Compressor system for heating, ventilation, air conditioning and refrigeration systems

Abstract

A heating, ventilation, air conditioning and / or refrigeration system (10) configured to circulate a working fluid therethrough includes an economizer system (116) and a compressor system (106). A first economizer (118) of the economizer system (116) is configured to reduce a first pressure of the working fluid to provide a first vapor working fluid flow (124), and a second economizer (122) of the economizer system (116) is configured to reduce a second pressure of the working fluid in the second economizer (122) to provide a second vapor working fluid flow (128). A first compressor stage (110) of the compressor system (100) is configured to receive a second vapor working fluid flow (128) from a second economizer (122) via a second inlet (132), and to receive an additional working fluid flow (113) separated from the second vapor working fluid flow (128) via a first inlet (130). A second compressor stage (112) of the compressor system (106) is configured to receive the first vapor working fluid flow (124) from the first economizer (118) via a third inlet (136).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 390,004, filed on July 18, 2022, entitled “COMPRESSOR SYSTEM FOR HEATING, VENTILATION, AIR CONDITIONING & REFRIGERATION SYSTEM,” which is hereby incorporated by reference in its entirety for all purposes. Background Art

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

[0004] A freezer system or vapor compression system utilizes a working fluid (e.g., a refrigerant) that changes the phase between vapor, liquid, and a combination thereof in response to different temperatures and pressures within the components exposed to the freezer system. The freezer 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 a conditioning device and / or a regulated environment served by the freezer system. In some embodiments, the freezer system may include an economizer configured to improve the efficiency of the freezer system. For example, a first heat exchanger (e.g., a condenser) may cool the working fluid and direct the cooled working fluid to the economizer, which may separate the working fluid into a liquid-phase working fluid and a gas-phase working fluid. The economizer may direct the liquid-phase working fluid to a second heat exchanger (e.g., an evaporator), which is configured to place the working fluid in a heat exchange relationship with the cooling fluid. The economizer may direct the gas-phase working fluid to a compressor system for pressurization. Unfortunately, existing freezer systems including economizers may be costly and / or may operate inefficiently. Summary of the invention

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

[0006] In one embodiment, a heating, ventilation, air conditioning and / or refrigeration system configured to circulate a working fluid therethrough includes: an economizer system and a compressor system. A first economizer of the economizer system is configured to reduce a first pressure of the working fluid to provide a first vapor working fluid flow, and a second economizer of the economizer system is configured to reduce a second pressure of the working fluid in the second economizer to provide a second vapor working fluid flow. A first compressor stage of the compressor system is configured to receive a second vapor working fluid flow from the second economizer via a second inlet, and to receive an additional working fluid flow separated from the second vapor working fluid flow via the first inlet. A second compressor stage of the compressor system is configured to receive a first vapor working fluid flow from the first economizer via a third inlet.

[0007] In another embodiment, a vapor compression system for a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system configured to circulate a working fluid therethrough includes: a first economizer configured to reduce a first pressure of the working fluid in the first economizer to provide a first vapor working fluid stream; a second economizer configured to reduce a second pressure of the working fluid in the second economizer to provide a second vapor working fluid stream; an evaporator configured to place the working fluid in the evaporator in heat exchange relationship with a cooling fluid to provide a third vapor working fluid stream; and a compressor system. The compressor system includes: a first compressor stage including a first inlet and a second inlet, wherein the first inlet is configured to receive the first working fluid stream and the second inlet is configured to receive the second working fluid stream separated from the first working fluid stream; and a second compressor stage including a third inlet configured to receive the third working fluid stream, wherein each of the first working fluid stream, the second working fluid stream, and the third working fluid stream includes a different one of the first vapor working fluid stream, the second vapor working fluid stream, and the third vapor working fluid stream.

[0008] In another embodiment, a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system configured to circulate a working fluid therethrough includes: an economizer system including one or more economizers configured to reduce a pressure of a working fluid in the one or more economizers to provide one or more vapor working fluid streams; and a compressor system. The compressor system includes: a first compressor stage including a first inlet and a second inlet, wherein the first compressor stage is configured to receive a first vapor working fluid stream of the one or more vapor working fluid streams via the second inlet, and the first compressor stage is configured to receive an additional working fluid stream separated from the first vapor working fluid stream via the first inlet; and a second compressor stage including a third inlet, wherein the second compressor stage is configured to receive a second vapor working fluid stream of the one or more vapor working fluid streams via the third inlet.

[0009] Various improvements of the above-mentioned features associated with various aspects of the present disclosure may exist. Additional features may also be incorporated into these different aspects. These improvements and additional features may exist alone or in any combination. For example, various features associated with one or more of the illustrated embodiments discussed below may be incorporated into any of the above-mentioned aspects of the present disclosure alone or in any combination. The brief overview presented above is intended only to familiarize the reader with certain aspects and contexts of the embodiments of the present disclosure, without limiting the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Various aspects of the present disclosure may be better understood after reading the following detailed description and referring to the drawings, in which:

[0011] Figure 1 is a perspective view of a building utilizing an embodiment of a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system in a commercial environment according to an aspect of the present disclosure;

[0012] Figure 2 is a perspective view of an embodiment of a vapor compression system according to an aspect of the present disclosure;

[0013] Figure 3 According to one aspect of the present disclosure Figure 2 A schematic diagram of an embodiment of a vapor compression system;

[0014] Figure 4 According to one aspect of the present disclosure Figure 2 A schematic diagram of an embodiment of a vapor compression system;

[0015] Figure 5 is a schematic diagram of an embodiment of a vapor compression system according to an aspect of the present disclosure, the vapor compression system including an economizer system and a compressor system having a compressor configured to receive a separated stream of working fluid;

[0016] Figure 6 is a partial cross-sectional side view of an embodiment of a compressor configured to receive a separated stream of working fluid according to an aspect of the present disclosure;

[0017] Figure 7 is a schematic diagram of an embodiment of a compressor system according to an aspect of the present disclosure, the compressor system including a compressor configured to receive a separated stream of working fluid;

[0018] Figure 8 is a schematic diagram of an embodiment of a compressor system according to an aspect of the present disclosure, the compressor system including a compressor configured to receive a separated stream of working fluid;

[0019] Fig. 9is a schematic diagram of an embodiment of a compressor system according to an aspect of the present disclosure, the compressor system including a compressor configured to receive a separated stream of working fluid;

[0020] Fig.10 is a schematic diagram of an embodiment of a vapor compression system according to an aspect of the present disclosure, the vapor compression system including an economizer system and a compressor system having a compressor configured to receive a separated stream of working fluid;

[0021] Fig.11 is a schematic diagram of an embodiment of a vapor compression system according to an aspect of the present disclosure, the vapor compression system including an economizer system and a compressor system having a compressor configured to receive a separated stream of working fluid;

[0022] Fig.12 is a schematic diagram of an embodiment of a compressor system according to an aspect of the present disclosure, the compressor system including a compressor configured to receive a separated stream of working fluid;

[0023] Fig.13 is a schematic diagram of an embodiment of a vapor compression system according to an aspect of the present disclosure, the vapor compression system including an economizer system and a compressor system having a compressor configured to receive a separated stream of working fluid; and

[0024] Fig.14 is a schematic diagram of an embodiment of a vapor compression system according to an aspect of the present disclosure, the vapor compression system including an economizer system and a compressor system having a compressor configured to receive a separated stream of working fluid. DETAILED DESCRIPTION

[0025] One or more specific embodiments will be described below. In order to provide a concise description of these embodiments, not all features of the actual implementation are described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the specific goals of the developer, such as consistency with system-related and enterprise-related constraints, which may vary from one implementation to another. In addition, it should be understood that such development work may be complex and time-consuming, but will be a routine task of design, production and manufacturing for ordinary technicians who benefit from this disclosure.

