KR20250037548A - Compressor systems for heating, ventilation, air conditioning and refrigeration systems - Google Patents

Abstract

A heating, ventilation, air conditioning and refrigeration system configured to circulate a working fluid includes an economizer system and a compressor system. A first economizer of the economizer system is configured to reduce a first working fluid pressure to provide a first vapor working fluid flow, and a second economizer of the economizer system is configured to reduce a second working fluid pressure within 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 through a second inlet, and the first compressor stage is configured to receive an additional working fluid flow separate from the second vapor working fluid flow through the first inlet. A second compressor stage of the compressor system is configured to receive the first vapor working fluid flow from the first economizer through a third inlet.

Description

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

Cross-reference to related applications

This application claims priority to U.S. Provisional Application No. 63/390,004, filed July 18, 2022, entitled COMPRESSOR SYSTEM FOR FOR HEATING, VENTILATION, AIR CONDITIONING & REFRIGERATION SYSTEM, which is incorporated by reference herein in its entirety for all purposes.

This section is intended to introduce the reader to various aspects of the field that may be related to the various aspects of the present disclosure described below. It is believed that this discussion will be helpful in providing the reader with background information that will facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that this disclosure should be read in this light, and not as an admission of prior art.

A chiller system, or vapor compression system, utilizes a working fluid (e.g., a refrigerant) that changes phase between vapor, liquid, or a combination thereof in response to exposure to different temperatures and pressures within the components of the chiller system. The chiller system can place the working fluid in heat exchange relationship with a cooling fluid (e.g., water) and deliver the cooling fluid to a conditioned environment and/or conditioning equipment serviced by the chiller system. In some embodiments, the chiller system can include an economizer configured to improve the efficiency of the chiller system. For example, a first heat exchanger (e.g., a condenser) can cool the working fluid and pass the cooled working fluid to the economizer, which can separate the working fluid into a liquid working fluid and a vapor working fluid. The economizer can pass the liquid working fluid to a second heat exchanger (e.g., an evaporator) configured to place the working fluid in heat exchange relationship with the cooling fluid. The economizer can pass the vapor working fluid to a compressor system for pressurization. Unfortunately, conventional chiller systems that include economizers can be expensive or operate inefficiently.

A summary of specific embodiments disclosed herein is provided below. It should be understood that these aspects are provided merely to provide the reader with a brief summary of these specific embodiments and that these aspects are not intended to limit the scope of the disclosure. Indeed, the disclosure may include various aspects not specifically set forth below.

In one embodiment, a heating, ventilation, air conditioning, and/or cooling system configured to circulate a working fluid comprises an economizer system and a compressor system. A first economizer of the economizer system is configured to reduce a first working fluid pressure to provide a first vapor working fluid flow, and a second economizer of the economizer system is configured to reduce a second working fluid pressure within 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 through a second inlet, and the first compressor stage is configured to receive an additional working fluid flow separate from the second vapor working fluid flow through the first inlet. A second compressor stage of the compressor system is configured to receive the first vapor working fluid flow from the first economizer through a third inlet.

In another embodiment, a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system configured to circulate a working fluid comprises a first economizer configured to reduce a first working fluid pressure within the first economizer to provide a first vapor working fluid flow, a second economizer configured to reduce a second working fluid pressure within the second economizer to provide a second vapor working fluid flow, an evaporator configured to place the working fluid within the evaporator in heat exchange relationship with a refrigerant fluid to provide a third vapor working fluid flow, and a compressor system. The compressor system comprises a first compressor stage including a first inlet and a second inlet, the first inlet being configured to receive a first working fluid flow and the second inlet being configured to receive a second working fluid flow separate from the first working fluid flow, and a second compressor stage including a third inlet being configured to receive a third working fluid flow, wherein each of the first working fluid stream, the second working fluid stream, and the third working fluid stream comprises a different one of the first vapor working fluid stream, the second vapor working fluid stream, and the third vapor working fluid stream.

In another embodiment, a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system configured to circulate a working fluid comprises an economizer system comprising one or more economizers configured to reduce a pressure of the working fluid within the one or more economizers to provide one or more vapor working fluid streams and a compressor system. The compressor system comprises a first compressor stage comprising a first inlet and a second inlet, the first compressor stage configured to receive a first vapor working fluid stream of the one or more vapor working fluid streams through the second inlet, the first compressor stage configured to receive a further working fluid stream separate from the first vapor working fluid stream through the first inlet, and a second compressor stage comprising a third inlet configured to receive a second vapor working fluid stream of the one or more vapor working fluid streams through the third inlet.

There may be various improvements to the features mentioned above in connection with various aspects of the present disclosure. Additional features may also be incorporated into these various aspects. These improvements and additional features may exist individually or in any combination. For example, various features discussed below in connection with one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure, either alone or in any combination. The brief summary presented above is intended only to familiarize the reader with certain aspects and context of the embodiments of the present disclosure and is not intended to limit the claimed subject matter.

