WO2023244833A1

WO2023244833A1 - Compressor system for heating, ventilation, air conditioning, and/or refrigeration system

Info

Publication number: WO2023244833A1
Application number: PCT/US2023/025616
Authority: WO
Inventors: Paul Eric LE SAUSSE; Damien Jean Daniel Arnou; Francois Charles André CLUNET; Jeb William SCHREIBER; Abdel Kader JANNOUN
Original assignee: Johnson Controls Tyco IP Holdings LLP
Priority date: 2022-06-17
Filing date: 2023-06-16
Publication date: 2023-12-21

Abstract

A heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system (100), comprising an economizer system (104) configured to reduce a pressure of a refrigerant to provide a first vapor refrigerant flow and a second vapor refrigerant flow. The HVAC&R system (100) also includes an auxiliary compressor system (106) that has a first auxiliary compressor (160) configured to receive the first vapor refrigerant flow from the economizer system (104) and pressurize the first vapor refrigerant flow to provide a first pressurized vapor refrigerant flow and a second auxiliary compressor (162) configured to receive the second vapor refrigerant flow from the economizer system (104) and pressurize the second vapor refrigerant flow to provide a second pressurized vapor refrigerant flow. The auxiliary compressor system (106) is configured to discharge a combined vapor refrigerant flow comprising the first pressurized vapor refrigerant flow and the second pressurized vapor refrigerant flow toward a condenser (34) of the HVAC&R system (100).

Description

COMPRESSOR SYSTEM FOR 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 Application Serial No. 63/353,343, entitled “COMPRESSOR SYSTEM FOR HEATING, VENTILATION, AIR CONDITIONING, AND/OR REFRIGERATION SYSTEM”, filed lune 17, 2022, which is hereby incorporated by reference.

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 some embodiments, the chiller system may include an economizer configured to improve an efficiency of the chiller 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 reduce a pressure of the working fluid to further cool the working fluid and separate the working fluid into liquid phase working fluid and vapor phase working fluid. The economizer may direct the liquid phase working fluid to a second heat exchanger (e.g., an evaporator) configured to place the working fluid in the heat exchange relationship with the cooling fluid. The economizer may direct the vapor phase working fluid to a compressor for pressurization. Unfortunately, existing chiller systems that include economizers may operate inefficiently.

SUMMARY

[0004] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0005] In one embodiment, a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes an economizer system configured to reduce a pressure of a first portion of a refrigerant, an auxiliary compressor system configured to receive the first portion of the refrigerant from the economizer system, where the auxiliary compressor system comprises a first auxiliary compressor and a second auxiliary compressor, and a primary compressor. The HVAC&R system also includes a condenser configured to receive the first portion of the refrigerant from the auxiliary compressor system and a second portion of the refrigerant from the primary compressor.

[0006] In another embodiment, a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system, comprising an economizer system configured to reduce a pressure of a refrigerant to provide a first vapor refrigerant flow and a second vapor refrigerant flow. The HVAC&R system also includes an auxiliary compressor system that has a first auxiliary compressor configured to receive the first vapor refrigerant flow from the economizer system and pressurize the first vapor refrigerant flow to provide a first pressurized vapor refrigerant flow and a second auxiliary compressor configured to receive the second vapor refrigerant flow from the economizer system and pressurize the second vapor refrigerant flow to provide a second pressurized vapor refrigerant flow. The auxiliary compressor system is configured to discharge a combined vapor refrigerant flow comprising the first pressurized vapor refrigerant flow and the second pressurized vapor refrigerant flow toward a condenser of the HVAC&R system.

[0007] In still another embodiment, a compression system of a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes an auxiliary compressor system configured to receive a first portion of a refrigerant from an economizer system of the HVAC&R system. The auxiliary compression system includes a first auxiliary compressor and a second auxiliary compressor. The compression system also includes a primary compressor configured to receive a second portion of the refrigerant from an evaporator of the HVAC&R system.

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 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 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 schematic of an embodiment of the vapor compression system of FIG. 2, in accordance with an aspect of the present disclosure; [0014] FIG. 6 is a schematic of an embodiment of a vapor compression system that includes an economizer system and an auxiliary compressor system configured to receive working fluid from the economizer system, in accordance with an aspect of the present disclosure;

[0015] FIG. 7 is a schematic of an embodiment of a vapor compression system that includes an economizer system and an auxiliary compressor system configured to receive working fluid from the economizer system, in accordance with an aspect of the present disclosure;

[0016] FIG. 8 is a schematic of an embodiment of a vapor compression system that includes an economizer system and an auxiliary compressor system configured to receive working fluid from the economizer system, in accordance with an aspect of the present disclosure;

[0017] FIG. 9 is a schematic of an embodiment of a vapor compression system that includes an economizer system and an auxiliary compressor system configured to receive working fluid from the economizer system, in accordance with an aspect of the present disclosure;

[0018] FIG. 10 is a schematic of an embodiment of a vapor compression system that includes an economizer system and an auxiliary compressor system configured to receive working fluid from the economizer system, in accordance with an aspect of the present disclosure;

[0019] FIG. 11 is a schematic of an embodiment of a vapor compression system that includes an economizer system and an auxiliary compressor system configured to receive working fluid from the economizer system, in accordance with an aspect of the present disclosure;

[0020] FIG. 12 is a schematic of an embodiment of a vapor compression system that includes an economizer system and an auxiliary compressor system configured to receive working fluid from the economizer system, in accordance with an aspect of the present disclosure;

[0021] FIG. 13 is a graphical illustration of a vapor compression cycle, in accordance with an aspect of the present disclosure;

[0022] FIG. 14 is a graphical illustration of a vapor compression cycle, in accordance with an aspect of the present disclosure;

[0023] FIG. 15 is a graphical illustration of a vapor compression cycle, in accordance with an aspect of the present disclosure; and

[0024] FIG. 16 is a graphical illustration of a vapor compression cycle, in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

[0025] 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.

[0026] 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.

[0027] 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 circuit). The vapor compression system may include a compressor (e.g., a primary compressor) 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 toward 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. The compressor may then receive the working fluid from the evaporator for pressurization to restart the vapor compression cycle.

[0028] In some embodiments, the vapor compression system may include an economizer system configured to receive the working fluid from the condenser. The economizer system may be configured to reduce a pressure of the working fluid to further cool the working fluid and separate the working fluid into liquid working fluid and vapor working fluid. The economizer system may direct the liquid working fluid to the evaporator to enable the evaporator to place the liquid working fluid in a heat exchange relationship with the cooling fluid. The vapor working fluid may be directed from the economizer system toward the condenser. However, the vapor working fluid directed from the economizer system may not readily flow toward the condenser in some circumstances. For example, the working fluid pressurized by the compressor may also be directed toward the condenser to mix with the working fluid directed from the economizer system, but the working fluid from the compressor and the working fluid from the economizer system may be at different pressures. Such a pressure differential may disrupt flow of the working fluid to the condenser, such as by causing back flow of working fluid toward the compressor and/or toward the economizer. Thus, the working fluid may not efficiently flow toward the condenser from the economizer. It should be noted that reference to a element (e.g., a system, component, or the like) directing a fluid (e.g., refrigerant in a vapor or liquid phase) toward another element indicates that the element pressurizes, forces, guides (e.g., via piping, valves, mechanical operation), or the like the fluid directly or indirectly to the other element.