[0026] When introducing elements of various embodiments of the present disclosure, the articles "a," "an," and "the" are intended to indicate the presence of one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements in addition to the listed elements. Additionally, it should be understood that references to "one embodiment" or "an embodiment" of the present disclosure are not intended to be interpreted as excluding the presence of additional embodiments that are further incorporated into the recited features.

[0027] As used herein, the terms "approximately," "substantially," "substantially," and the like are intended to convey that the value of the property being described may be within a relatively small range of that property value, as understood by one skilled in the art. For example, when a property value is described as being "approximately" equal to (or, for example, "substantially similar to") a given value, this is intended to convey that the property value may be within + / -5%, within + / -4%, within + / -3%, within + / -2%, within + / -1%, or even closer of the given value. Similarly, when a given feature is described as being "substantially parallel" to another feature, "substantially perpendicular" to another feature, and the like, this is intended to convey that the given feature is within + / -5%, within + / -4%, within + / -3%, within + / -2%, within + / -1%, or even closer of the described property, such as being parallel to another feature, being perpendicular to another feature, and the like. Mathematical terms, such as "parallel" and "perpendicular," should not be strictly interpreted in a strict mathematical sense, but rather should be interpreted as one of ordinary skill in the art would interpret such terms. For example, one of ordinary skill in the art will understand that two lines that are generally parallel to each other are largely parallel, but may have slight deviations from being completely parallel.

[0028] Embodiments of the present disclosure relate to a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system having a vapor compression system (e.g., a vapor compression loop). The vapor compression system may include a compressor system configured to 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 the pressure of the working fluid and further cool the working fluid. The cooled working fluid may be directed from the expansion device to an evaporator, which may place the working fluid in a heat exchange relationship with a cooling fluid to cool the cooling fluid. The compressor system may then receive the working fluid from the evaporator for pressurization, thereby restarting the vapor compression cycle.

[0029] In some embodiments, the vapor compression system may include an economizer system configured to receive a working fluid from a condenser. The economizer may include one or more economizers (e.g., economizer stages) configured to separate the working fluid into a liquid working fluid and a vapor working fluid. The economizer may guide the liquid working fluid to the evaporator and guide the vapor working fluid toward the compressor system for pressurization. In order to improve the performance (e.g., efficiency) of the vapor compression system, the compressor system may include a plurality of compressors or compressor stages, such as separate compressor impellers, which may receive corresponding vapor working fluid flows guided by the economizer. As described herein, a single compressor stage receives a vapor working fluid flow and pressurizes the vapor working fluid flow to a higher pressure to provide a pressurized vapor working fluid flow. As an example, each compressor stage may receive a vapor working fluid flow from one of the economizers, and increase the pressure of the vapor working fluid flow to a specific pressure that promotes the flow of the vapor working fluid flow through the vapor compression system. For example, a compressor stage may increase the pressure of a vapor working fluid stream toward the pressure of an additional working fluid stream (e.g., a working fluid stream pressurized by a different compressor or compressor stage) to enable both the vapor working fluid stream and the additional working fluid stream to flow as desired (e.g., a combined flow) to another component, rather than causing, for example, undesired backflow of the working fluid to the compressor stage, uneven mixing between the working fluid streams, or other flow interruptions that impede flow to other components. Such flow interruptions may be caused by excessive pressure differentials between the vapor working fluid stream and the additional working fluid stream, and the flow interruptions may reduce the effective flow of the working fluid to another component and through the vapor compression system. However, increasing the number of compressor stages implemented in a vapor compression system may increase the cost and / or complexity associated with the manufacture, installation, and / or operation of the vapor compression system.

[0030] It is therefore now recognized that there is a need for improvements in HVAC&R systems having economizer systems. Accordingly, embodiments of the present disclosure are directed to a compressor system comprising a single compressor stage that can receive multiple separate working fluid streams. For example, a compressor stage may include a first inlet configured to receive a first working fluid stream (e.g., from an evaporator) and a second inlet configured to receive a second working fluid stream (e.g., from an economizer). The compressor stage may both pressurize the working fluid stream and discharge the pressurized working fluid stream, such as to a condenser or to another compressor stage. For example, such a compressor stage may be a single-stage energy-saving compressor that is configured to receive a working fluid stream via a first inlet and receive an additional working fluid stream from an economizer via a second inlet, and pressurize the two working fluid streams to approximately the same pressure. In fact, a single-stage energy-saving compressor may have multiple inlets configured to receive corresponding working fluid streams that may be at different suction pressures, and the single-stage energy-saving compressor may have a single impeller configured to pressurize each working fluid stream to a common, increased pressure. Such compressor stages can operate more efficiently to pressurize the working fluid stream than a compressor stage having a single inlet configured to receive the working fluid stream (e.g., a compressor stage dedicated to pressurizing a vapor working fluid stream from a single economizer in an economizer). That is, a compressor stage having multiple inlets can be configured to pressurize relatively more working fluid streams, such as to a common pressure. Thus, a compressor system can utilize a limited number of compressor stages to pressurize a vapor working fluid stream (e.g., a separate vapor working fluid stream) from an economizer system (such as an economizer system having multiple economizers or economizer stages). Thus, the manufacture, installation, and / or operation of a vapor compression system can be improved.

[0031] Now turning to the diagram, Figure 11 is a perspective view of an embodiment of an environment for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system 10 in a building 12 for a typical commercial environment. The HVAC&R system 10 may include a vapor compression system 14 (e.g., a chiller, a vapor compression loop) that supplies a cooling liquid that may be used to cool the building 12. The HVAC&R system 10 may also include a boiler 16 for supplying warm liquid to heat the building 12 and an air distribution system that circulates air through the building 12. The air distribution system may also include 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 via ducts 24. Depending on the operating mode of the HVAC&R system 10, the heat exchanger in the air handler 22 may receive heated liquid from the boiler 16 or cooled liquid from the vapor compression system 14. The HVAC&R system 10 is shown with separate air handlers on each floor of the building 12, but in other embodiments, the HVAC&R system 10 may include air handlers 22 and / or other components that may be shared between floors.

[0032] Figure 2 and Figure 3 is an embodiment of a vapor compression system 14 that may be used in the HVAC&R system 10. The vapor compression system 14 may circulate a refrigerant through a circuit beginning with a compressor 32. The circuit may also include a condenser 34, an expansion valve or device 36, and a liquid chiller or evaporator 38. The vapor compression system 14 may further include a control panel 40 having an analog-to-digital (A / D) converter 42, a microprocessor 44, a non-volatile memory 46, and / or an interface board 48.