Various aspects of this disclosure can be better understood by reading the detailed description that follows and by reference to the drawings, in which:
FIG. 1 is a perspective view of a building utilizing one embodiment of a heating, ventilation, air conditioning, and/or cooling (HVAC&R) system in a commercial environment, according to one aspect of the present disclosure;
FIG. 2 is a perspective view of one embodiment of a vapor compression system according to one aspect of the present disclosure;
FIG. 3 is a schematic diagram of one embodiment of the vapor compression system of FIG. 2 according to one aspect of the present disclosure;
FIG. 4 is a schematic diagram of one embodiment of the vapor compression system of FIG. 2 according to one aspect of the present disclosure;
FIG. 5 is a schematic diagram of one embodiment of a vapor compression system including a compressor system having an economizer system and a compressor configured to receive a separated working fluid according to one aspect of the present disclosure;
FIG. 6 is a partial cross-sectional side view of one embodiment of a compressor configured to accommodate a separated working fluid according to one aspect of the present disclosure;
FIG. 7 is a schematic diagram of one embodiment of a compressor system including a compressor configured to receive a separated working fluid according to one aspect of the present disclosure;
FIG. 8 is a schematic diagram of one embodiment of a compressor system including a compressor configured to receive a separated working fluid according to one aspect of the present disclosure;
FIG. 9 is a schematic diagram of one embodiment of a compressor system including a compressor configured to receive a separated working fluid according to one aspect of the present disclosure;
FIG. 10 is a schematic diagram of one embodiment of a vapor compression system including a compressor system having an economizer system and a compressor configured to receive a separated working fluid according to one aspect of the present disclosure;
FIG. 11 is a schematic diagram of one embodiment of a vapor compression system including a compressor system having an economizer system and a compressor configured to receive a separated working fluid according to one aspect of the present disclosure;
FIG. 12 is a schematic diagram of one embodiment of a compressor system including a compressor configured to receive a separated working fluid according to one aspect of the present disclosure;
FIG. 13 is a schematic diagram of one embodiment of a vapor compression system including a compressor system having an economizer system and a compressor configured to receive a separated working fluid according to one aspect of the present disclosure;
FIG. 14 is a schematic diagram of one embodiment of a vapor compression system including a compressor system having an economizer system and a compressor configured to receive a separated working fluid according to one aspect of the present disclosure.

One or more specific implementations are described below. In an effort to provide a concise description of these implementations, not all features of an actual implementation are described herein. As with any engineering or design project, it should be recognized that many implementation-specific decisions must be made when developing any such actual implementation to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which may vary from implementation to implementation. It should also be recognized that while such development efforts may be complex and time-consuming, they would nonetheless be a routine undertaking for those skilled in the art having the benefit of this disclosure to design, fabricate, and manufacture.

When introducing elements of various embodiments of the present disclosure, expressions preceded by the article "a", "an", or "the" are intended to mean that one or more of the elements are present. The terms "comprising," "including," and "having" are intended to be inclusive and mean that additional elements may be present other than the listed elements. Additionally, it should be understood that reference to "one embodiment" or "an embodiment" of the present disclosure is not intended to be interpreted as excluding the presence of additional embodiments that also include the listed features.

As used herein, the terms "approximately," "generally," "substantially," and the like are intended to convey that the property value being described can be within a relatively small range of that property value, as would be understood by those of ordinary skill in the art. For example, when a property value is described as being "approximately" the same as (or, for example, "substantially similar to") a given value, this is intended to convey that the property value is within +/- 5% of the given value, within +/- 4%, within +/- 3%, within +/- 2%, within +/- 1%, or closer to the given value. Likewise, when a given feature is described as being "substantially parallel" to another feature, "generally perpendicular" to another feature, etc., this is intended to convey that the given feature is within +/- 5%, within +/- 4%, within +/- 3%, within +/- 2%, within +/- 1%, or closer to that property of being parallel to the other feature, perpendicular to the other feature, etc. Mathematical terms such as "parallel" and "perpendicular" are not to be construed strictly in their strict mathematical meaning, but instead should be understood as one of ordinary skill in the art would interpret such terms. For example, one of ordinary skill in the art would understand that two lines that are substantially parallel to each other may be substantially parallel, but may deviate slightly from being exactly parallel.

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 system configured to pressurize a working fluid within the vapor compression system and direct a refrigerant fluid to a condenser capable of cooling and condensing the working fluid. The condensed working fluid may be directed to an expansion device capable of further cooling the working fluid by reducing the pressure of the working fluid. From the expansion device, the cooled working fluid may be directed to an evaporator, where the evaporator may cool the refrigerant fluid by placing the working fluid in a heat exchange relationship with the refrigerant. The compressor system may then receive the working fluid from the evaporator for pressurization to restart the vapor compression cycle.

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 gaseous working fluid. The economizer may direct the liquid working fluid to the evaporator and direct the gaseous working fluid toward the compressor system for pressurization. To improve the performance (e.g., efficiency) of the vapor compression system, the compressor system may include multiple compressors or compressor stages (e.g., individual compressor impellers) that may each receive a gaseous working fluid stream from the economizers. As described herein, a single compressor stage may receive a gaseous working fluid stream and pressurize the gaseous working fluid stream to a higher pressure to provide a pressurized gaseous working fluid stream. For example, each compressor stage may receive a gaseous working fluid stream from one of the economizers and increase the pressure of the gaseous working fluid stream to a particular pressure that facilitates flow of the gaseous working fluid stream through the vapor compression system. For example, a compressor stage may increase the pressure of the gaseous working fluid stream toward the pressure of an additional working fluid stream (e.g., a working fluid stream pressurized by another compressor or compressor stage), thereby allowing for a desired flow (e.g., combined flow) of both the gaseous working fluid stream and the additional working fluid stream to the other component, instead of unwanted backflow of the working fluid into the compressor stage, uneven mixing between the working fluid streams, or other flow disturbances that would impede flow to the other component. Such flow disturbances may be caused by excessive pressure differences between the gaseous working fluid stream and the additional working fluid stream, which may reduce the efficient flow of the working fluid to the other 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 manufacturing, installing, and/or operating the vapor compression system.