[0029] It is now recognized that improvements are desired for HVAC&R systems having an economizer system. The present disclosure is directed to incorporating an additional, auxiliary compressor system configured to receive vapor working fluid from an economizer system, pressurize the vapor working fluid, and direct the pressurized vapor working fluid toward the condenser. The auxiliary compressor system may pressurize the vapor working fluid toward the pressure of the working fluid pressurized by the compressor (e g., the primary compressor) to reduce a pressure differential between the respective working fluid flows directed toward the condenser, thereby facilitating efficient flow of the working fluid through the HVAC&R system. The auxiliary compressor system may include multiple auxiliary compressors that may be less costly than a single compressor that can handle the same load. Additionally or alternatively, each auxiliary compressor may occupy a smaller physical footprint than would be occupied by a single compressor to enable efficient usage of space via the HVAC&R system. As further described below, the auxiliary compressors may be configured in any suitable series flow arrangement and/or a parallel flow arrangement with respect to flow of the working fluid through the auxiliary compressor system to provide desirable pressurization of the vapor working fluid for flow toward the condenser. Thus, the auxiliary compressor system may improve operation of the HVAC&R system having the economizer without significantly increasing a manufacturing cost of and/or footprint occupied by the HVAC&R system.

[0030] Turning now to the drawings, FIG. l 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 atypical commercial setting. The HVAC&R system 10 may include a vapor compression system 14 (e.g., a chiller) that supplies a chilled liquid, which may be used to cool the building 12. The HVAC&R system 10 may also include a boiler 16 to supply warm liquid to heat the building 12 and an air distribution system which circulates air through the building 12. The air distribution system can also include an air return duct 18, an air supply duct 20, and/or an air handler 22. In some embodiments, the air handler 22 may include a heat exchanger that is connected to the boiler 16 and the vapor compression system 14 by conduits 24. The heat exchanger in the air handler 22 may receive either heated liquid from the boiler 16 or chilled liquid from the vapor compression system 14, depending on the mode of operation of the HVAC&R system 10. The HVAC&R system 10 is shown with a separate air handler on each floor of building 12, but in other embodiments, the HVAC&R system 10 may include air handlers 22 and/or other components that may be shared between or among floors.

[0031] 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 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.

[0032] 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-1234ze, R1233zd, hydrofluoro olefin (HFO), "natural" refrigerants like ammonia (NH3), R-717, carbon dioxide (CO2), R-744, or hydrocarbon based refrigerants, water vapor, or any other suitable refrigerant. In some embodiments, the vapor compression system 14 may be configured to efficiently utilize 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.

[0033] 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.

[0034] 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. 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.

[0035] 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.

[0036] 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). 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.

[0037] 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 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.

[0038] It should be appreciated that any of the features described herein may be incorporated with the vapor compression system 14 or any other suitable HVAC&R systems. For example, the present techniques may be incorporated with any HVAC&R system having an economizer, such as the intermediate vessel 70, and a compressor, such as the compressor 32. The discussion below describes the present techniques incorporated with embodiments of the compressor 32 configured as a single stage compressor. However, it should be noted that the systems and methods described herein may be incorporated with other embodiments of the compressor 32 and HVAC&R system 10.

[0039] The present disclosure is directed to a vapor compression system that includes an economizer system (e.g., an intermediate vessel) configured to receive refrigerant from a condenser and to separate the refrigerant into liquid refrigerant and vapor refrigerant. The economizer system may direct the liquid refrigerant to an evaporator of the vapor compression system to enable the evaporator to place the liquid refrigerant in a heat exchange relationship with a cooling fluid to cool the cooling fluid. The vapor compression system may include an auxiliary compressor system that has multiple auxiliary compressors configured to receive and pressurize the vapor refrigerant directed from the economizer system. The auxiliary compressor system may direct the pressurized vapor refrigerant to a condenser, which may cool the vapor refrigerant. For example, the auxiliary compressors of the auxiliary compressor system may be in a series flow arrangement and/or a parallel flow arrangement suitable for increasing the pressure of the vapor refrigerant to a desirable level for discharge toward the condenser. Additionally, the auxiliary compressors may be less costly and/or may occupy a smaller physical footprint as compared to conventional compressor embodiments, such as that of a primary compressor of the vapor compression system. Thus, the auxiliary compressor system may provide desirable operations without significantly increasing a manufacturing cost of and/or a physical footprint occupied by the HVAC&R system.

[0040] With the foregoing in mind, FIG. 5 is a schematic of an embodiment of a vapor compression system 100 that includes a primary compressor 102 (e.g., the compressor 32, a single stage compressor, a multistage compressor), the condenser 34, the evaporator 38, and an economizer system 104 (e.g., the intermediate vessel 70, an intercooler). The primary compressor 102 may include any suitable number of compressor stages, such as one compressor stage or two or more compressor stages. The vapor compression system 100 also includes an auxiliary compressor system 106 (e.g., a secondary compressor system, a parallel compressor system) fluidly coupled to the economizer system 104. The auxiliary compressor system 106 may draw vapor refrigerant from the economizer system 104, compress the vapor refrigerant, and discharge the compressed vapor refrigerant toward the condenser 34. As an example, the auxiliary compressor system 106, instead of the primary compressor 102, may receive the vapor refrigerant from economizer system 104. The auxiliary compressor system 106 may pressurize the received vapor refrigerant and direct the pressurized vapor refrigerant toward the condenser 34 and bypass the primary compressor 102.

[0041] In some embodiments, the auxiliary compressor system 106 may increase the pressure of the vapor refrigerant toward that of the vapor refrigerant pressurized by the primary compressor 102. For example, a first pressure of the vapor refrigerant directed from the primary compressor 102 into the condenser 34 (e.g., via a first condenser inlet 108) may be similar or substantially the same as a second pressure of the vapor refrigerant directed from the auxiliary compressor system 106 into the condenser 34 (e.g., via a second condenser inlet 110). Pressurization of the refrigerant flows to approximately the same pressure may reduce disruptions to refrigerant flow toward the condenser 34 (e.g., by blocking back flow of refrigerant through the first condenser inlet 108 and/or through the second condenser inlet 110) that may otherwise occur because of a pressure differential between the respective refrigerant flows from the primary compressor 102 and from the economizer system 104. As such, the refrigerant may more readily flow through the condenser 34. For example, a desirable flow (e.g., a target flow rate) of refrigerant through the vapor compression system 100 and/or a desirable cooling of the refrigerant provided via the condenser 34 may be achieved. In certain embodiments or operational configurations, it should be noted that the primary compressor 102 provides substantially all of the compression head from an outlet 112 of the evaporator 38 to an outlet 114 of the primary compressor 102 (and the inlet 108 to the condenser 34 from the primary compressor 102). The auxiliary compressor system 106 provides a pressure boost to the refrigerant entering the condenser 34 from the economizer system 104.