[0033] Some examples of fluids that can be used as refrigerants in the vapor compression system 14 are hydrofluorocarbon (HFC) based refrigerants, such as R-410A, R-407, R-134a, R-1234ze, R1233zd, hydrofluoroolefins (HFO), "natural" refrigerants such as ammonia (NH3), R-717, carbon dioxide (CO2), R-744 or hydrocarbon based refrigerants, water vapor or any other suitable refrigerant. In some embodiments, the vapor compression system 14 can be configured to effectively utilize a refrigerant having a standard boiling point of about 19 degrees Celsius (66 degrees Fahrenheit) at one atmosphere of pressure, which is also referred to as a low pressure refrigerant relative to a medium pressure refrigerant such as R-134a. As used herein, "standard boiling point" can refer to a boiling point temperature measured at one atmosphere of pressure.

[0034] In some embodiments, the vapor compression system 14 may use one or more of a variable speed drive (VSD) 52, a motor 50, a compressor 32, a condenser 34, an expansion valve or device 36, and / or an evaporator 38. The motor 50 may drive the compressor 32 and may be powered by the variable speed drive (VSD) 52. The VSD 52 receives AC power having a specific fixed line voltage and a fixed line frequency from an alternating current (AC) power source and provides power having a variable voltage and frequency to the motor 50. In other embodiments, the motor 50 may be powered directly by an AC or direct current (DC) power source. The motor 50 may include any type of motor that may be powered by a VSD or directly by an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.

[0035] The compressor 32 compresses the 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. The refrigerant vapor delivered to the condenser 34 by the compressor 32 may transfer heat to a cooling fluid (e.g., water or air) in the condenser 34. As a result of the heat transfer with the cooling fluid, the refrigerant vapor may condense into a refrigerant liquid in the condenser 34. The liquid refrigerant from the condenser 34 may flow to the evaporator 38 through the expansion device 36. In Figure 3 In the illustrated embodiment, the condenser 34 is water cooled and includes a tube bundle 54 connected to a cooling tower 56 that supplies cooling fluid to the condenser 34 .

[0036] 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 liquid refrigerant to refrigerant vapor. Figure 3 As shown in the illustrated embodiment of FIG. 1 , 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 through the return line 60R and leaves the evaporator 38 through the supply line 60S. The evaporator 38 may reduce the temperature of the cooling fluid in the tube bundle 58 by heat transfer with the refrigerant. The tube bundle 58 in the evaporator 38 may include multiple tubes and / or multiple tube bundles. In any case, the vapor refrigerant leaves the evaporator 38 and returns to the compressor 32 through the suction line to complete the cycle.

[0037] Figure 4is a schematic diagram of vapor compression system 14 in which intermediate loop 64 is incorporated between condenser 34 and expansion device 36. Intermediate loop 64 may have an inlet line 68 that is directly fluidly connected to condenser 34. In other embodiments, inlet line 68 may be indirectly fluidly coupled to condenser 34. Figure 4 As shown in the illustrated embodiment of FIG. 1 , the inlet line 68 includes a first expansion device 66 positioned upstream of an intermediate vessel 70 that is incorporated into the vapor compression system 14 described above to provide efficient operation. In some embodiments, the intermediate vessel 70 may be a flash tank (e.g., a flash intercooler, an economizer). In other embodiments, the intermediate vessel 70 may be configured as a heat exchanger or a "surface economizer." Figure 4 In the illustrated embodiment of , the intermediate container 70 functions as a flash tank, and the first expansion device 66 is configured to reduce (e.g., expand) the pressure of the liquid refrigerant received from the condenser 34. During the expansion process, a portion of the liquid may evaporate, and thus the intermediate container 70 may be used to separate the vapor from the liquid received from the first expansion device 66.

[0038] In addition, the intermediate container 70 can provide further expansion of the liquid refrigerant due to the pressure drop experienced by the liquid refrigerant when entering the intermediate container 70 (e.g., due to the rapid increase in volume experienced when entering the intermediate container 70). The vapor in the intermediate container 70 can be sucked in by the compressor 32 through the suction line 74 of the compressor 32. For example, the compressor 32 can include a single compressor stage that is configured to receive vapor from the evaporator 38 and vapor from the intermediate container 70 and pressurize it to a specific pressure. Due to expansion in the expansion device 66 and / or the intermediate container 70, the enthalpy of the liquid collected in the intermediate container 70 can be lower than the enthalpy of the liquid refrigerant leaving the condenser 34. The liquid from the intermediate container 70 can then flow through the second expansion device 36 in the pipeline 72 to the evaporator 38.

[0039] It should be understood that any of the features described herein can be combined with the vapor compression system 14 or any other suitable HVAC&R system. For example, the present technology can be combined with any HVAC&R system having an economizer (such as the intermediate container 70) and a compressor (such as the compressor 32). The following discussion describes the present technology in combination with an embodiment of the compressor 32 configured as a single-stage compressor. However, it should be noted that the systems and methods described herein can be combined with other embodiments of the compressor 32 (e.g., a multi-stage compressor) and the HVAC&R system 10.

[0040] The present disclosure is directed to an HVAC&R system having a compressor system including a compressor configured to receive and pressurize a separated working fluid stream. For example, the compressor may include a first inlet configured to receive a first working fluid stream, such as from an evaporator and / or from another compressor. The compressor may include a second inlet configured to receive a second working fluid stream, such as from an economizer (e.g., an intermediate container 70). The compressor may pressurize the first and second working fluid streams and discharge the pressurized working fluid stream (e.g., discharge to a condenser, discharge to another compressor). In this way, a single compressor of the compressor system may be utilized to pressurize multiple separated working fluid streams. Therefore, the compressor system may include a smaller number of compressors compared to a compressor system having a compressor embodiment configured to receive and pressurize a single working fluid stream. Therefore, the compressor system may pressurize separated working fluid streams (including working fluid streams received from economizers) at a reduced cost and / or complexity associated with the manufacture, installation, and / or operation of the HVAC&R system.

[0041] Considering the foregoing, Figure 5 1 is a schematic diagram of an embodiment of a vapor compression system or circuit 100 (e.g., of an HVAC&R system) configured to circulate a working fluid. The vapor compression system 100 may include a condenser 102 (e.g., condenser 34) configured to cool the working fluid and an evaporator 104 (e.g., evaporator 38) configured to place the working fluid in heat exchange relationship with a cooling fluid to absorb heat from the cooling fluid. The vapor compression system 100 may also include a compressor system 106 configured to pressurize the working fluid. For example, the compressor system 106 may be configured to receive the working fluid from the evaporator 104, pressurize the working fluid, and direct the pressurized working fluid to the condenser 102.