Accordingly, it is now recognized that there is a need for improvements to HVAC&R systems having economizer systems. Accordingly, embodiments of the present disclosure are directed to a compressor system comprising a single compressor stage capable of receiving multiple separate working fluid streams. For example, the 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 pressurize both working fluid streams and discharge the pressurized working fluid streams to a condenser or another compressor stage. For example, the compressor stage may be a single-stage economizer compressor configured to receive the working fluid stream through the first inlet and an additional working fluid stream from the economizer through the second inlet so as to pressurize the two working fluid streams to approximately the same pressure. In practice, a single-stage economizer compressor may have multiple inlets configured to receive each working fluid stream, which may have a different suction pressure, and the single-stage economizer compressor may have a single impeller configured to pressurize each working fluid stream to a common increased pressure. Such a compressor stage may operate more efficiently in pressurizing the working fluid stream as compared to a compressor stage configured to receive a single inlet for the working fluid stream (e.g., a dedicated compressor stage for pressurizing a gaseous working fluid stream from a single economizer in the economizer system). That is, a compressor stage having multiple inlets may be configured to pressurize a relatively greater number of working fluid streams to a common pressure. Thus, a compressor system may utilize a limited number of compressor stages to pressurize gaseous working fluid streams from an economizer system (e.g., a separate gaseous working fluid stream), for example, an economizer system having multiple economizers or economizer stages. Thus, the manufacture, installation, and operation of a vapor compression system may be improved.

Referring now to the drawings, FIG. 1 is a perspective view of an exemplary 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 circuit) that supplies a chilled liquid that may be used to cool the building (12). The HVAC&R system (10) may also include a boiler (16) that supplies 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 an air handler (22). In some embodiments, the air handler (22) may include a heat exchanger connected to the boiler (16) and the vapor compression system (14) by a duct (24). The heat exchanger of the air handler (22) may receive heated liquid delivered from the boiler (16) or cooled liquid delivered from the vapor compression system (14), depending on the operating mode of the HVAC&R system (10). While the HVAC&R system (10) is shown as having a separate air handler for each floor of the building (12), in other implementations, the HVAC&R system (10) may include the air handler (22) and/or other components that may be shared between multiple floors.

Figures 2 and 3 are exemplary embodiments of a vapor compression system (14) that may be used in an HVAC&R system (10). The vapor compression system (14) may circulate refrigerant through a circuit that begins with a compressor (32). The circuit may also include a condenser (34), expansion valve(s) or device(s) (36), a liquid cooler 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), nonvolatile memory (46), and an interface board (48).

Some examples of fluids that may be used as refrigerants in a vapor compression system (14) include hydrofluorocarbon (HFC) based refrigerants, such as R-410A, R-407, R-134a, R-1234ze, R1233zd, hydrofluoroolefins (HFOs), ammonia (NH3), R-717, carbon dioxide (CO2), R-744, or "natural" refrigerants such as hydrocarbon based refrigerants, water vapor, or any other suitable refrigerant. In some embodiments, the vapor compression system (14) may be configured to efficiently utilize a refrigerant having a standard boiling point of about 19 degrees Celsius (66 degrees Fahrenheit) at 1 atmosphere, also referred to as a low pressure refrigerant to an intermediate pressure refrigerant, such as R-134a. As used herein, "standard boiling point" may refer to the boiling point temperature measured at 1 atmosphere.

In some embodiments, the vapor compression system (14) can utilize 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 an evaporator (38). The motor (50) can drive the compressor (32) and can be powered by the variable speed drive (VSD) (52). The VSD (52) receives alternating current (AC) power from an alternating current (AC) power source having a particular fixed line voltage and fixed line frequency, and provides power having a variable voltage and frequency to the motor (50). In other embodiments, the motor (50) can be powered directly from an AC or direct current (DC) power source. The motor (50) can 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 other suitable motor.

A compressor (32) compresses refrigerant vapor and delivers the vapor to a condenser (34) through a discharge passage. In some embodiments, the compressor (32) may be a centrifugal compressor. Refrigerant vapor delivered to the condenser (34) by the compressor (32) may transfer heat to a cooling fluid (e.g., water or air) within the condenser (34). The refrigerant vapor may be condensed into a refrigerant liquid in the condenser (34) as a result of thermal heat transfer with the cooling fluid. Liquid refrigerant from the condenser (34) may flow to the evaporator (38) through an expansion device (36). 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) that supplies a cooling fluid to the condenser (34).

The liquid refrigerant delivered to the evaporator (38) may or may not be the same refrigerant fluid used in the condenser (34). The liquid refrigerant within the evaporator (38) may undergo a phase change from liquid refrigerant to refrigerant vapor. As shown in the illustrated embodiment of FIG. 3, the evaporator (38) may include a tube bundle (58) having a return line (60R) and a supply line (60S) connected to a refrigeration load (62). A refrigerant fluid (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) in the evaporator (38) enters the evaporator (38) through the return line (60R) and exits the evaporator (38) through the supply line (60S). The evaporator (38) may lower the temperature of the refrigerant fluid in the tube bundle (58) through heat transfer with the refrigerant. The tube bundle (58) in the evaporator (38) may 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) via the suction line to complete the cycle.

FIG. 4 is a schematic diagram of a vapor compression system (14) having an intermediate circuit (64) integrated between a condenser (34) and an 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) located upstream of an intermediate vessel (70), which is integrated 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, 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).