[00421 An amount of pressurization provided by the auxiliary compressor system 106 may be less than that provided by the primary compressor 102. By way of example, the pressure of the vapor refrigerant directed from the economizer system 104 to the auxiliary compressor system 106 may be greater than the pressure of the refrigerant directed from the evaporator 38 to the primary compressor 102. As such, a first pressure differential between the pressure of the refrigerant received by the auxiliary compressor system 106 and a corresponding target pressure for pressurization by the auxiliary compressor system 106 may be less than a second pressure differential between the pressure of the refrigerant received by the primary compressor 102 and a corresponding target pressure for pressurization by the primary compressor 102. For this reason, a selected embodiment of a compressor utilized by the auxiliary compressor system 106 may be different than the embodiment of the primary compressor 102 to provide the desirable pressurization of the refrigerant flow from the economizer system 104. For instance, a design specification and/or operation of the auxiliary compressor system 106 may be different than that of the primary compressor 102. Indeed, as further described herein, the auxiliary compressor system 106 may include auxiliary compressors that are associated with a reduced cost, a reduced size, an increased configurability, and so forth. Thus, the auxiliary compressor system 106 may provide desirable operation, reduced cost of manufacture, improved ease of installation, and so forth associated with the vapor compression system 100. [0043] FIG. 6 is a schematic of an embodiment of the vapor compression system 100 that includes the economizer system 104 and the auxiliary compressor system 106. The economizer system 104 may include a plurality of economizers (e.g., economizer stages) that are each configured to reduce a pressure of a refrigerant flow. For example, a first economizer 140 (e.g., a first economizer stage) may receive the refrigerant from the condenser 34, reduce a pressure of the refrigerant to vaporize a portion of the refrigerant, and separate the refrigerant into liquid refrigerant and vapor refrigerant. The first economizer 140 may direct the vapor refrigerant as a first vapor refrigerant flow 142 toward the auxiliary compressor system 106, and the first economizer 140 may direct the liquid refrigerant as a first liquid refrigerant flow 144 to a second economizer 146. The second economizer 146 may reduce the pressure of the first liquid refrigerant flow 144 received from the first economizer 140 to vaporize a portion of the refrigerant and separate the refrigerant into liquid refrigerant and vapor refrigerant. The second economizer 146 may direct the vapor refrigerant as a second vapor refrigerant flow 148 toward the auxiliary compressor system 106, and the second economizer 146 may direct the liquid refrigerant as a second liquid refrigerant flow 150 to a third economizer 152. The third economizer 152 may further reduce a pressure of the second liquid refrigerant flow 150 received from the second economizer 146 to vaporize a portion of the refrigerant and separate the refrigerant into liquid refrigerant and vapor refrigerant. The third economizer 152 may direct the vapor refrigerant as a third vapor refrigerant flow 154 toward the auxiliary compressor system 106, and the third economizer 152 may direct the liquid refrigerant as a third liquid refrigerant flow 156 to the evaporator 38. By further reducing the pressure of the refrigerant, the second economizer 146 and/or the third economizer 152 may increase cooling of the refrigerant prior to discharge toward the evaporator 38, thereby increasing an amount of cooling provided by the refrigerant flow in evaporator 38 to the cooling fluid and increasing efficient operation of the vapor compression system 100 to condition the cooling fluid.

[0044] In some embodiments, each economizer 140, 146, 152 may be separate chambers, compartments, volumes, or spaces of a common or the same economizer enclosure, housing, or shell 158. That is, the economizer system 104 may include a single economizer enclosure 158 that may enclose multiple economizers 140, 146, 152 configured to reduce the pressure of the refrigerant (e.g., via stages). For instance, each economizer 140, 146, 152 may be separated from one another within the economizer enclosure 158 via a partition, a divider, a wall, a plate, and the like. In additional or alternative embodiments, each economizer 140, 146, 152 may have a respective enclosure, and the economizers 140, 146, 152 may therefore be separate components of one another. Further, each of the economizers 140, 146, 152 may include or be associated with one or more valves (e.g., expansion valves) to facilitate pressure drop relative to the respective economizer.

[00451 The auxiliary compressor system 106 may receive each of the vapor refrigerant flows 142, 148, 154 and pressurize the vapor refrigerant flows 142, 148, 154 for discharge toward the condenser 34 (e.g., via the second condenser inlet 110). For example, the auxiliary compressor system 106 may increase a respective pressure of each vapor refrigerant flow 142, 148, 154 toward the pressure of a primary refrigerant flow 159 directed from the primary compressor 102 to reduce a pressure differential between the primary refrigerant flow 159 directed from the primary compressor 102 to the condenser 34 and the pressurized vapor refrigerant flows directed from the auxiliary compressor system 106 to the condenser 34. Thus, the auxiliary compressor system 106 may facilitate flow of refrigerant to and/or through the condenser 34. Because the auxiliary compressor system 106 receives input from each of the economizers 140, 146, 152, the auxiliary compressor system 106 operates to increase differently pressurized flows (the vapor refrigerant flows 142, 148, 154) toward the pressure of the primary refrigerant flow 159.

[0046] As an example, the auxiliary compressor system 106 may include a plurality of auxiliary compressors that are in a parallel flow arrangement. That is, each auxiliary compressor may receive a respective one of the vapor refrigerant flows 142, 148, 154 from the economizer system 104. For instance, a first auxiliary compressor 160 may receive the first vapor refrigerant flow 142 from the first economizer 140, a second auxiliary compressor 162 may receive the second vapor refrigerant flow 148 from the second economizer 146, and a third auxiliary compressor 164 may receive the third vapor refrigerant flow 154 from the third economizer 152. The auxiliary compressors 160, 162, 164 may pressurize the vapor refrigerant flows 142, 148, 154, respectively, for discharge toward the condenser 110. That is, the first auxiliary compressor 160 may pressurize the first vapor refrigerant flow 142 to provide a first pressurized vapor refrigerant flow 166 for discharge toward the condenser 110, the second auxiliary compressor 162 may pressurize the second vapor refrigerant flow 148 to provide a second pressurized vapor refrigerant flow 168 for discharge toward the condenser 110, and the third auxiliary compressor 164 may pressurize the third vapor refrigerant flow 154 to provide a third pressurized vapor refrigerant flow 170 for discharge toward the condenser 110. The pressurized vapor refrigerant flows 166, 168, 170 may combine to provide a combined pressurized vapor refrigerant flow 172 that may be received by the condenser 34.

[0047] As noted above, in some embodiments, the respective amounts of pressurization provided by the auxiliary compressors 160 may be different from one another. For example, each auxiliary compressor 160, 162, 164 may pressurize the respective vapor refrigerant flows 142, 148, 154 to approximately the same target pressure (e.g., substantially equal to the pressure of the primary refrigerant flow 159). However, the respective pressures of the vapor refrigerant flows 142, 148, 154 received by the auxiliary compressors 160, 162, 164 may initially have different pressures. For instance, because the third economizer 152 provides additional pressure reduction of the second liquid refrigerant flow 150 from the second economizer 146, the pressure of the third vapor refrigerant flow 154 may be less than the pressure of the second vapor refrigerant flow 148. Thus, a pressure differential between the pressure of the third vapor refrigerant flow 154 and the target pressure may be greater than a pressure differential between the pressure of the second vapor refrigerant flow 148 and the target pressure. Similarly, because the second economizer 146 provides additional pressure reduction of the first liquid refrigerant flow 144 from the first economizer 140, the pressure of the second vapor refrigerant flow 148 may be less than the pressure of the first vapor refrigerant flow 142. As such, the pressure differential between the pressure of the second vapor refrigerant flow 148 and the target pressure may be greater than a pressure differential between the pressure of the first vapor refrigerant flow 142 and the target pressure. For this reason, an amount of pressurization provided by the third auxiliary compressor 164 for the third vapor refrigerant flow 154 may be greater than an amount of pressurization provided by the second auxiliary compressor 162 for the second vapor refrigerant flow 148, and the amount of pressurization provided by the second auxiliary compressor 162 for the second vapor refrigerant flow 148 may be greater than an amount of pressurization provided by the first auxiliary compressor 160 for the first vapor refrigerant flow 142.