[0042] In the illustrated embodiment, the compressor system 106 includes a plurality of compressors, such as compressor impellers and / or stages, arranged in a series flow arrangement (e.g., a plurality of single-stage compressors arranged in series) relative to a refrigerant flow through the compressor system 106. For example, the compressor system 106 may include a first compressor or compressor stage 110 (e.g., a first single-stage compressor configured to pressurize one or more vapor streams to a common, increased pressure) and a second compressor or compressor stage 112 (e.g., a second single-stage compressor configured to pressurize one or more vapor streams to a common, increased pressure). The first compressor 110 may receive a suction working fluid stream 113 from the evaporator 104, pressurize the suction working fluid stream 113, and discharge the pressurized suction working fluid stream 113 as a first pressurized working fluid stream 114 toward the second compressor 112. The second compressor 112 may receive the first pressurized working fluid stream 114, and further pressurize the first pressurized working fluid stream 114 for discharge toward the condenser 102 as a second pressurized working fluid stream 115. It should be noted that reference to an element (e.g., a system, component, etc.) that directs a fluid (e.g., a refrigerant in the gas or liquid phase) toward another element means that the element pressurizes, forces, directs (e.g., via pipes, valves, mechanical operations), etc., to deliver the fluid directly or indirectly to the other element.

[0043] The vapor compression system 100 may also include an economizer system 116 (e.g., an intermediate container system, a flash tank system) configured to receive refrigerant from the condenser 102. The economizer system 116 may include a plurality of economizers (e.g., economizer stages) configured to reduce the pressure of the working fluid to evaporate at least a portion of the working fluid, thereby separating the working fluid into a liquid working fluid and a vapor working fluid. For example, the economizer system 116 may include a first economizer 118, a second economizer 120, and a third economizer 122. The first economizer 118 may receive the working fluid from the condenser 102, reduce the pressure of the received working fluid to evaporate a portion of the received working fluid and separate the working fluid into a liquid working fluid and a vapor working fluid, and direct the liquid working fluid to the second economizer 120. The second economizer 120 may reduce the pressure of the liquid working fluid received from the first economizer 118 to evaporate a portion of the received working fluid, thereby separating the working fluid into a liquid working fluid and a vapor working fluid, and direct the liquid working fluid to the third economizer 122. The third economizer 122 may reduce the pressure of the liquid working fluid received from the second economizer 120 to evaporate a portion of the received working fluid, thereby separating the working fluid into liquid working fluid and vapor working fluid, and directing the liquid working fluid to the evaporator 104. According to the present embodiment, a different number of economizers may be utilized in such an arrangement.

[0044] Reducing the pressure of the refrigerant can further reduce the temperature of the refrigerant. Therefore, by further reducing the pressure of the refrigerant, the first economizer 118, the second economizer 120, and the third economizer 122 can increase the amount of cooling provided by the vapor compression system 100 to the cooling fluid, thereby increasing the efficiency of the vapor compression system 100. In certain embodiments, the economizer system 116 may include a single shell, housing, shell, or container, and each economizer 118, 120, 122 may include a separate chamber, compartment, or volume within the single shell. Additionally or alternatively, each economizer 118, 120, 122 may include a respective shell and shell that may be positioned adjacent to each other (e.g., coupled to each other) to form the economizer system 116.

[0045] It should be noted that the components of the vapor compression system 100 may be described as being positioned or arranged upstream or downstream of each other. As described herein, upstream and downstream may refer to the positioning of the components relative to the sequential flow of the refrigerant through the vapor compression system 100, such as from the compressor system 106 (e.g., from the first compressor 110 to the second compressor 112) to the condenser 102, to the economizer system 116, and to the evaporator 104 and / or back to the compressor system 106. For example, upstream may refer to a positioning in a direction opposite to the direction of the refrigerant flow through the vapor compression system 100 (e.g., a preceding position), and downstream may refer to a positioning in the direction of the refrigerant flow through the vapor compression system 100 (e.g., a traveling position).

[0046] Each compressor 110, 112 may be configured to receive a vapor working fluid from an economizer system 116. For example, the first economizer 118 and the second economizer 120 may discharge a first vapor working fluid stream 124 and a second vapor working fluid stream 126, respectively, to the second compressor 112 for pressurization. The third economizer 122 may discharge a third vapor working fluid stream 128 to the first compressor 110 for pressurization. The first compressor 110 may include a first inlet 130 configured to receive an intake working fluid stream 113 from the evaporator 104 and a second inlet 132 separated from the first inlet 130 and configured to receive the third vapor working fluid stream 128 from the third economizer 122. Thus, the first compressor 110 may receive the intake working fluid stream 113 and the third vapor working fluid stream 128 as separate working fluid streams for pressurization, and discharge as a first pressurized working fluid stream 114. The second compressor 112 may include a third inlet 134 configured to receive the first pressurized working fluid stream 114 from the first compressor 110 and the second vapor working fluid stream 126 from the second economizer 120. As an example, the second vapor working fluid stream 126 may be combined with the first pressurized working fluid stream 114 as a combined working fluid stream 135, and the combined working fluid stream 135 (e.g., the combined second vapor working fluid stream 126 and the first pressurized working fluid stream 114) may be directed to the second compressor 112 via the third inlet 134. The second compressor 112 may also include a fourth inlet 136 separated from the third inlet 134, the fourth inlet being configured to receive the first vapor working fluid stream 124 from the first economizer 118. Thus, the second compressor 112 may receive the first vapor working fluid stream 124 and the combined working fluid stream 135 as separate working fluid streams for pressurization, and discharge as the second pressurized working fluid stream 115. In this manner, each compressor 110 , 112 may include multiple inlets configured to receive separate working fluid streams, such as working fluid streams at different pressures.

[0047] The illustrated embodiment of the compressors 110, 112 configured to receive separate working fluid streams can limit the number of compressors utilized by the compressor system 106 to pressurize the working fluid from the economizer system 116. For example, at least one of the compressors 110, 112 can receive multiple vapor working fluid streams directly from the economizer system 116. Thus, a smaller number of compressors can be utilized to pressurize the vapor working fluid streams from the economizer system 116 as compared to a compressor system that includes a separate compressor dedicated to receiving and pressurizing each respective vapor working fluid stream from the economizer system 116. Thus, the cost and / or complexity associated with manufacturing and / or operating the illustrated compressor system 106 can be reduced.

[0048] Although the compressor system 106 of the illustrated vapor compression system 100 includes two compressors 110, 112 configured to receive vapor working fluid streams 124, 126, 128 from an economizer system 116, the compressor system 106 may have any suitable number of compressors 110, 112 in an additional or alternative HVAC&R system. For example, the number of compressors 110, 112 utilized in the compressor system 106 may be based on the number of economizers 118, 120, 122 of the economizer system 116. For example, three compressors may be utilized to pressurize a vapor working fluid stream from an economizer system 116 having five economizers, seven compressors may be utilized to pressurize a vapor working fluid stream from an economizer system 116 having seven economizers, and so on. In such embodiments, each compressor may receive multiple (e.g., two) separate working fluid streams for pressurization.