Additionally, the intermediate vessel (70) may provide additional expansion of the liquid refrigerant due to the pressure drop experienced when the liquid refrigerant enters the intermediate vessel (70) (e.g., due to the rapid increase in volume experienced when entering the intermediate vessel (70). The vapor within the intermediate vessel (70) may be aspirated by the compressor (32) via a suction line (74) of the compressor (32). For example, the compressor (32) may comprise a single compressor stage configured to receive and pressurize both the vapor from the evaporator (38) and the vapor from the intermediate vessel (70) to a specified pressure. The liquid collected in the intermediate vessel (70) may be at a lower enthalpy than the liquid refrigerant exiting the condenser (34) due to expansion in the expansion device (66) and/or the intermediate vessel (70). The liquid from the intermediate vessel (70) may then flow to the evaporator (38) through a second expansion device (36) in line (72).

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

The present disclosure relates to an HVAC&R system having a compressor system comprising a compressor configured to receive and pressurize separate working fluid streams. For example, the compressor may include a first inlet configured to receive a first working fluid stream, such as from an evaporator and/or 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 vessel (70)). The compressor may pressurize the first working fluid stream and the second working fluid stream and discharge the pressurized working fluid stream (e.g., to a condenser, to another compressor). In this manner, a single compressor of the compressor system may be utilized to pressurize multiple separate working fluid streams. Thus, the compressor system may include fewer compressors as compared to compressor systems having compressor embodiments configured to receive and pressurize a single working fluid stream. In this manner, the compressor system may pressurize separate working fluid streams, including the working fluid stream received from the economizer, with reduced cost and/or complexity associated with manufacturing, installing, and/or operating the HVAC&R system.

With the above in mind, FIG. 5 is a schematic diagram of an exemplary embodiment of a vapor compression system or circuit (100) configured to circulate a working fluid (e.g., of an HVAC&R system). The vapor compression system (100) may include a condenser (102) configured to cool a working fluid (e.g., condenser (34)) and an evaporator (104) configured to place the working fluid in heat exchange relationship with a cooling fluid to absorb heat from the cooling fluid (e.g., evaporator (38)). 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 deliver the pressurized working fluid to the condenser (102).

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., multiple single-stage compressors arranged in series) for refrigerant flow through the compressor system (106). For example, the compressor system (106) may include a first compressor or first 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 second 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) toward the second compressor (112) as a first pressurized working fluid stream (114). The second compressor (112) can receive the first pressurized working fluid stream (114) and further pressurize the first pressurized working fluid stream (114) to discharge as a second pressurized working fluid stream (115) toward the condenser (102). Reference to an element (e.g., a system, a component, etc.) that propels a fluid (e.g., a vapor or liquid refrigerant) toward another element indicates that the element directly or indirectly pressurizes, forces, or guides (e.g., by piping, valves, mechanical actuation) the fluid to the other element.

The vapor compression system (100) may also include an economizer system (116) (e.g., an intermediate vessel 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 vaporize at least a portion of the working fluid and separate the working fluid into a liquid working fluid and a gaseous 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) can receive a working fluid from the condenser (102), reduce the pressure of the received working fluid to vaporize a portion of the received working fluid and separate the working fluid into a liquid working fluid and a gaseous working fluid, and send the liquid working fluid to the second economizer (120). The second economizer (120) can reduce the pressure of the received liquid working fluid to vaporize a portion of the working fluid received from the first economizer (118), separate the working fluid into a liquid working fluid and a gaseous working fluid, and send the liquid working fluid to the third economizer (122). The third economizer (122) can reduce the pressure of the received liquid working fluid to vaporize a portion of the working fluid received from the second economizer (120), separate the working fluid into a liquid working fluid and a gaseous working fluid, and send the liquid working fluid to the evaporator (104). Depending on current implementations, a varying number of economizers may be utilized in this arrangement.

Reducing the pressure of the refrigerant can further reduce the temperature of the refrigerant. Thus, 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 that the vapor compression system (100) provides to the refrigerant fluid, thereby increasing the efficiency of the vapor compression system (100). In certain embodiments, the economizer system (116) can comprise a single shell, housing, enclosure, or vessel, and each of the economizers (118, 120, 122) can comprise a separate chamber, compartment, or volume within the single shell. Additionally or alternatively, each of the economizers (118, 120, 122) can comprise a respective housing and/or enclosure that can be positioned adjacent to (e.g., joined to) one another to form the economizer system (116).

It should be noted that components of the vapor compression system (100) may be described as being positioned or arranged upstream or downstream of one another. As described herein, upstream and downstream may refer to the positioning of components with respect to the sequential flow of refrigerant through the vapor compression system (100), for example, 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), to the evaporator (104), and back to the compressor system (106). For example, upstream may refer to a location opposite the direction of refrigerant flow through the vapor compression system (100) (e.g., a preceding location), and downstream may refer to a location relative to the direction of refrigerant flow through the vapor compression system (100) (e.g., a succeeding location).

Each compressor (110, 112) can be configured to receive a gaseous working fluid from an economizer system (116). For example, the first economizer (118) and the second economizer (120) can discharge a first gaseous working fluid stream (124) and a second gaseous working fluid stream (126), respectively, to the second compressor (112) for pressurization. The third economizer (122) can discharge a third gaseous working fluid stream (128) to the first compressor (110) for pressurization. The first compressor (110) can include a first inlet (130) configured to receive a suction working fluid stream (113) from the evaporator (104) and a second inlet (132) separate from the first inlet (130) configured to receive a third gaseous working fluid stream (128) from the third economizer (122). Thus, the first compressor (110) can receive the suction working fluid stream (113) and the third gaseous working fluid stream (128) as separate working fluid streams for pressurization and discharge into a first pressurized working fluid stream (114). The second compressor (112) can include a third inlet (134) configured to receive the first pressurized working fluid stream (114) from the first compressor (110) and the second gaseous working fluid stream (126) from the second economizer (120). For example, the second gaseous working fluid stream (126) can 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 gaseous working fluid stream (126) and the first pressurized working fluid stream (114)) can be sent to the second compressor (112) via the third inlet (134). The second compressor (112) can also be configured to receive the first gaseous working fluid stream (124) from the first economizer (118) and can include a fourth inlet (136) separate from the third inlet (134). In this way, the second compressor (112) can receive the working fluid stream (135) combined with the first gaseous working fluid stream (124) as a separate working fluid stream, pressurized, and discharged 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 of different pressures.

