] Moreover, the compact VGD ring assemblies 202 of the centrifugal compressor 32 of the present disclosure produce a compact VGD regulation system 200 for the centrifugal compressor 32 that enables independent operation (e.g., control) of the VGD actuator ring assemblies to improve efficiency and performance of the centrifugal compressor 32, even at partial load conditions, by reducing instability or inconsistency of flow within the 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 each VGD ring actuator assembly to independently operate and actuate a respective VGD ring associated with a respective diffuser passage of the centrifugal compressor 32. In particular, each VGD ring actuator assembly controls 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 a second, a third, a fourth, etc. compressor stages, 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 centrifugal compressor 32 while also maintaining a relatively compact (e.g., substantially short) overall shaft length (e.g., axial length) of the centrifugal compressor 32 by positioning (e.g., installing) the VGD ring actuators external to the one or more compressor stages, such as in and/or external to a pump casing (e.g., volute) of the multistage centrifugal compressor. In this way, the VGD ring actuators may be positioned in an area that optimizes a length of the compressor shaft and/or maintains a relatively short shaft length. 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.).

[0063] 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. [0064] 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 diffuser passage comprising a diffuser inlet; and a variable geometry diffuser (VGD) regulation system, comprising: a VGD housing; a VGD ring disposed at the diffuser inlet, wherein at least a portion of the VGD ring is within the VGD housing; and a VGD ring actuator coupled to VGD ring, wherein the VGD ring actuator is configured to actuate the VGD ring between a retracted position and an extended position relative to the VGD housing.

2. The HVAC&R system of claim 1, wherein the VGD housing comprises a gap formed from a first portion of the VGD housing being offset from a second portion of the VGD housing, wherein at least a portion of the VGD ring is disposed within the gap.

3. The HVAC&R system of claim 2, wherein the first portion of the VGD housing comprises one or more channels and the VGD ring actuator is configured to at least partially extend through the first portion of the VGD housing via the one or more channels to couple to the VGD ring.

4. The HVAC&R system of claim 3, wherein the VGD ring actuator is a hydraulic VGD ring actuator configured to fluidly couple to the VGD ring via the one or more channels within the first portion of the VGD housing.

5. The HVAC&R system of claim 4, wherein the VGD ring comprises one or more fluid grooves coupled to the VGD ring actuator via a hydraulic circuit, and wherein the VGD ring actuator is configured to control a volume of incompressible fluid within the one or more fluid grooves to cause rotation of the VGD ring.

6. The HVAC&R system of claim 2, wherein the VGD ring actuator is a mechanical VGD ring actuator and comprises a mechanical arm configured to extend through a passage in the first portion of the VGD housing to couple to the VGD ring.

7. The HVAC&R system of claim 2, wherein the second portion comprises one or more grooves configured to facilitate coupling of the second portion with the VGD ring via one or more ring grooves of the VGD ring.

8. The HVAC&R system of claim 7, wherein the VGD ring actuator is configured to apply a rotational force to the VGD ring, and wherein the one or more grooves and the one or more ring grooves are configured to convert the rotational force to a translational force causing the VGD ring to extend into or retract out of the diffuser inlet.

9. The HVAC&R system of claim 1, wherein the VGD housing and the VGD ring are installed within a compressor stage of the compressor and a portion of the VGD ring actuator is installed on an exterior surface of the compressor.

10. The HVAC&R system of claim 1, wherein a first volume of the diffuser inlet when the VGD ring is in the retracted position is greater than a second volume of the diffuser inlet when the VGD ring is in the extended position.

11. A variable geometry diffuser (VGD) regulation system for a compressor of a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system, comprising: a VGD ring casing positioned at a diffuser passage of the compressor; a VGD ring coupled to the VGD ring casing and disposed adjacent to a diffuser inlet of the diffuser passage, wherein at least a portion of the VGD ring is within the VGD ring casing; and a VGD ring actuator coupled to the VGD ring, wherein the VGD ring actuator is configured to extend through at least a portion of the VGD ring casing to couple to the VGD ring.