[0049] Figure 6 1 is a partial cross-sectional side view of an embodiment of a compressor 160 (e.g., a compressor impeller system, a single-stage energy-saving compressor), such as compressor 110 and / or compressor 112. The compressor 160 may include a housing 162 (e.g., a compressor housing) in which an impeller 164 may be disposed. A first working fluid stream 166 (e.g., a suction working fluid stream 113, a first pressurized working fluid stream 114, a second vapor working fluid 126, a combined working fluid stream 135, a main suction stream) may enter the housing 162 at a suction port 168 (e.g., a first inlet) and be directed toward the impeller 164. The compressor impeller 164 may be fixedly coupled to a shaft 170 that may rotate (e.g., via a motor) during operation of the compressor 160 to drive a corresponding rotation of the impeller 164. The impeller 164 driven into rotation may impart mechanical energy to the first working fluid stream 166. First working fluid stream 166 may exit impeller 164 through diffuser passage 172 (e.g., pressure recovery section) of compressor 160 and toward volute 174 of compressor 160. First working fluid stream 166 may be directed from volute 174 toward a condenser (e.g., condenser 102) and / or toward another compressor.

[0050] The compressor 160 may also be configured to receive a second working fluid stream 176 (e.g., a first vapor working fluid stream 124, a third vapor working fluid stream 128) from an economizer 178 (e.g., a first economizer 118, a third economizer 122). To this end, the compressor 160 includes an economizer inlet 180 (e.g., a second inlet) fluidly coupled to the economizer 178. The economizer inlet 180 may guide the second working fluid stream 176 into the housing 162 to combine with the first working fluid stream 166. For example, the housing 162 may include an opening 182 through which the second working fluid stream 176 may be guided to flow toward the first working fluid stream 166. The first working fluid stream 166 and the second working fluid stream 176 may be combined at a flow confluence point 183 within the housing 162. For example, the flow confluence point 183 may be positioned between the diffuser passage 172 and the impeller 164.

[0051] The initial pressure of the first working fluid stream 166 at the suction port 168 may be different from the initial pressure of the second working fluid stream 176 at the economizer inlet 180. In other words, the working fluid streams 166, 176 received by the compressor 160 may initially be at different pressures. For example, the initial pressure of the first working fluid stream 166 may be less than the initial pressure of the second working fluid stream 176. However, before the first working fluid stream 166 flows to reach the flow confluence point 183, the compressor 160 may partially pressurize the first working fluid stream 166 toward the initial pressure of the second working fluid stream 176 via the impeller 164. Therefore, at the flow confluence point 183, the partially pressurized first working fluid stream 166 and the received second working fluid stream 176 may have substantially similar pressures. The similar pressures of the working fluid streams 166, 176 at the flow confluence point 183 can facilitate directing the working fluid streams 166, 176 toward the diffuser passage 172, rather than, for example, in a reverse flow direction toward the suction port 168 and / or the economizer inlet 180 due to the pressure difference between the first working fluid stream 166 and the second working fluid stream 176 at the flow confluence point 183. In this way, the compressor 160 can easily direct each of the first working fluid stream 166 and the second working fluid stream 176 toward the volute 174 for discharge. The compressor 160 can further pressurize the working fluid streams 166, 176 directed downstream of the flow confluence point 183 and through the diffuser passage 172, such as to a common, increased pressure for discharge.

[0052] In certain embodiments, the impeller 164 may include blades 184 that may force the first working fluid stream 166 through the housing 162, through the diffuser passage 172, and to the volute 174 during rotation of the impeller 164. The impeller 164 may also include a shroud 186 that may be integral with the blades 184 to surround and cover the blades 184 (e.g., to shield a portion of the blades 184, such as the tip 185, from the housing 162). The first working fluid stream 166 may be directed through the impeller 164 within the shroud 186 toward the diffuser passage 172. In the illustrated embodiment, the second working fluid stream 176 is directed through the housing 162 and along a passage 188 extending between the shroud 186 and the housing 162 toward the diffuser passage 172 so that the second working fluid stream 176 can be combined with the first working fluid stream 166 (e.g., a partially pressurized first working fluid having a pressure substantially the same as that of the second working fluid stream 176) at the flow confluence point 183. The shroud 186 may prevent contact between the second working fluid stream 176 and the first working fluid stream 166 within the shroud 186. For example, the first working fluid stream 166 and the second working fluid stream 176 may combine with each other downstream of the tip 185 of the blade 184 relative to the flow through the compressor 160 and toward the diffuser passage 172. However, in additional or alternative embodiments, the impeller 164 may not include the shroud 186 and / or may include a shroud 186 that exposes a portion of the blade 184, such as the tip 185, to the housing 162. In such embodiments, the first working fluid stream 166 and the second working fluid stream 176 may combine with each other upstream of the tip 185 of the blade 184 relative to the flow of the working fluid through the compressor 160 and toward the diffuser passage 172. In any case, the suction port 168 and the economizer inlet 180 may enable the compressor 160 to receive separate working fluid streams for pressurization and discharge.

[0053] Figure 7 1 is a schematic diagram of an embodiment of a compressor system 106 having a first compressor 110, which may include a first compressor impeller 210, and a second compressor 112, which may include a second compressor impeller 212. The first compressor impeller 210 and the second compressor impeller 212 may be coupled to a common shaft 214. For example, the compressor system 106 may include a double-ended (e.g., double-ended dual single-stage compressor) configuration, wherein the first compressor impeller 210 is coupled at a first end 216 of the shaft 214, and the second compressor impeller 212 is coupled at a second end 218 of the shaft 214 opposite the first end 216. Thus, rotation of the shaft 214 via the motor 220 may drive rotation of each of the first compressor impeller 210 and the second compressor impeller 212.

[0054] The first compressor 110 may receive the suction working fluid stream 113 from, for example, the evaporator 104 via the first inlet 130 (e.g., the suction port) and pressurize the suction working fluid stream 113. The first compressor 110 may also receive the third vapor working fluid stream 128 from the third economizer 122 via the second inlet 132 (e.g., the economizer inlet), and the suction working fluid stream 113 (e.g., the partially pressurized suction working fluid stream 113) and the third vapor working fluid stream 128 may be combined and flow toward the first volute 224. The first compressor 110 may discharge the suction working fluid stream 113 and the third vapor working fluid stream 128 from the first volute 224 toward the second compressor 112 as the first pressurized working fluid stream 114.

[0055] The second compressor 112 may receive the first pressurized working fluid stream 114 via a third inlet 134 (e.g., a suction inlet). The second compressor 112 may additionally or alternatively receive the second vapor working fluid stream 126 from the second economizer 120 via the third inlet 134. The second compressor 112 may pressurize the first pressurized working fluid stream 114 and / or the second vapor working fluid stream 126 (e.g., as a combined working fluid stream 135), and direct the first pressurized working fluid stream 114 and / or the second vapor working fluid stream 126 (e.g., a combined working fluid stream 135) toward the second volute 226. The second compressor 112 may further receive the first vapor working fluid 124 from the first economizer 118 via a fourth inlet 136 (e.g., an economizer inlet). The first vapor working fluid 124 may be combined with the first pressurized working fluid stream 114 and / or the second vapor working fluid stream 126 (e.g., the first pressurized working fluid stream 114 and / or the second vapor working fluid stream 126 partially pressurized by the second compressor 112, the combined working fluid stream 135) and flow toward the second volute 226. The second compressor 112 may then discharge the combination of the first pressurized working fluid stream 114, the first vapor working fluid stream 124, and / or the second vapor working fluid stream 126 as the second pressurized working fluid stream 115 toward the condenser 102.