Embodiments of the illustrated compressors (110, 112) configured to receive separate working fluid streams may 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) may receive multiple gaseous working fluid streams directly from the economizer system (116). Thus, fewer compressors may be utilized to pressurize the gaseous working fluid streams from the economizer system (116) as compared to a compressor system that includes dedicated individual compressors for receiving and pressurizing each gaseous working fluid stream from the economizer system (116). As such, the cost and/or complexity associated with manufacturing and/or operating the illustrated compressor system (106) may be reduced.

Although the illustrated vapor compression system (100) has a compressor system (106) comprising two compressors (110, 112) configured to receive gaseous 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 additional or alternative HVAC&R systems. 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) in the economizer system (116). For example, three compressors may be utilized to pressurize a gaseous working fluid stream from an economizer system (116) having five economizers, seven compressors may be utilized to pressurize a gaseous working fluid stream from an economizer system (116) having seven economizers, and so on. In such implementations, each compressor may accommodate multiple (e.g., two) separate working fluid streams for pressurization.

FIG. 6 is a partial cross-sectional side view of an embodiment of a compressor (160) (e.g., a compressor impeller system, a single-stage economizer compressor), such as a compressor (110) and/or a compressor (112). The compressor (160) can include a housing (162) (e.g., a compressor housing) in which an impeller (164) can 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 gaseous working fluid (126), a combined working fluid stream (135), a main suction stream) can enter the housing (162) from a suction inlet (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 be rotated during operation of the compressor (160) (e.g., via a motor), which drives the corresponding rotation of the impeller (164). The impeller (164) being driven to rotate may impart mechanical energy to a first working fluid stream (166). The first working fluid stream (166) may exit the impeller (164) and travel through a diffuser passage (172) (e.g., a pressure recovery portion) of the compressor (160) toward a volute (174) of the compressor (160). From the volute (174), the first working fluid stream (166) may be directed to a condenser (e.g., condenser (102)) and/or another compressor.

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

The initial pressure of the first working fluid stream (166) at the suction inlet (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 have different pressures. For example, the initial pressure of the first working fluid stream (166) may be lower than the initial pressure of the second working fluid stream (176). However, the compressor (160) may partially pressurize the first working fluid stream (166) toward the initial pressure of the second working fluid stream (176) through the impeller (164) before the flow of the first working fluid stream (166) reaches the flow junction (183). Thus, at the flow junction (183), the partially pressurized first working fluid stream (166) and the received second working fluid stream (176) can have substantially similar pressures. The similar pressures of the working fluid streams (166, 176) at the flow junction (183) can facilitate directing the working fluid streams (166, 176) toward the diffuser passage (172) instead of in the countercurrent direction toward the suction inlet (168) and/or the economizer inlet (180), for example, due to the pressure difference between the first working fluid stream (166) and the second working fluid stream (176) at the flow junction (183). In this manner, the compressor (160) can facilitate directing each of the first working fluid stream (166) and the second working fluid stream (176) for discharge toward the volute (174). The compressor (160) can further pressurize the working fluid stream (166, 176) sent downstream of the flow junction (183) through the diffuser passage (172), for example to a common increased pressure for discharge.

In certain embodiments, the impeller (164) can include blades (184) that can force a first working fluid stream (166) through the housing (162), through the diffuser passage (172), and into the volute (174) during rotation of the impeller (164). The impeller (164) can also include a shroud (186) integral with the blades (184) to surround and cover the blades (184) (e.g., shield a portion of the blades (184), such as the tip (185), from the housing (162). The first working fluid stream (166) can 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) can be directed through the housing (162) and along a passage (188) extending between the shroud (186) and the housing (162) toward the diffuser passage (172) such that the second working fluid stream (176) combines with the first working fluid stream (166) (e.g., the first working fluid stream partially pressurized to about the same pressure as the second working fluid stream (176)) at a flow junction (183). The shroud (186) can block 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) can combine with each other downstream of the tip (185) of the blade (184) for 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) can combine with each other upstream of the tip (185) of the blade (184) for flow of the working fluid through the compressor (160) and toward the diffuser passage (172). In either case, the suction inlet (168) and the economizer inlet (180) allow the compressor (160) to receive separate working fluid streams for pressurization and discharge.

FIG. 7 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 dual-ended (e.g., dual-ended two single-ended compressor) configuration, where the first compressor impeller (210) is coupled to a first end (216) of the shaft (214) and the second compressor impeller (212) is coupled to a second end (218) of the shaft (214) that is opposite the first end (216). Therefore, the rotation of the shaft (214) through the motor (220) can drive the rotation of each of the first compressor impeller (210) and the second compressor impeller (212).