[0048] Additionally, an amount of the vapor refrigerant flows 142, 148, 154 provided by the economizer system 104 may be different from one another. For example, the mass flow of the vapor refrigerant flows 142, 148, 154 may be based on the pressure within the condenser 34 and/or within each of the economizers 140, 146, 152, and the volume flow of the vapor refrigerant flows 142, 148, 154 may be based on the vapor density of the vapor density at the respective pressures within the economizers 140, 146, 152. Indeed, the amount of the first vapor refrigerant flow 142 provided by the first economizer 140 may be greater or smaller than the amount of the second vapor refrigerant flow 148 provided by the second economizer 146, and the amount of the second vapor refrigerant 148 provided by the second economizer 146 may be greater or smaller than the amount of the third vapor refrigerant flow 154 provided by the third economizer 152. In additional or alternative embodiments, the amount of vapor refrigerant flows 142, 148, 154 provided by the economizer system 104 may be substantially similar to one another.

[0049] Embodiments or specifications of the auxiliary compressors 160, 162, 164 may be selected based on the respective amounts of pressurization to be provided by the auxiliary compressors 160, 162, 164 and/or the respective amounts of the vapor refrigerant flows 142, 148, 154 received by the auxiliary compressors 160, 162, 164. Thus, each auxiliary compressor 160, 162, 164 may have a different embodiment (e g., a different size, a different type). As an example, the first auxiliary compressor 160 may be relatively larger or smaller than the second auxiliary compressor 162 and/or the third auxiliary compressor 164 to enable receipt and pressurization of the relatively larger or smaller amount, respectively, of the first vapor refrigerant flow 142, and/or the third auxiliary compressor 164 may be relatively larger or smaller than the first auxiliary compressor 160 and/or the second auxiliary compressor 162 to enable receipt and pressurization of the relatively larger or smaller amount, respectively, of the third vapor refrigerant flow 154. In additional or alternative embodiments, such as embodiments in which the amount of vapor refrigerant flows 142, 148, 154 are similar to one another, the auxiliary compressors 160, 162, 164 may be of the same or similar embodiments.

[0050] Each auxiliary compressor 160, 162, 164 may, for instance, include an oil-free compressor to avoid increasing a cost and/or complexity associated with management of oil and/or lubricant circulated through the vapor compression system 100 (e.g., for cooling of the auxiliary compressors 160, 162, 164). Additionally or alternatively, the auxiliary compressors 160, 162, 164 may include a scroll compressor, a centrifugal compressor, a reciprocating compressor, or any other suitable compressor type. In any case, each auxiliary compressor 160, 162, 164 may be less costly and/or may occupy a smaller physical footprint as compared to the primary compressor 102.

[0051] Additionally, the vapor compression system 100 may include a conduit system 174 configured to control flow of the vapor refrigerant flows 142, 148, 154 to the auxiliary compressor system 106. As an example, the conduit system 174 may be operated to enable a desirable or suitable flow (e.g., a target flow rate, a target flow velocity) of the vapor refrigerant flows 142, 148, 154 to the auxiliary compressors 160, 162, 164. For instance, a first valve 176 of the conduit system 174 may control a flow rate of the first vapor refrigerant flow 142 from the first economizer 140 to the first auxiliary compressor 160, a second valve 178 of the conduit system 174 may control a flow rate of the second vapor refrigerant flow 148 from the second economizer 146 to the second auxiliary compressor 162, and a third valve 180 of the conduit system 174 may control a flow rate of the third vapor refrigerant flow 154 from the third economizer 152 to the third auxiliary compressor 164. The opening of the valves 176, 178, 180 may be adjusted to direct the vapor refrigerant flows 142, 148, 154 in a suitable manner to the auxiliary compressors 160, 162, 164 (e.g., at flows based on design specifications of the auxiliary compressors 160, 162, 164), respectively, to enable efficient and/or desirable operation of the auxiliary compressors 160, 162, 164.

[0052] The vapor compression system 100 may also include a control system 182 (e.g., the control panel 40 configured to operate the primary compressor 102, a control system separate from the control panel 40), which may be an automation controller and/or an electronic controller. The control system 182 may be configured to control operation of various components of the vapor compression system 100, such as the economizer system 104, the auxiliary compressor system 106, and/or the conduit system 174. For example, the control system 182 may include a memory 184 and processing circuitry 186. The memory 184 may include volatile memory, such as random-access 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 vapor compression system 100. The processing circuitry 186 may be configured to execute such instructions stored in the memory 184. As an example, the processing circuitry 186 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.

[0053] As an example, the control system 182 may be configured to operate each of the economizers 140, 146, 152 to adjust the respective pressure reductions provided by the economizers 140, 146, 152. As another example, the control system 182 may be configured to operate each of the auxiliary compressors 160, 162, 164, such as by adjusting a stage, a speed, a frequency, and/or any other regulation system (e.g., mechanical system) to provide desirable pressurization of the respective vapor refrigerant flows 142, 148, 154, such as to the target pressure. As a further example, the control system 182 may be configured to operate each of the valves 176, 178, 180, such as by adjusting the respective openings of the valves 176, 178, 180, to adjust the flow rates of the vapor refrigerant flows 142, 148, 154 to the respective auxiliary compressors 160, 162, 164. Thus, the control system 182 may adjust operation of various components of the vapor compression system 100.

[0054] Although the economizer system 104 of the illustrated vapor compression system 100 includes three economizers 140, 146, 152, the auxiliary compressor system 106 of the illustrated vapor compression system 100 includes three auxiliary compressors 160, 162, 164, and the conduit system 174 of the illustrated vapor compression system 100 includes three valves 176, 178, 180, in additional or alternative embodiments, the economizer system 104 may include any suitable number of economizers 140, 146, 152, the auxiliary compressor system 106 may include any suitable number of auxiliary compressors 160, 162, 164, and/or the conduit system 174 may include any suitable number of valves 176, 178, 180. The quantity of economizers 140, 146, 152, the quantity of auxiliary compressors 160, 162, 164, and/or the quantity of valves 176, 178, 180 may correspond to or be equal to one another in some embodiments. For example, the vapor compression system 100 may include two economizers 140, 146, 152, two auxiliary compressors 160, 162, 164, and two valves 176, 178, 180, the vapor compression system 100 may include four economizers 140, 146, 152, four auxiliary compressors 160, 162, 164, and four valves 176, 178, 180, and so forth.

[0055] FIG. 7 is a schematic of an embodiment of the vapor compression system 100 that includes the economizer system 104 and the auxiliary compressor system 106. In the illustrated embodiment, the economizer system 104 includes the first economizer 140 configured to direct the first vapor refrigerant flow 142 to the auxiliary compressor system 106 and the first liquid refrigerant flow 144 to the second economizer 146, as well as the second economizer 146 configured to direct the second vapor refrigerant flow 148 to the auxiliary compressor system 106 and the second liquid refrigerant flow 150 to the evaporator 38. The auxiliary compressor system 106 includes the first auxiliary compressor 160 configured to receive the first vapor refrigerant flow 142 from the first economizer 140, as well as the second auxiliary compressor configured to receive the second vapor refrigerant flow 148 from the second economizer 146. The conduit system 174 of the vapor compression system 100 includes the first valve 176 configured to control flow of the first vapor refrigerant flow 142 to the first auxiliary compressor 160, as well as the second valve 178 configured to control flow of the second vapor refrigerant flow 148 to the second auxiliary compressor 162.