[0056] In the illustrated embodiment, the first compressor 110 and the second compressor 112 are oriented in opposite directions from each other. For example, the first inlet 130 of the first compressor 110 and the third inlet 134 of the second compressor 112 face away from each other. To this end, the rotation of the shaft 214 caused by the operation of the motor 220 can drive the first compressor impeller 210 to rotate in a first rotational direction 228 (e.g., clockwise rotation) and drive the second compressor impeller 212 to rotate in a second rotational direction 230 (e.g., counterclockwise rotation) opposite to the first rotational direction 228. In additional or alternative embodiments, the first compressor 110 and the second compressor 112 may be oriented in opposite directions from each other, such that the first inlet 130 of the first compressor 110 and the third inlet 134 of the second compressor 112 face each other. In further embodiments, the first compressor 110 and the second compressor 112 may be oriented in the same direction (e.g., the first inlet 130 and the third inlet 134 face the same direction).

[0057] Figure 8 1 is a schematic diagram of an embodiment of a compressor system 106 having a first compressor 110 and a second compressor 112. For example, the first compressor 110 may receive and pressurize the suction working fluid stream 113 (e.g., from the evaporator 104) and / or the third vapor working fluid stream 128 (e.g., from the third economizer 122) to discharge the suction working fluid stream 113 and / or the third vapor working fluid stream 128 as the first pressurized working fluid stream 114 toward the second compressor 112. The second compressor 112 may receive and pressurize the first pressurized working fluid stream 114, the first vapor working fluid stream 124 (e.g., from the first economizer 118), and / or the second vapor working fluid stream 126 (e.g., from the second economizer 120) to discharge the first pressurized working fluid stream 114, the first vapor working fluid stream 124, and / or the second vapor working fluid stream 126 as the second pressurized working fluid stream 115 toward the condenser 102.

[0058] In the illustrated embodiment, the first compressor 110 and the second compressor 112 are oriented in the same direction. For example, each of the first inlet 130 and the second inlet 134 may face in a common direction, such as in direction 250. The orientation of the compressors 110, 112 in the same direction may enable rotation of the shaft 214, such as caused by operation of the motor 220, to drive rotation of the compressor impellers 210, 212 in the same rotational direction, such as the first rotational direction 228.

[0059] In the illustrated embodiment, the compressors 110, 112 are positioned at a common end 252 (e.g., the first end 216) of the shaft 214. As an example, the common end 252 may include a drive end of the shaft 214, or an end of the shaft 214 that may receive a significant radial load or force (e.g., a force imparted perpendicular to the axis of rotation of the shaft 214). As another example, the common end 252 may include a non-drive end of the shaft 214 opposite the drive end, such as for a cantilever (e.g., double cantilever, cantilever dual single stage) configuration of the compressor system 106. In addition, although in the illustrated embodiment the compressors 110, 112 are oriented such that the first inlet 130 and the third inlet 134 face away from the motor 220, in alternative embodiments the compressors 110, 112 may be oriented such that the first inlet 130 and the third inlet 134 face the motor 220.

[0060] Fig. 9 is a schematic diagram of an embodiment of a compressor system 106 having a first compressor 110 and a second compressor 112. In the illustrated embodiment, the compressor impellers 210, 212 are coupled to different shafts. For example, the first compressor impeller 210 may be coupled to a first shaft 280 driven by a first motor 282, and the second compressor impeller 212 may be coupled to a second shaft 284 driven by a second motor 286. In this manner, operation of the first motor 282 may rotate the first shaft 280 to drive rotation of the first compressor impeller 210, but the first motor 282 may not directly drive rotation of the second compressor impeller 212 via the second shaft 284, and operation of the second motor 286 may rotate the second shaft 284 to drive rotation of the second compressor impeller 212, but the second motor 286 may not directly drive rotation of the first compressor impeller 210 via the first shaft 280. In this manner, the compressors 110, 112 (e.g., the rotational speeds of the compressor impellers 210, 212) may be controlled independently of each other. However, the operation of the compressors 110, 112 may be generally similar to the operation described above, wherein the first compressor 110 may receive and pressurize the intake working fluid stream 113 and / or the third vapor working fluid stream 128 to discharge the intake working fluid stream 113 and / or the third vapor working fluid stream 128 as the first pressurized working fluid stream 114 toward the second compressor 112. In addition, the second compressor 112 may receive and pressurize the first pressurized working fluid stream 114, the first vapor working fluid stream 124, and / or the second vapor working fluid stream 126 (e.g., the combined working fluid stream 135 and the first vapor working fluid stream 124) to discharge the first pressurized working fluid stream 114, the first vapor working fluid stream 124, and / or the second vapor working fluid stream 126 as the second pressurized working fluid stream 115 toward the condenser 102.

[0061] The compressors 110, 112 may be oriented such that the first inlet 130 and the third inlet 134 face the same direction, such as direction 250. In alternative embodiments, the compressors 110, 112 may be oriented in different directions, such as an arrangement in which the first inlet 130 and the third inlet 134 face opposite directions, an arrangement in which the first inlet 130 and the third inlet 134 face crosswise to each other, etc. Indeed, the shafts 280, 284 may be arranged in any suitable manner to orient the compressors 110, 112 in corresponding directions.

[0062] In the above-described embodiments, the compressors 110, 112 are positioned in a series flow arrangement, wherein the working fluid may be directed from the first compressor 110 to the second compressor 112. In additional or alternative embodiments, the compressors 110, 112 may be positioned in a parallel flow arrangement, wherein the working fluid may be directed to one of the compressors 110, 112 but not the other of the compressors 110, 112 before being directed to the condenser 102. For example, each of the first compressor 110 and the second compressor 112 may discharge a respective working fluid stream directly to the condenser 102.

[0063] Fig.10 is a schematic diagram of an embodiment of a vapor compression system 100 in which a first compressor 110 and a second compressor 112 are in a parallel flow arrangement. The first compressor 110 may receive an intake working fluid stream 113 (e.g., from the evaporator 104 via a first inlet 130) and / or a third vapor working fluid stream 128 (e.g., from the third economizer 122 via a second inlet 132) and pressurize them to provide a first pressurized working fluid stream 114. However, the first compressor 110 may discharge the first pressurized working fluid stream 114 to the condenser 102 instead of the second compressor 112. Therefore, the first pressurized working fluid stream 114 may bypass the second compressor 112 to flow directly from the first compressor 110 to the condenser 102. The second compressor 112 may receive the first vapor working fluid stream 124 (e.g., via the fourth inlet 136) and / or the second vapor working fluid stream 126 (e.g., via the third inlet 134) and pressurize them to discharge the first vapor working fluid stream 124 and / or the second vapor working fluid stream 126 as a second pressurized working fluid stream 115 to the condenser 102. For example, the first pressurized working fluid stream 114 and the second pressurized working fluid stream 115 may be combined and flow to the condenser 102 via a common inlet 320 of the condenser 102. In additional or alternative embodiments, the first pressurized working fluid stream 114 and the second pressurized working fluid stream 115 may flow to the condenser 102 as separate fluid streams, such as via different inlets of the condenser 102. In a parallel flow arrangement, the first compressor 110 and the second compressor 112 may be coupled to a common shaft or to separate shafts.