The first compressor (110) may receive a suction working fluid stream (113) through a first inlet (130) (e.g., a suction inlet), such as from an evaporator (104), and pressurize the suction working fluid stream (113). The first compressor (110) may also receive a third gaseous working fluid stream (128) from a third economizer (122) through a second inlet (132) (e.g., an economizer inlet), and the suction working fluid stream (113) (e.g., a partially pressurized suction working fluid stream (113)) and the third gaseous working fluid stream (128) may be combined and flowed toward the first volute (224). The first compressor (110) can discharge the suction working fluid stream (113) and the third gaseous working fluid stream (128) from the first volute (224) toward the second compressor (112) as a first pressurized working fluid stream (114).

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

In the illustrated embodiment, the first compressor (110) and the second compressor (112) are oriented in opposite directions. For example, the first inlet (130) of the first compressor (110) and the third inlet (134) of the second compressor (112) face in opposite directions. For this reason, 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) opposite to the first rotational direction (228) (e.g., counterclockwise rotation). In additional or alternative embodiments, the first compressor (110) and the second compressor (112) may be oriented in opposite directions 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 additional 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).

FIG. 8 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 a suction working fluid stream (113) (e.g., from an evaporator (104)) and/or a third gaseous working fluid stream (128) (e.g., from a third economizer (122)) and discharge the suction working fluid stream (113) and/or the third gaseous working fluid stream (128) as a first pressurized working fluid stream (114) toward the second compressor (112). The second compressor (112) can receive and pressurize the first pressurized working fluid stream (114), the first gaseous working fluid stream (124) (e.g., from the first economizer (118)) and/or the second gaseous working fluid stream (126) (e.g., from the second economizer (120)) and discharge the first pressurized working fluid stream (114), the first gaseous working fluid stream (124) and/or the second gaseous working fluid stream (126) as a second pressurized working fluid stream (115) toward the condenser (102).

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

In the illustrated embodiment, the compressors (110, 112) are positioned at a common end (252) of the shaft (214) (e.g., the first end (216)). For example, the common end (252) may comprise a driven end of the shaft (214), or an end of the shaft (214) that can be subjected to a significant radial load or force (e.g., a force applied perpendicular to the axis of rotation of the shaft (214). As another example, the common end (252) may comprise a non-driven end of the shaft (214) that is opposite the driven end for an overhang (e.g., a double overhang, two single stages overhang) configuration of the compressor system (106). Additionally, 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 an alternative embodiment the compressors (110, 112) may be oriented such that the first inlet (130) and the third inlet (134) face toward the motor (220).

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 drive rotation of the first compressor impeller (210) by rotating the first shaft (280), 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 drive rotation of the second compressor impeller (212) by rotating the second shaft (284), 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 rotation 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 that described above, with the first compressor (110) receiving and pressurizing the suction working fluid stream (113) and/or the third gaseous working fluid stream (128) and discharging the suction working fluid stream (113) and/or the third gaseous working fluid stream (128) as a first pressurized working fluid stream (114) toward the second compressor (112). Moreover, the second compressor (112) can receive and pressurize the first pressurized working fluid stream (114), the first gaseous working fluid stream (124), and the second gaseous working fluid stream (126) (e.g., the combined working fluid stream (135) and the first gaseous working fluid stream (124)) and discharge the first pressurized working fluid stream (114), the first gaseous working fluid stream (124), and the second gaseous working fluid stream (126) as the second pressurized working fluid stream (115) toward the condenser (102).

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 implementations, the compressors (110, 112) may be oriented in different directions, such as an arrangement where the first inlet (130) and the third inlet (134) face opposite directions, an arrangement where the first inlet (130) and the third inlet (134) face intersecting directions, etc. In practice, the shafts (280, 284) may be arranged in any suitable manner to orient the compressors (110, 112) in corresponding directions.

In the embodiments described above, the compressors (110, 112) are positioned in a serial flow arrangement such that the working fluid can be sent from the first compressor (110) to the second compressor (112). In additional or alternative embodiments, the compressors (110, 112) can be positioned in a parallel flow arrangement such that the working fluid is sent to one of the compressors (110, 112) and not to the other of the compressors (110, 112) before being sent to the condenser (102). For example, the first compressor (110) and the second compressor (112) can each discharge their respective working fluid streams directly to the condenser (102).

FIG. 10 is a schematic diagram of an embodiment of a vapor compression system (100) having a first compressor (110) and a second compressor (112) in a parallel flow arrangement. The first compressor (110) may receive and pressurize an intake working fluid stream (113) (e.g., from an evaporator (104) via a first inlet (130)) and/or a third gaseous working fluid stream (128) (e.g., from a third economizer (122) via a second inlet (132)) to provide a first pressurized working fluid stream (114). However, the first compressor (110) may discharge the first pressurized working fluid stream (114) to a condenser (102) rather than to the second compressor (112). Thus, the first pressurized working fluid stream (114) can flow directly from the first compressor (110) to the condenser (102), bypassing the flow through the second compressor (112). The second compressor (112) can receive and pressurize the first gaseous working fluid stream (124) (e.g., via the fourth inlet (136)) and/or the second gaseous working fluid stream (126) (e.g., via the third inlet (134)) to discharge the first gaseous working fluid stream (124) and/or the second gaseous 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) can be combined and flowed through 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) can flow to the condenser (102) as separate fluid streams, such as through different inlets of the condenser (102). In a parallel flow arrangement, the first compressor (110) and the second compressor (112) can be coupled to a common shaft or coupled to separate shafts.