12. The VGD system of claim 11, wherein the VGD ring actuator is configured to actuate the VGD ring between a retracted position and an extended position, and wherein the retracted position is configured to cause a first volume of the diffuser inlet to be greater than a second volume of the diffuser inlet caused when the VGD ring is in the extended position.

13. The VGD system of claim 12, wherein the VGD casing comprises a first portion of the VGD casing concentrically encompassing a second portion of the VGD casing, wherein the first portion of the VGD casing is offset from the second portion of the VGD casing and at least a portion of the VGD ring is positioned between the first portion of the VGD casing and the second portion of the VGD casing.

14. The VGD system of claim 13, wherein the first portion of the VGD casing comprises one or more channels and the VGD ring actuator is configured to extend partially through the first portion of the VGD casing via the one or more channels to couple to the VGD ring.

15. The VGD system of claim 14, wherein the VGD ring actuator is a hydraulic VGD ring actuator configured to fluidly couple to the VGD ring via the one or more channels, and wherein the VGD ring comprises one or more fluid grooves fluidly coupled to the one or more channels via a hydraulic circuit, and wherein the hydraulic VGD ring actuator is configured to control a volume of incompressible fluid within the one or more fluid grooves to cause actuation of the VGD ring between the retracted position and the extended position.

16. The VGD system of claim 14, wherein the VGD ring actuator is a mechanical VGD ring actuator comprising a mechanical arm configured to extend through a passage in the first portion of the VGD casing to couple to the VGD ring, and wherein the mechanical VGD ring actuator is configured to apply a force to the VGD ring via the mechanical arm to cause actuation of the VGD ring between the retracted position and the extended position.

17. The VGD system of claim 11, wherein the VGD ring casing is a first VGD ring casing positioned at a first diffuser passage of the compressor, the VGD ring is a first VGD ring disposed adjacent to a first diffuser inlet of the first diffuser passage, and the VGD ring actuator is a first VGD ring actuator, and wherein the VGD system comprises: a second VGD ring casing positioned at a second diffuser passage of the compressor; a second VGD ring coupled to the second VGD ring casing and disposed adjacent to a second diffuser inlet of the second diffuser passage, wherein at least a portion of the second VGD ring is within the second VGD ring casing; a second VGD ring actuator coupled to the second VGD ring, wherein the second VGD ring actuator is configured to extend through at least a portion of the second VGD ring casing to couple to the second VGD ring, and wherein the first VGD ring actuator and the second VGD ring actuator are communicatively coupled to a controller configured to cause actuation of the first VGD ring independent of actuation of the second VGD ring.

18. 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 VGD ring housing configured to be positioned at a diffuser passage of the compressor, wherein the VGD ring housing comprises a gap formed from a first portion of the VGD housing being offset from a second portion of the VGD housing; a VGD ring coupled to the VGD ring housing and configured to be disposed adjacent to a diffuser inlet of the diffuser passage, wherein at least a portion of the VGD ring is within the gap; and a VGD ring actuator assembly coupled to the VGD ring, wherein the VGD ring actuator assembly extends through at least a portion of the VGD ring housing to couple to the VGD ring; and a controller communicatively coupled to the VGD regulation system and configured to control actuation of the VGD ring between a retracted position and an extended position relative to the VGD ring housing, wherein the extended position is associated with at least a portion of the VGD ring positioned exterior to the VGD ring housing.

19. The HVAC&R system of claim 18, wherein the VGD ring actuator assembly is configured to fluidly couple to one or more fluid grooves of the VGD ring via a hydraulic circuit, and wherein the controller is configured to cause adjustment of a volume of incompressible fluid within the one or more fluid grooves to control actuation of the VGD ring between the retracted position and the extended position.

20. The HVAC&R system of claim 18, wherein the VGD ring actuator assembly comprises a mechanical arm configured to extend through a passage in the VGD housing to couple to the VGD ring, and wherein the controller is configured to cause application of a force to the VGD ring via the mechanical arm to control actuation of the VGD ring between the retracted position and the extended position.