[0064] In addition to or in lieu of embodiments of compressors 110, 112 having multiple inlets configured to receive separate working fluid streams (e.g., as represented by compressor 160), vapor compression system 100 may also include compressor embodiments having a single inlet configured to receive a single working fluid stream. For example, Fig.11 is a schematic diagram of an embodiment of a vapor compression system 100 having a first compressor 110 and a third compressor 350. The first compressor 110 can receive separate working fluid streams, such as a suction working fluid stream 113 via a first inlet 130 and a second vapor working fluid stream 126 via a second inlet 132. The first compressor 110 can pressurize the suction working fluid stream 113 and / or the second vapor working fluid stream 126 to provide a first pressurized working fluid stream 114.

[0065] The third compressor 350 may be configured to receive a single working fluid stream. For example, the third compressor 350 may include a fifth inlet 352 that may receive the first pressurized working fluid stream 114. Thus, the first compressor 110 and the third compressor 350 may be in a series flow arrangement, wherein the third compressor 350 is positioned downstream of the first compressor 110 relative to the flow of the working fluid through the compressor system 106. In some embodiments, the first vapor working fluid stream 124 directed by the first economizer 118 may be combined with the first pressurized working fluid stream 114 as a combined working fluid stream 354, and the third compressor 350 may receive the combined working fluid stream 354 and pressurize it to provide a second pressurized working fluid stream 115 for discharge toward the condenser 102. However, in addition to the fifth inlet 352, the third compressor 350 may not include an inlet, and therefore may not receive a separate working fluid stream (e.g., a third vapor working fluid stream 128 from the third economizer 122, which would otherwise be incorporated into the economizer system 116).

[0066] Fig.12is a schematic diagram of an embodiment of a compressor system 106 having a first compressor 110 and a third compressor 350. The first compressor 110 may receive an intake working fluid stream 113 and / or a second vapor working fluid stream 126 and pressurize them for discharge as a first pressurized working fluid stream 114 toward the third compressor 350. The third compressor 350 may receive the first pressurized working fluid stream 114 and / or the first vapor working fluid stream 124 (e.g., a combined working fluid stream 354) via a fifth inlet 352 and pressurize them for discharge as a second pressurized working fluid stream 115 toward the condenser 102. As an example, the third compressor 350 may include a third compressor impeller 380 that may impart mechanical energy to the first pressurized working fluid stream 114 and / or the first vapor working fluid stream 124 (e.g., the combined working fluid stream 354) to direct the first pressurized working fluid stream 114 and / or the first vapor working fluid stream 124 to a third volute 382. The third compressor 350 may discharge the first pressurized working fluid stream 114 and / or the first vapor working fluid stream 124 from the third volute 382 toward the condenser 102 as a second pressurized working fluid stream 115 .

[0067] In the illustrated embodiment, the first compressor impeller 210 and the third compressor impeller 380 are coupled to different shafts. For example, the first compressor impeller 210 may be coupled to a first shaft 280 driven by a first motor 282, and the third compressor impeller 380 may be coupled to a second shaft 284 driven by a second motor 286. Thus, operation of the motors 282, 286 may cause respective rotations of the compressors 110, 350 (e.g., rotations of the respective impellers 210, 380). In additional or alternative embodiments, the first compressor impeller 210 and the third compressor impeller 380 may be coupled to a common shaft (e.g., shaft 214) driven by a single motor (e.g., motor 220), such as at opposite ends of the shaft and / or at a common end of the shaft. Thus, operation of the motors may cause rotations of both compressors 110, 350.

[0068] Fig.13is a schematic diagram of an embodiment of a compressor system 106 having a first compressor 110 and a third compressor 350 in a series flow arrangement. In the illustrated embodiment, the first compressor 110 is positioned downstream of the third compressor 350 relative to the flow of the working fluid through the compressor system 106. As an example, the third compressor 350 may receive the suction working fluid stream 113 from the evaporator 104 via the fifth inlet 352, pressurize the suction working fluid stream 113, and discharge the pressurized suction working fluid stream 113 as the first pressurized working fluid stream 114 toward the first compressor 110. The first compressor 110 may receive the pressurized suction working fluid stream 113 (e.g., the first pressurized working fluid stream 114) and / or the second vapor working fluid stream 126 (e.g., the combined working fluid stream 117) via the first inlet 130. The first compressor 110 may also receive the first vapor working fluid stream 124 via the second inlet 132. The first compressor 110 may pressurize the suction working fluid stream 113 , the first vapor working fluid stream 124 , and / or the second vapor working fluid stream 126 , and discharge the pressurized working fluid stream as a second pressurized working fluid stream 115 to the condenser 102 .

[0069] Fig.14 is a schematic diagram of an embodiment of a compressor system 106 having a first compressor 110 and a third compressor 350 in a parallel flow arrangement. For example, the first compressor 110 may receive and pressurize the suction working fluid stream 113 and / or the second vapor working fluid stream 126 to provide a first pressurized working fluid stream 114. The first compressor 110 may then discharge the first pressurized working fluid stream 114 to the condenser 102 and bypass the third compressor 350. The third compressor 350 may receive and pressurize the first vapor working fluid stream 124 to discharge the pressurized first vapor working fluid stream 124 as the second pressurized working fluid stream 115 to the condenser 102 and bypass the first compressor 110. In additional or alternative embodiments, the third compressor 350 may receive and pressurize the suction working fluid stream 113 for discharge to the condenser 102 and bypass the first compressor 110, and the first compressor 110 may receive and pressurize the second vapor working fluid stream 126 and / or the first vapor working fluid stream 124 for discharge to the condenser 102 and bypass the third compressor 350. In any of these embodiments, the first compressor 110 and the third compressor 350 may be coupled to a common shaft or to separate shafts.

[0070] Although only certain features and embodiments of the present disclosure are shown and described, many modifications and changes (such as the size, dimensions, structure, shape and proportion of various elements, changes in parameter values ​​(e.g., temperature, pressure, etc.), installation arrangements, material use, color, orientation, etc.) may occur to those skilled in the art without substantially departing from the novel teachings and advantages of the subject matter described in the claims. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. Therefore, it should be noted that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the present disclosure. In addition, in order to provide a concise description of the exemplary embodiments, all features of the actual implementation may not be described (i.e., those features that are not related to the best mode currently contemplated for implementing the present disclosure, or those features that are not related to implementing the claimed embodiments). It should be understood that in the development of any such actual implementation, as in any engineering technology or design project, a large number of implementation-specific decisions may be made. Such development work may be complex and time-consuming, but for ordinary technicians who benefit from the present disclosure, these are routine tasks of design, manufacture and production without excessive experimentation.

[0071] The technology presented and claimed herein is referenced and applied to substantial objects and specific examples of a practical nature that improve the art in a demonstrable manner and are therefore not abstract, intangible, or purely theoretical. In addition, if any claim appended to the end of this specification contains one or more elements expressed as "means for [performing] [the function] ..." or "steps for [performing] [the function] ...", it is expected that such elements will be interpreted in accordance with 35 U.S.C. 112(f). However, for any claim containing elements specified in any other manner, it is intended that such elements will not be interpreted in accordance with 35 U.S.C. 112(f).