In addition to or alternatively to embodiments having multiple inlets configured to receive separate working fluid streams of the compressors (110, 112) (e.g., as represented by compressor (160)), the vapor compression system (100) may also include an embodiment of a compressor 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) may receive separate working fluid streams, for example, an intake working fluid stream (113) through a first inlet (130) and a second gaseous working fluid stream (126) through a second inlet (132). The first compressor (110) may pressurize the intake working fluid stream (113) and/or the second gaseous working fluid stream (126) to provide a first pressurized working fluid stream (114).

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) capable of receiving a first pressurized working fluid stream (114). Thus, the first compressor (110) and the third compressor (350) may be in a serial flow arrangement where the third compressor (350) is positioned downstream of the first compressor (110) with respect to the flow of working fluid through the compressor system (106). In some implementations, the first gaseous working fluid stream (124) delivered by the first economizer (118) can be combined with the first pressurized working fluid stream (114) as a combined working fluid stream (354), and the third compressor (350) can receive and pressurize the combined working fluid stream (354) to provide a second pressurized working fluid stream (115) for discharge toward the condenser (102). However, the third compressor (350) may not include an inlet other than the fifth inlet (352), and thus may not receive a separate working fluid stream (e.g., a third gaseous working fluid stream (128) from the third economizer (122) that may otherwise be integrated into the economizer system (116).

FIG. 12 is 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) can receive and pressurize an intake working fluid stream (113) and/or a second gaseous working fluid stream (126) and discharge them as a first pressurized working fluid stream (114) directed to the third compressor (350). The third compressor (350) can receive and pressurize the first pressurized working fluid stream (114) and/or the first gaseous working fluid stream (124) (e.g., the combined working fluid stream (354)) through a fifth inlet (352) and discharge them as a second pressurized working fluid stream (115) directed to the condenser (102). For example, the third compressor (350) can include a third compressor impeller (380) that can impart mechanical energy to the first pressurized working fluid stream (114) and/or the first gaseous working fluid stream (124) (e.g., the combined working fluid stream (354)) so as to direct the first pressurized working fluid stream (114) and/or the first gaseous working fluid stream (124) to the third volute (382). The third compressor (350) can discharge the first pressurized working fluid stream (114) and/or the first gaseous working fluid stream (124) from the third volute (382) toward the condenser (102) as a second pressurized working fluid stream (115).

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). Accordingly, operation of the motors (282, 286) may cause rotation of each of the compressors (110, 350) (e.g., rotation of each of the 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)), for example, at opposite ends of the shaft and/or at a common end of the shaft. Thus, operation of the motor may cause both compressors (110, 350) to rotate.

FIG. 13 is a schematic diagram of an embodiment of a compressor system (106) having a first compressor (110) and a third compressor (350) in a serial flow arrangement. In the illustrated embodiment, the first compressor (110) is located downstream of the third compressor (350) with respect to the flow of working fluid through the compressor system (106). For example, the third compressor (350) may receive a suction working fluid stream (113) from the evaporator (104) through a fifth inlet (352), 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 first compressor (110). The first compressor (110) can receive a pressurized suction working fluid stream (113) (e.g., the first pressurized working fluid stream (114)) and/or a second gaseous working fluid stream (126) (e.g., the combined working fluid stream (117)) through a first inlet (130). The first compressor (110) can also receive a first gaseous working fluid stream (124) through a second inlet (132). The first compressor (110) can pressurize the suction working fluid stream (113), the first gaseous working fluid stream (124), and the second gaseous working fluid stream (126) and discharge the pressurized working fluid streams as the second pressurized working fluid stream (115) to the condenser (102).

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 an intake working fluid stream (113) and/or a second gaseous 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), bypassing the third compressor (350). The third compressor (350) may receive and pressurize the first gaseous working fluid stream (124) and discharge the pressurized first gaseous working fluid stream (124) to the condenser (102) as a second pressurized working fluid stream (115) bypassing the first compressor (110). In additional or alternative embodiments, the third compressor (350) can receive and pressurize the intake working fluid stream (113) and discharge it to the condenser (102) bypassing the first compressor (110), and the first compressor (110) can receive and pressurize the second gaseous working fluid stream (126) and/or the first gaseous working fluid stream (124) and discharge it to the condenser (102) bypassing the third compressor (350). In any of these embodiments, the first compressor (110) and the third compressor (350) can be coupled to a common shaft or coupled to separate shafts.

While only certain features and embodiments of the present invention have been illustrated and described, it will be understood that many modifications and changes may occur to those skilled in the art (e.g., changes in size, dimensions, structure, shape, and proportion of the various elements, values of parameters (e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, 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 changed or rearranged to obtain alternative embodiments. Accordingly, it is to be noted that the appended claims are intended to cover all such modifications and variations as fall within the true spirit of the invention. It is also to be understood that in an effort to provide a concise description of exemplary embodiments, not all features of an actual implementation may be described (i.e., those that do not relate to the presently contemplated best mode of carrying out the invention or those that do not relate to enabling the claimed embodiments). It should be recognized that, as in any engineering or design project, numerous specific decisions may be made in developing any such actual implementation. While such development efforts may be complex and time consuming, they will nonetheless become routine tasks of design, fabrication, and manufacture without undue experimentation for those skilled in the art having the benefit of this disclosure.

The technology shown and claimed herein is directed to and applied to tangible, tangible objects and concrete examples of a practical nature that clearly improve the state of the art, and therefore is not abstract, intangible, or purely theoretical. Furthermore, if any claim appended to the end of this specification includes one or more elements designated as "... a means for [performing] [the function]" or "... a step for [performing] [the function]," then such elements are intended to be interpreted in accordance with 35 U.S.C. 112(f). However, for any claim that includes elements designated in any other manner, such elements are not intended to be interpreted in accordance with 35 U.S.C. 112(f).