[0056] The auxiliary compressors 160, 162 may be in a series flow arrangement. For example, the second auxiliary compressor 162 may pressurize the second vapor refrigerant flow 148 received from the second economizer 146 to provide the second pressurized vapor refrigerant flow 168 as discharge toward the first auxiliary compressor 160. The second pressurized vapor refrigerant flow 168 may combine with the first vapor refrigerant flow 142 directed from the first economizer 140 for intake by the first auxiliary compressor 160. For this reason, the second auxiliary compressor 162 may increase the pressure of the second vapor refrigerant flow 148 toward the pressure of the first vapor refrigerant flow 142 directed from the first economizer 140 to enable the second pressurized vapor refrigerant flow 168 from the second auxiliary compressor 162 and the first vapor refrigerant flow 142 from the first economizer 140 to flow more readily to the first auxiliary compressor 160. For instance, the second pressurized vapor refrigerant flow 168 and the first vapor refrigerant flow 142 that are at substantially the same pressure may flow toward the first auxiliary compressor 160 instead of, for example, back flowing toward the first economizer 140 and/or toward the second auxiliary compressor 162.

[0057] The first auxiliary compressor 160 may pressurize the second pressurized vapor refrigerant flow 168 and the first vapor refrigerant flow 142 to provide a combined pressurized vapor refrigerant flow 220 for discharge toward the condenser 34. Thus, the second vapor refrigerant flow 148 may be pressurized by the second auxiliary compressor 162 and further pressurized by the first auxiliary compressor 160. In this manner, the auxiliary compressor system 106 may provide multi-stage compression of the second vapor refrigerant flow 148 (e.g., the second auxiliary compressor 162 may be a first compressor stage providing initial pressurization, and the first auxiliary compressor 160 may be a second compressor stage providing further pressurization). The first auxiliary compressor 160 may increase the pressure of the second pressurized vapor refrigerant flow 168 and the first vapor refrigerant flow 142 toward that of the primary refrigerant flow 159 to facilitate flow of the combined pressurized vapor refrigerant flow 220 from the auxiliary compressor system 106 and the primary refrigerant flow 159 from the primary compressor 102 to and/or through the condenser 34.

[0058] The first auxiliary compressor 160 and the second auxiliary compressor 162 may be of different embodiments. For example, the embodiment of the first auxiliary compressor 160 may be selected to enable receipt and pressurization of both the first vapor refrigerant flow 142 and the second pressurized vapor refrigerant flow 168. Thus, the embodiment of the first auxiliary compressor 160 may enable increased refrigerant capacity or flow therethrough as compared to the embodiment of the second auxiliary compressor 162, which may pressurize the second vapor refrigerant flow 148 and not the first vapor refrigerant flow 142.

[0059] In some embodiments, the auxiliary compressor system 106 may include more than two auxiliary compressors 160, 162 in series with one another. For example, in embodiments in which the economizer system 104 includes the third economizer 152 configured to receive the second liquid refrigerant flow 150 from the second economizer 146, the auxiliary compressor system 106 may include the third auxiliary compressor 164 configured to receive and pressurize the third vapor refrigerant flow 154 from the third economizer 152 to provide the third pressurized vapor refrigerant flow 170. The third pressurized vapor refrigerant flow 170 may be discharged toward the second auxiliary compressor 162 and then toward the first auxiliary compressor 160 for further staged pressurization. Thus, in the series flow arrangement, certain vapor refrigerant flows from the economizer system 104 may be pressurized by multiple auxiliary compressors.

[0060] FIG. 8 is a schematic of an embodiment of the vapor compression system 100 that includes the economizer system 104 and the auxiliary compressor system 106. In the illustrated embodiment, the economizer system 104 includes the first economizer 140, which may direct the first liquid refrigerant flow 144 to the evaporator 38. The first economizer 140 may also direct a first vapor refrigerant flow 250 and a second vapor refrigerant flow 252 toward the auxiliary compressor system 106, which may include the first auxiliary compressor 160 and the second auxiliary compressor 162. For example, the first economizer 140 may produce vapor refrigerant by reducing the pressure of the refrigerant received from the condenser 34, and the first economizer 140 may apportion the produced vapor refrigerant to direct the first vapor refrigerant flow 250 toward the first auxiliary compressor 160 and the second vapor refrigerant flow 252 toward the second auxiliary compressor 162. For instance, the conduit system 174 may include the first valve 176 configured to control flow of the first vapor refrigerant flow 250 to the first auxiliary compressor 160, as well as the second valve 178 configured to control flow of the second vapor refrigerant flow 252 to the second auxiliary compressor 162. The control system 182 may adjust the openings of the valves 176, 178 to control flow of the vapor refrigerant flows 250, 252 to the auxiliary compressors 160, 162.

[0061] The auxiliary compressors 160, 162 may be in a parallel flow arrangement. That is, the auxiliary compressors 160, 162 may pressurize the respective vapor refrigerant flows 250, 252 for discharge toward the condenser 34. As an example, the first auxiliary compressor 160 may pressurize the first vapor refrigerant flow 250 to provide a first pressurized vapor refrigerant flow 254 and discharge the first pressurized vapor refrigerant flow 254 toward the condenser 34. The second auxiliary compressor 162 may pressurize the second vapor refrigerant flow 252 to provide a second pressurized vapor refrigerant flow 256 and discharge the second pressurized vapor refrigerant flow 256 toward the condenser 34. The first pressurized vapor refrigerant flow 254 and the second pressurized vapor refrigerant flow 256 may combine as a combined pressurized vapor refrigerant flow 258 for intake by the condenser 34. Thus, the first pressurized vapor refrigerant flow 254 may bypass flow through the second auxiliary compressor 162, and/or the second pressurized vapor refrigerant flow 256 may bypass flow through the first auxiliary compressor 160. The auxiliary compressors 160, 162 may increase the pressure of the respective vapor refrigerant flows 250, 252 toward the pressure of the primary refrigerant flow 159 discharged by the primary compressor 102 to facilitate directing the primary refrigerant flow 159, the first pressurized vapor refrigerant flow 254, and the second pressurized vapor refrigerant flow 256 to and/or through the condenser 34.

[0062] In additional or alternative embodiments, the vapor refrigerant provided by the first economizer 140 may be apportioned to more than two auxiliary compressors 160, 162. For example, a third vapor refrigerant flow may be directed from the first economizer 140 toward a third auxiliary compressor for pressurization and discharge toward the condenser 34.

[0063] FIG. 9 is a schematic of an embodiment of the vapor compression system 100 that includes the economizer system 104 and the auxiliary compressor system 106. In the illustrated embodiment, the economizer system 104 includes the first economizer 140 and the second economizer 146. The first economizer 140 may be configured to direct the first vapor refrigerant flow 142 to the auxiliary compressor system 106 and the first liquid refrigerant flow 144 to the second economizer 146. The second economizer 146 may be configured to direct the second vapor refrigerant flow 148 to the auxiliary compressor system 106 and the second liquid refrigerant flow 150 to the evaporator 38. The auxiliary compressor system 106 includes the first auxiliary compressor 160, the second auxiliary compressor 162, and the third auxiliary compressor 164. The first auxiliary compressor 160 may be configured to receive the first vapor refrigerant flow 142 from the first economizer 140, and the second auxiliary compressor 162 may be configured to receive the second vapor refrigerant flow 148 from the second economizer 146. The conduit system 174 includes the first valve 176 configured to control flow of the first vapor refrigerant flow 142 to the first auxiliary compressor 160, as well as the second valve 178 configured to control flow of the second vapor refrigerant flow 148 to the second auxiliary compressor 162.