Claims

1. A heating, ventilation, air conditioning and / or refrigeration (HVAC&R) system configured to circulate a working fluid therethrough, The HVAC&R system comprises: an economizer system comprising a first economizer and a second economizer, wherein the first economizer is configured to reduce a first pressure of the working fluid in the first economizer to provide a first vapor working fluid flow, and the second economizer is configured to reduce a second pressure of the working fluid in the second economizer to provide a second vapor working fluid flow; and A compressor system comprising: a first compressor stage including a first inlet and a second inlet, wherein the first compressor stage is configured to receive the second vapor working fluid flow from the second economizer via the second inlet, and the a first compressor stage configured to receive an additional working fluid stream separated from the second vapor working fluid stream via the first inlet; and A second compressor stage includes a third inlet, wherein the second compressor stage is configured to receive the first vapor working fluid flow from the first economizer via the third inlet.

2. The HVAC&R system of claim 1, comprising: Evaporator, It is configured to place the working fluid in heat exchange relationship with a cooling fluid, and the additional working fluid flow is received from the evaporator.

3. The HVAC&R system of claim 1 , wherein the first compressor stage is configured to pressurize the second vapor working fluid flow and the additional working fluid flow for discharge as a pressurized working fluid flow to the second compressor stage, and the second compressor stage is configured to receive the pressurized working fluid flow from the first compressor stage via a fourth inlet.

4. The HVAC&R system of claim 3, wherein the second compressor stage is configured to pressurize the first vapor working fluid stream and the pressurized working fluid stream for discharge to a condenser for cooling via the condenser.

5. The HVAC&R system of claim 3, wherein the economizer system includes a third economizer configured to reduce a third pressure of the working fluid in the third economizer to provide a third vapor working fluid flow, and the second compressor stage is configured to receive the third vapor working fluid flow from the third economizer via the fourth inlet.

6. The HVAC&R system of claim 5, wherein the second compressor stage is configured to receive the pressurized working fluid stream and the third vapor working fluid stream as a combined working fluid stream via the fourth inlet.

7. The HVAC&R system of claim 1, comprising: A condenser is configured to cool the working fluid, wherein the economizer system is configured to receive the working fluid from the condenser.

8. The HVAC&R system of claim 1, wherein the first compressor stage includes a first impeller, the second compressor stage includes a second impeller, and the first impeller and the second impeller are attached to a common shaft.

9. The HVAC&R system of claim 1, wherein the first compressor stage includes a first impeller, the second compressor stage includes a second impeller, and the first impeller and the second impeller are attached to separate shafts.

10. The HVAC&R system of claim 1, wherein the first economizer is configured to reduce the pressure of the working fluid in the first economizer to provide a first liquid working fluid flow and a first vapor working fluid flow, the first economizer is configured to discharge the first liquid working fluid flow to the second economizer, and the second economizer is configured to reduce the pressure of the first liquid working fluid flow in the second economizer to provide a second liquid working fluid flow and a second vapor working fluid flow.

11. A vapor compression system for a heating, ventilation, air conditioning and / or refrigeration (HVAC&R) system, wherein the vapor compression system is configured to circulate a working fluid therethrough, And the vapor compression system comprises: a first economizer configured to reduce a first pressure of the working fluid in the first economizer to provide a first vapor working fluid flow; a second economizer configured to reduce a second pressure of the working fluid in the second economizer to provide a second vapor working fluid flow; an evaporator configured to place the working fluid in the evaporator in heat exchange relationship with a cooling fluid to provide a third vapor working fluid stream; and A compressor system comprising: a first compressor stage comprising a first inlet and a second inlet, wherein the first inlet is configured to receive a first working fluid stream and the second inlet is configured to receive a second working fluid stream separate from the first working fluid stream; and A second compressor stage includes a third inlet configured to receive a third working fluid stream, wherein each of the first working fluid stream, the second working fluid stream, and the third working fluid stream includes a different one of the first vapor working fluid stream, the second vapor working fluid stream, and the third vapor working fluid stream.

12. The vapor compression system of claim 11, wherein each of the first compressor stage and the second compressor stage is a single-stage energy-saving compressor, the first compressor stage includes a first impeller, the second compressor stage includes a second impeller, and the first impeller and the second impeller are connected to different shafts.

13. A vapor compression system according to claim 11, wherein the first compressor stage is configured to receive the third vapor working fluid flow as the first working fluid flow from the evaporator via the first inlet, and is configured to receive the second vapor working fluid flow as the second working fluid flow separately from the second economizer via the second inlet, and wherein the second compressor stage is configured to receive the first vapor working fluid flow as the third working fluid flow from the first economizer via the third inlet.

14. The vapor compression system of claim 11, comprising: A condenser is configured to cool the working fluid, wherein the first economizer is configured to receive the working fluid from the condenser.

15. A heating, ventilation, air conditioning and / or refrigeration (HVAC&R) system configured to circulate a working fluid therethrough, The HVAC&R system comprises: an economizer system comprising one or more economizers configured to reduce a pressure of the working fluid in the one or more economizers to provide one or more vapor working fluid streams; and A compressor system comprising: a first compressor stage comprising a first inlet and a second inlet, wherein the first compressor stage is configured to receive a first vapor working fluid stream of the one or more vapor working fluid streams via the second inlet, and the first compressor stage is configured to receive an additional working fluid stream separate from the first vapor working fluid stream via the first inlet; and A second compressor stage includes a third inlet, wherein the second compressor stage is configured to receive a second vapor working fluid stream of the one or more vapor working fluid streams via the third inlet.

16. The HVAC&R system of claim 15, wherein the second compressor stage comprises a fourth inlet, wherein the first compressor stage is configured to discharge the first vapor working fluid flow and the additional working fluid flow as a pressurized working fluid flow, and wherein the second compressor stage is configured to receive the pressurized working fluid flow via the fourth inlet.

17. The HVAC&R system of claim 16, wherein the second compressor stage is configured to receive the pressurized working fluid stream and a third vapor working fluid stream of the one or more vapor working fluid streams as a combined working fluid stream via the fourth inlet.

18. The HVAC&R system of claim 17, wherein a first economizer among the one or more economizers is configured to provide the first vapor working fluid flow, a second economizer among the one or more economizers is configured to provide the second vapor working fluid flow, and a third economizer among the one or more economizers is configured to provide the third vapor working fluid flow.

19. The HVAC&R system of claim 15, comprising: a condenser configured to cool the working fluid, wherein the economizer system is configured to receive the working fluid from the condenser; as well as An evaporator is configured to place the working fluid in heat exchange relationship with a cooling fluid, wherein the first compressor stage is configured to receive the additional flow of working fluid from the evaporator.

20. The HVAC&R system of claim 15, wherein the first compressor stage includes a first impeller, the second compressor stage includes a second impeller, and wherein the first impeller and the second impeller are coupled to a common shaft.

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