Claims (20)

A heating, ventilation, air conditioning and refrigeration (HVAC&R) system configured to circulate a working fluid,
A first economizer and a second economizer, wherein the first economizer is configured to reduce a first working fluid pressure within the first economizer to provide a first vapor working fluid flow, and the second economizer is configured to reduce a second working fluid pressure within the second economizer to provide a second vapor working fluid flow; 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 the second vapor working fluid flow from the second economizer through the second inlet, and the first compressor stage is configured to receive an additional working fluid flow separate from the second vapor working fluid flow through the first inlet; and
An HVAC&R system comprising a second compressor stage including a third inlet, said second compressor stage configured to receive said first vapor working fluid flow from said first economizer through said third inlet. An HVAC&R system according to claim 1, comprising an evaporator configured to place the working fluid in a heat exchange relationship with a cooling fluid, wherein the additional working fluid flow is received from the evaporator. An HVAC&R system according to claim 1, wherein the first compressor stage is configured to pressurize the second vapor working fluid stream and the additional working fluid stream and discharge them as pressurized working fluid streams into the second compressor stage, and the second compressor stage is configured to receive the pressurized working fluid stream from the first compressor stage through a fourth inlet. An HVAC&R system according to claim 3, wherein the second compressor stage is configured to pressurize the first vapor working fluid stream and the pressurized working fluid stream and discharge them to the condenser for cooling via the condenser. An HVAC&R system according to claim 3, wherein the economizer system comprises a third economizer configured to reduce a third working fluid pressure within the third economizer to provide a third vapor working fluid flow, and wherein the second compressor stage is configured to receive the third vapor working fluid flow from the third economizer through the fourth inlet. An HVAC&R system according to 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 through the fourth inlet. An HVAC&R system according to claim 1, comprising a condenser configured to cool the working fluid, wherein the economizer system is configured to receive the working fluid from the condenser. An HVAC&R system according to claim 1, wherein the first compressor stage comprises a first impeller, the second compressor stage comprises a second impeller, and the first impeller and the second impeller are attached to a common shaft. An HVAC&R system according to claim 1, wherein the first compressor stage comprises a first impeller, the second compressor stage comprises a second impeller, and the first impeller and the second impeller are attached to separate shafts. An HVAC&R system according to claim 1, wherein the first economizer is configured to reduce the pressure of the working fluid within 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 within the second economizer to provide a second liquid working fluid flow and a second vapor working fluid flow. A vapor compression system for a heating, ventilation, air conditioning and refrigeration (HVAC&R) system, wherein the vapor compression system is configured to circulate a working fluid, the vapor compression system comprising:
A first economizer configured to reduce a first working fluid pressure within the first economizer to provide a first vapor working fluid flow;
A second economizer configured to reduce the pressure of a second working fluid within the second economizer to provide a second vapor working fluid flow;
An evaporator configured to provide a third vapor working fluid flow by placing the working fluid within the evaporator in a heat exchange relationship with a cooling fluid; 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 separated from the first working fluid stream; and
A vapor compression system comprising a second compressor stage including a third inlet configured to receive a third working fluid stream, each of said first working fluid stream, said second working fluid stream, and said third working fluid stream comprising a different one of said first vapor working fluid stream, said second vapor working fluid stream, and said third vapor working fluid stream. A vapor compression system according to claim 11, wherein each of the first compressor stage and the second compressor stage is a single-stage economizing compressor, the first compressor stage comprises a first impeller, the second compressor stage comprises a second impeller, and the first impeller and the second impeller are coupled to different shafts. A vapor compression system according to claim 11, wherein the first compressor stage is configured to receive the third vapor working fluid flow from the evaporator through the first inlet as the first working fluid flow, and is configured to separately receive the second vapor working fluid flow from the second economizer through the second inlet as the second working fluid flow, and the second compressor stage is configured to receive the first vapor working fluid flow from the first economizer through the third inlet as the third working fluid flow. A vapor compression system according to claim 11, comprising a condenser configured to cool the working fluid, wherein the first economizer is configured to receive the working fluid from the condenser. A heating, ventilation, air conditioning and refrigeration (HVAC&R) system configured to circulate a working fluid,
An economizer system comprising one or more economizers configured to reduce a working fluid pressure within 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 through 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 through the first inlet; and
An HVAC&R system comprising a second compressor stage including a third inlet, the second compressor stage configured to receive a second vapor working fluid stream of the one or more vapor working streams through the third inlet. An HVAC&R system according to claim 15, wherein the second compressor stage comprises a fourth inlet, the first compressor stage is configured to discharge the first vapor working fluid stream and the additional working fluid stream as pressurized working fluid streams, and the second compressor stage is configured to receive the pressurized working fluid stream through the fourth inlet. An HVAC&R system according to 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 through the fourth inlet. An HVAC&R system according to claim 17, wherein a first economizer of the one or more economizers is configured to provide the first vapor working fluid flow, a second economizer of the one or more economizers is configured to provide the second vapor working fluid flow, and a third economizer of the one or more economizers is configured to provide the third vapor working fluid flow. In claim 15,
A condenser configured to cool said working fluid, said economizer system configured to receive said working fluid from said condenser;
An HVAC&R system comprising an evaporator configured to place said working fluid in a heat exchange relationship with a cooling fluid, wherein said first compressor stage is configured to receive said additional working fluid flow from said evaporator. An HVAC&R system according to claim 15, wherein the first compressor stage comprises a first impeller, the second compressor stage comprises a second impeller, and the first impeller and the second impeller are coupled to a common shaft.