[0064] The first auxiliary compressor 160 may pressurize the first vapor refrigerant flow 142 to provide the first pressurized vapor refrigerant flow 166 for discharge toward the condenser 34. For example, the first vapor refrigerant flow 142 may bypass flow through the second auxiliary compressor 162 and the third auxiliary compressor 164. The second auxiliary compressor 162 may pressurize the second vapor refrigerant flow 148 to provide the second pressurized vapor refrigerant flow 168, and the second auxiliary compressor 162 may discharge the second pressurized vapor refrigerant flow 168 toward the third auxiliary compressor 164. The third auxiliary compressor 164 may further pressurize the second pressurized vapor refrigerant flow 168 to provide a third pressurized vapor refrigerant flow 280 for discharge toward the condenser 34. Thus, the third pressurized vapor refrigerant flow 280 may bypass flow through the first auxiliary compressor 160. The first pressurized vapor refrigerant flow 166 discharged by the first auxiliary compressor 160 and the third pressurized vapor refrigerant flow 280 discharged by the third auxiliary compressor 164 may combine to form a combined pressurized vapor refrigerant flow 282 for intake by the condenser 34. The first auxiliary compressor 160 may increase the pressure of the first vapor refrigerant flow 142 and the third auxiliary compressor 164 may increase the pressure of the second vapor refrigerant flow 168 to approximately the same pressure, such as a pressure substantially equal to the pressure of the primary refrigerant flow 159.

[0065] In this manner, the second auxiliary compressor 162 and the third auxiliary compressor 164 may be in a series flow arrangement with one another, and the first auxiliary compressor 160 may be in a parallel flow arrangement with respect to the second auxiliary compressor 162 and the third auxiliary compressor 164. Indeed, the second auxiliary compressor 162 and the third auxiliary compressor 164 may operate as a multistage compressor for the second vapor refrigerant flow 148 in which the second vapor refrigerant flow 148 may be pressurized by the second auxiliary compressor 162 and further pressurized by the third auxiliary compressor 164 to achieve a desirable pressure of the third pressurized vapor refrigerant flow 280 for discharge toward the condenser 34.

[0066] Although the illustrated auxiliary compressor system 106 includes the second auxiliary compressor 162 and the third auxiliary compressor 164 in a series flow arrangement, in additional or alternative embodiments, the first auxiliary compressor 160 may be in a series flow arrangement with an additional auxiliary compressor (e.g., a fourth auxiliary compressor). In further embodiments, more than two auxiliary compressors (e.g., the second auxiliary compressor 162, the third auxiliary compressor 164, and a fourth auxiliary compressor) may be in a series flow arrangement with one another, while also in a parallel series flow arrangement with another auxiliary compressor (e.g., the first auxiliary compressor 160).

[0067] FIG. 10 is a schematic of an embodiment of the vapor compression system 100 that includes the economizer system 104 and the auxiliary compressor system 106. Tn the illustrated embodiment, the economizer system 104 includes the first economizer 140 configured to direct the first vapor refrigerant flow 142 to the auxiliary compressor system 106 and the first liquid refrigerant flow 144 to the second economizer 146, as well as the second economizer 146 configured to direct the second vapor refrigerant flow 148 to the auxiliary compressor system 106 and the second liquid refrigerant flow 150 to the evaporator 38. The auxiliary compressor system 106 may include the first auxiliary compressor 160, the second auxiliary compressor 162, and the third auxiliary compressor 164.

[0068] The first auxiliary compressor 160 may receive and pressurize the first vapor refrigerant flow 142 to provide the first pressurized vapor refrigerant flow 166, and the second auxiliary compressor 162 may receive and pressurize the second vapor refrigerant flow 148 to provide the second pressurized vapor refrigerant flow 168. The first pressurized vapor refrigerant flow 166 and the second pressurized vapor refrigerant flow 168 may combine for intake by the third auxiliary compressor 164. For this reason, the pressure of the first pressurized vapor refrigerant flow 166, as effectuated by the first auxiliary compressor 106, and the second pressurized vapor refrigerant flow 168, as effectuated by the second auxiliary compressor 162, may be substantially equal to one another to facilitate flow toward the third auxiliary compressor 164. The third auxiliary compressor 164 may pressurize the first pressurized vapor refrigerant flow 166 and the second pressurized vapor refrigerant flow 168 to provide a combined pressurized vapor refrigerant flow 310 for discharge toward the condenser 34. For example, the third auxiliary compressor 164 may further increase the pressure of the first pressurized vapor refrigerant flow 166 and the second pressurized vapor refrigerant flow 168 toward that of the primary refrigerant flow 159.

[0069] As such, the first auxiliary compressor 160 and the second auxiliary compressor 162 may be in a parallel flow arrangement with one another, while each of the first auxiliary compressor 160 and the second auxiliary compressor 162 may be in a series flow arrangement with respect to the third auxiliary compressor 164 Thus, each of the auxiliary compressors 160, 162, 164 may operate as one of a plurality of stages for pressurizing the first vapor refrigerant flow 142 and/or the second vapor refrigerant flow 148. For example, the first auxiliary compressor 160 may operate as a first stage for providing initial pressurization of the first vapor refrigerant flow 142, and the second auxiliary compressor 162 may operate in parallel as a first stage for providing initial pressurization of the second vapor refrigerant flow 148. The third auxiliary compressor 164 may operate as a second stage for providing additional pressurization of the first vapor refrigerant flow 142 and the second vapor refrigerant flow 148 to achieve a desirable pressure of the combined pressurized vapor refrigerant flow 310 for discharge toward the condenser 34.

[0070] In additional or alternative embodiments, the auxiliary compressor system 106 may include an additional auxiliary compressor in a series flow arrangement. For instance, a fourth auxiliary compressor may provide further pressurization of the refrigerant discharged by the third auxiliary compressor 164. As an example, the fourth auxiliary compressor may pressurize the combined pressurized vapor refrigerant flow 310 discharged by the third auxiliary compressor 164. In further embodiments, the auxiliary compressor system 106 may include a fourth auxiliary compressor in a parallel flow arrangement. For example, the economizer system 104 may include the third economizer 152, the fourth auxiliary compressor may receive the third vapor refrigerant flow 154 from the third economizer 152, pressurize the third vapor refrigerant flow 154 to provide the third pressurized vapor refrigerant flow 170, and discharge the third pressurized vapor refrigerant flow 170 toward any of the other auxiliary compressors (e.g., the second auxiliary compressor 162, the third auxiliary compressor 164) that are in the series flow arrangement.

[0071] FIG. 11 is a schematic of an embodiment of the vapor compression system 100 that includes the economizer system 104 and the auxiliary compressor system 106. In the illustrated embodiment, the economizer system 104 includes the first economizer 140, which may direct the first liquid refrigerant flow 144 to the evaporator 38 and apportion the first vapor refrigerant flow 250 and the second vapor refrigerant flow 252 toward the auxiliary compressor system 106. The auxiliary compressor system 106 may include the first auxiliary compressor 160, the second auxiliary compressor 162, and the third auxiliary compressor 164. The first auxiliary compressor 160 may receive and pressurize the first vapor refrigerant flow 250 to provide the first pressurized vapor refrigerant flow 254, and the second auxiliary compressor 162 may receive and pressurize the second vapor refrigerant flow 252 to provide the second pressurized vapor refrigerant flow 256. The first auxiliary compressor 160 and the second auxiliary compressor 162 may discharge the first pressurized vapor refrigerant flow 254 and the second vapor refrigerant flow 256, respectively, toward the third auxiliary compressor 164. For example, the first pressurized vapor refrigerant flow 254 and the second vapor refrigerant flow 256 may combine for intake by the third auxiliary compressor 164. For this reason, the pressure of the first pressurized vapor refrigerant flow 254, as effectuated by the first auxiliary compressor 160, and the pressure of the second vapor refrigerant flow 256, as effectuated by the second auxiliary compressor 162, may be substantially equal to one another to facilitate flow to the third auxiliary compressor 164.

[0072] The third auxiliary compressor 164 may pressurize the first pressurized vapor refrigerant flow 254 and the second pressurized vapor refrigerant flow 256 to provide a combined pressurized vapor refrigerant flow 340. As an example, the third auxiliary compressor 164 may increase the pressure of the first pressurized vapor refrigerant flow 254 and the second pressurized vapor refrigerant flow 256 toward the pressure of the primary refrigerant flow 159 to facilitate flow of the primary refrigerant flow 159 and the combined pressurized vapor refrigerant flow 340 to and/or through the condenser 34. In this manner, the first auxiliary compressor 160 and the second auxiliary compressor 162 may be in a parallel flow arrangement with one another, while each of the first auxiliary compressor 160 and the second auxiliary compressor 162 may be in a series flow arrangement with respect to the third auxiliary compressor 164. That is, each of the first auxiliary compressor 160 and the second auxiliary compressor 162 may operate as a first stage for pressurizing the vapor refrigerant (e.g., the first vapor refrigerant flow 250, the second vapor refrigerant flow 252) from the first economizer 140, and the third auxiliary compressor 164 may operate as a second stage for providing additional pressurization of the vapor refrigerant from the first economizer 140.

[0073] The auxiliary compressor system 106 may also include any other suitable number of auxiliary compressors in the series flow arrangement (e.g., three or more stages of auxiliary compressors) and/or in the parallel flow arrangement. Indeed, an auxiliary compressor (e.g., the first auxiliary compressor 160) that is a part of the parallel flow arrangement may discharge pressurized refrigerant toward any of the auxiliary compressors in the series flow arrangement.

[0074] FIG. 12 is a schematic of an embodiment of the vapor compression system 100 that includes the economizer system 104 and the auxiliary compressor system 106. In the illustrated embodiment, the economizer system 104 includes the first economizer 140, which may direct the first liquid refrigerant flow 144 toward the second economizer 146, the first vapor refrigerant flow 250 toward the auxiliary compressor system 106, and the second vapor refrigerant flow 252 toward the auxiliary compressor system 106. The second economizer 146 may direct the second liquid refrigerant flow 150 toward the evaporator 38 and a third vapor refrigerant flow 370 toward the auxiliary compressor system 106. The auxiliary compressor system 106 may include the first auxiliary compressor 160, the second auxiliary compressor 162, and the third auxiliary compressor 164. The first auxiliary compressor 160 may receive and pressurize the first vapor refrigerant flow 250 to provide the first pressurized vapor refrigerant flow 254 for discharge toward the condenser 34, and the second auxiliary compressor 162 may receive and pressurize the second vapor refrigerant flow 252 to provide the second pressurized vapor refrigerant flow 256 for discharge toward the condenser 34. The third auxiliary compressor 164 may receive and pressurize the third vapor refrigerant flow 370 to provide a third pressurized vapor refrigerant flow 372 for discharge toward the condenser 34. The first pressurized vapor refrigerant flow 254, the second pressurized vapor refrigerant flow 256, and/or the third pressurized vapor refrigerant flow 372 may combine to provide a combined pressurized vapor refrigerant flow 374 for intake by the condenser 34. The conduit system 174 may include the first valve 176 configured to control flow of the first vapor refrigerant flow 250 to the first auxiliary compressor 160, the second valve 178 configured to control flow of the second vapor refrigerant flow 252 to the second auxiliary compressor 162, and a third valve 376 configured to control flow of the third vapor refrigerant flow 370 to the third auxiliary compressor 164.

[0075] The auxiliary compressors 160, 162, 164 may pressurize the vapor refrigerant flows 250, 252, 370 toward the pressure of the primary refrigerant flow 159. Moreover, the vapor refrigerant flow provided by the economizers 140, 146 may be different from one another. Thus, a total amount of overall vapor refrigerant flow (e.g., a combination of the first refrigerant flow 250 and the second refrigerant flow 252) provided by the first economizer 140 may be greater or smaller than the amount of the third vapor refrigerant flow 370 provided by the second economizer 146. Additionally, because the total amount of overall vapor refrigerant flow from the first economizer 140 is distributed as the first vapor refrigerant flow 250 and the second vapor refrigerant flow 252, the amount of the first vapor refrigerant flow 250 and/or the second vapor refrigerant flow may be significantly less than the total amount of overall vapor refrigerant flow. For example, although the total amount of overall vapor refrigerant flow may be greater than the amount of the third vapor refrigerant flow 370, the amount of the first vapor refrigerant flow 250 and the second vapor refrigerant flow 252 may be approximately equal to one another and/or to the third vapor refrigerant flow 370. Thus, the embodiments of the first auxiliary compressor 160 and/or the second auxiliary compressor 162 may be selected to enable receipt and pressurization of a relatively smaller first vapor refrigerant flow 250 and a relatively smaller second vapor refrigerant flow 252, respectively, and instead of, as an example, a relatively larger total amount of overall vapor refrigerant flow.

|0076| FIGS. 13-16 are graphical illustrations of vapor compression cycles for different vapor compression systems, which correspond to various possible configurations of the present disclosure. For example, each of FIGS. 13-16 includes an x-axis 302 corresponding to enthalpy (“H” or “h”) and a y-axis 304 corresponding to log pressure (“p”). The graph 300 of FIG. 13 corresponds to an embodiment in which the cycle includes at least a primary compressor, two economizer stages, and two auxiliary compressor stages corresponding to the two economizer stages and in parallel flow. The graph 400 of FIG. 14 corresponds to an embodiment in which the cycle includes at least a primary compressor, two economizer stages, and two auxiliary compressor stages corresponding to the two economizer stages, where the two auxiliary compressor stages are in series flow (e g., similar to or the same as the embodiment illustrated in FIG. 7).

[0077] The graph 500 of FIG. 15 corresponds to an embodiment in which the cycle includes at least a primary compressor, an economizer stage, and two auxiliary compressor stages corresponding to the economizer stage, where the two auxiliary compressor stages are in parallel flow. That is, the graph 500 of FIG. 15 may correspond to the embodiment illustrated in FIG. 8, which includes the above-described features, and/or the embodiment illustrated in FIG. 12, which includes the above-described features in addition to a second economizer stage and a third auxiliary compressor stage corresponding to the second economizer stage, where the first, second, and third auxiliary compressor stages are in parallel flow. The graph 600 of FIG. 16 corresponds to an embodiment in which the cycles includes at least a primary compressor, first and second economizer stages, first and second auxiliary compressor stages corresponding to the first and second economizer stages and in series flow (e.g., where the first auxiliary compressor stage is connected between the first economizer stage, such as a low pressure economizer, and the second economizer stage, such as a high pressure economizer, and where the second auxiliary compressor stage is connected between the second economizer stage to the condenser), and a third compressor stage in parallel flow connected from the first economizer stage to the condenser.

[0078] 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. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be 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.

[0079] 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: an economizer system configured to reduce a pressure of a first portion of a refrigerant; an auxiliary compressor system configured to receive the first portion of the refrigerant from the economizer system, wherein the auxiliary compressor system comprises a first auxiliary compressor and a second auxiliary compressor; a primary compressor; and a condenser configured to receive the first portion of the refrigerant from the auxiliary compressor system and a second portion of the refrigerant from the primary compressor.

2. The HVAC&R system of claim 1, comprising an evaporator configured to supply the second portion of the refrigerant to the primary compressor.

3. The HVAC&R system of claim 2, wherein the evaporator is configured to receive the second portion of the refrigerant in liquid form from the economizer system, and the auxiliary compressor system is configured to receive the first portion of the refrigerant in vapor form from the economizer system.

4. The HVAC&R system of claim 1, wherein the first auxiliary compressor is disposed in series with the second auxiliary compressor with respect to a flow of the first portion of the refrigerant, such that the first auxiliary compressor is configured to receive the first portion of the refrigerant from the economizer system and the second auxiliary compressor is configured to receive the first portion of the refrigerant from the first auxiliary compressor.

5. The HVAC&R system of claim 1, wherein the first auxiliary compressor is disposed in parallel with the second auxiliary compressor with respect to a flow of the first portion of the refrigerant, such that the first auxiliary compressor is configured to receive a first amount of the first portion of the refrigerant from the economizer system and the second auxiliary compressor is configured to receive a second amount of the first portion of the refrigerant from the economizer system.

6. The HVAC&R system of claim 5, wherein the economizer system comprises: a first economizer, wherein the first auxiliary compressor is configured to receive the first amount of the first portion of the refrigerant from the first economizer; and a second economizer, wherein the second auxiliary compressor is configured to receive the second amount of the first portion of the refrigerant from the second economizer.

7. The HVAC&R system of claim 1, wherein the auxiliary compressor system comprises a third auxiliary compressor.

8. A heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system, comprising: an economizer system configured to reduce a pressure of a refrigerant to provide a first vapor refrigerant flow and a second vapor refrigerant flow; and an auxiliary compressor system comprising: a first auxiliary compressor configured to receive the first vapor refrigerant flow from the economizer system and pressurize the first vapor refrigerant flow to provide a first pressurized vapor refrigerant flow; and a second auxiliary compressor configured to receive the second vapor refrigerant flow from the economizer system and pressurize the second vapor refrigerant flow to provide a second pressurized vapor refrigerant flow, wherein the auxiliary compressor system is configured to discharge a combined vapor refrigerant flow comprising the first pressurized vapor refrigerant flow and the second pressurized vapor refrigerant flow toward a condenser of the HVAC&R system.

9. The HVAC&R system of claim 8, wherein the first auxiliary compressor is configured to discharge the first pressurized vapor refrigerant flow toward the condenser as a part of the combined vapor refrigerant flow, and the second auxiliary compressor is configured to discharge the second pressurized vapor refrigerant flow toward the condenser as an additional part of the combined vapor refrigerant flow.

10. The HVAC&R system of claim 8, wherein the second auxiliary compressor is configured to discharge the second pressurized vapor refrigerant flow toward the first auxiliary compressor, and the first auxiliary compressor is configured to pressurize the first vapor refrigerant flow and the second pressurized vapor refrigerant flow to provide the combined vapor refrigerant flow comprising the first pressurized vapor refrigerant flow and the second pressurized vapor refrigerant flow for discharge toward the condenser.

11. The HVAC&R system of claim 8, wherein the economizer system comprises: a first economizer configured to receive the refrigerant from the condenser and separate the refrigerant into a first liquid refrigerant flow and the first vapor refrigerant flow; and a second economizer configured to receive the first liquid refrigerant flow and separate the first liquid refrigerant flow into a second liquid refrigerant flow and the second vapor refrigerant flow.

12. The HVAC&R system of claim 8, comprising a third auxiliary compressor, wherein the first auxiliary compressor is configured to discharge the first pressurized vapor refrigerant flow toward the condenser as a part of the combined vapor refrigerant flow, the second auxiliary compressor is configured to discharge the second pressurized vapor refrigerant flow toward the third auxiliary compressor, and the third auxiliary compressor is configured to pressurize the second pressurized vapor refrigerant flow for discharge toward the condenser as another part of the combined vapor refrigerant flow.

13. The HVAC&R system of claim 8, comprising a third auxiliary compressor, wherein the first auxiliary compressor is configured to discharge the first pressurized vapor refrigerant flow toward the third auxiliary compressor, the second auxiliary compressor is configured to discharge the second pressurized vapor refrigerant flow toward the third auxiliary compressor, and the third auxiliary compressor is configured to pressurize the first pressurized vapor refrigerant flow and the second pressurized vapor refrigerant flow to provide the combined vapor refrigerant flow for discharge toward the condenser.

14. The HVAC&R system of claim 8, wherein the economizer system comprises an economizer configured to receive the refrigerant from the condenser and separate the refrigerant into liquid refrigerant and vapor refrigerant, and the economizer system is configured to apportion the vapor refrigerant as the first vapor refrigerant flow and the second vapor refrigerant flow.

15. The HVAC&R system of claim 8, comprising: an evaporator configured to receive a refrigerant flow from the economizer system and discharge the refrigerant flow from an outlet of the evaporator; and a primary compressor configured to operate to pressurize the refrigerant flow from the outlet of the evaporator to a target pressure for discharge toward the condenser.

16. The HVAC&R system of claim 15, wherein the first auxiliary compressor is configured to pressurize the first vapor refrigerant flow and the second auxiliary compressor is configured to pressurize the second vapor refrigerant flow to adjust a pressure of the combined vapor refrigerant flow toward the target pressure.

17. The HVAC&R system of claim 8, comprising a first valve and a second valve, wherein the first valve is configured to control flow of the first vapor refrigerant flow from the economizer system to the first auxiliary compressor, and the second valve is configured to control flow of the second vapor refrigerant flow from the economizer system to the second auxiliary compressor.

18. A compression system of a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system, the compression system comprising: an auxiliary compressor system configured to receive a first portion of a refrigerant from an economizer system of the HVAC&R system, the auxiliary compression system comprising a first auxiliary compressor and a second auxiliary compressor; and a primary compressor configured to receive a second portion of the refrigerant from an evaporator of the HVAC&R system.

19. The compression system of claim 18, wherein: the auxiliary compressor system is configured to output the first portion of the refrigerant toward a condenser; and the primary compressor is configured to output the second portion of the refrigerant toward the condenser.

20. The compression system of claim 18, wherein: the first auxiliary compressor is disposed in series with the second auxiliary compressor with respect to a flow of the first portion of the refrigerant, such that the second auxiliary compressor is configured to receive the first portion of the refrigerant from the first auxiliary compressor; or the first auxiliary compressor is disposed in parallel with the second auxiliary compressor with respect to the flow of the first portion of the refrigerant, such that the first auxiliary compressor is configured to receive a first amount of the first portion of the refrigerant from an economizer system and the second auxiliary compressor is configured to receive second amount of the first portion of the refrigerant from the economizer system.