Oil-Free Phase Separating Compressor

This disclosure relates generally to a compressor. More specifically, this disclosure relates to directing of working fluid within a compressor in a refrigerant circuit in a heating, ventilation, air conditioning, and refrigeration (HVACR) system.

Compressors utilize a compression mechanism (e.g., intermeshing scroll members, intermeshed screws, impeller, or the like) to compress a fluid. Heating, ventilation, air conditioning, and refrigeration systems (“HVACR”) may utilize compressors to compress a gaseous working fluid. Typically, a non-fixed member of the compression mechanism (e.g., an orbiting scroll, rotating screw, impeller, or the like) is moved (e.g., rotated, orbited, or the like) is rotated by a crankshaft. The compressor can include bearing(s) for supporting the crankshaft while it rotates.

In an embodiment, an oil-free compressor includes a compressor housing, a compression mechanism disposed within the compressor housing, a crankshaft engaged with the compression mechanism, a bearing for supporting the crankshaft, and a liquid-vapor separation volume disposed within the compressor housing. The compressor housing including a suction inlet and a discharge outlet. The compression mechanism has an inlet fluidly connected to the suction inlet and a discharge volume fluidly connected to the discharge outlet. Rotation of the crankshaft is configured to drive the compression mechanism to provide compression. The liquid-vapor separation volume configured to separate a mixed phase of working fluid into liquid working fluid and gaseous working fluid. The liquid working fluid is supplied to the bearing.

In an embodiment, an inner enclosure is disposed in the compressor housing. A motor is disposed in the inner enclosure and is configured to rotate the crankshaft. The crankshaft includes an interior gallery. The rotation of the crankshaft is configured to supply a portion of the liquid working fluid through the interior gallery and one or more liquid passages into the inner enclosure.

In an embodiment, the oil-free compressor is a scroll compressor, the compression mechanism being a pair of intermeshed scroll members, the crankshaft engaged with a non-fixed scroll member in the pair of intermeshed scroll members. The one or more liquid passages include a first liquid passage that fluidly connects the interior gallery of the crankshaft to an alignment coupler for the pair of intermeshed scroll members and a second liquid passage that fluidly connects the alignment coupler to the inner enclosure.

In an embodiment, the compressor housing includes a separator inlet for the liquid-vapor separation volume and a separator outlet for the liquid-vapor separation volume. The compression mechanism forms compression pockets within the compressor housing, an intermediate injection port fluidly connects the liquid-vapor separation volume to at least one of the compression pockets.

In an embodiment, the liquid-vapor separation volume is configured to receive, via the separator inlet, the mixed phase of the working fluid, and to discharge the liquid working fluid from the compressor through the separator outlet.

In an embodiment, the intermediate injection port is configured to direct the gaseous working fluid into the at least one of the compression pockets.

In an embodiment, the compression mechanism is configured to compress the working fluid from an inlet pressure to a discharge pressure. The liquid-vapor separation volume is configured to receive the working fluid at an intermediate pressure that is between the inlet pressure and the discharge pressure.

In an embodiment, the suction inlet is fluidly connected to the liquid-vapor separation volume, a suction passageway fluidly connecting the liquid-vapor separation volume to the inlet of compression mechanism.

In an embodiment, the liquid-vapor separation volume is configured to receive, via the suction inlet, the mixed phase of the working fluid and to separate the gascous working fluid from the liquid working fluid within the liquid-vapor separation. The suction passageway is configured to direct the gaseous working fluid to the inlet of the compression mechanism.

In an embodiment, a heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a refrigerant circuit. The refrigerant circuit includes an oil-free compressor configured to compress a working fluid, a condenser configured to cool the working fluid compressed by the oil-free compressor, one or more expanders configured to expand the working fluid cooled by the condenser, and an evaporator configured to cool a second process fluid using the working fluid expanded by the one or more expanders. The oil-free compressor includes a compressor housing, a compression mechanism disposed within the compressor housing, a crankshaft engaged with the compression mechanism, a bearing for supporting the crankshaft, and a liquid-vapor separation volume disposed within the compressor housing. The compressor housing includes a suction inlet and a discharge outlet. The compression mechanism has an inlet fluidly connected to the suction inlet and a discharge volume fluidly connected to the discharge outlet. Rotation of the crankshaft is configured to drive the compression mechanism to compress the working fluid. The liquid-vapor separation volume configured to separate a mixed phase of the working fluid into liquid working fluid and a gascous working fluid, the liquid working fluid is supplied to the bearing.

In an embodiment, the oil-free compressor includes an inner enclosure disposed in the compressor housing and a motor disposed in the inner enclosure. The motor is configured to rotate the crankshaft. The crankshaft includes an interior gallery. The rotation of the crankshaft is configured to supply a portion of the liquid working fluid through the interior gallery and one or more liquid passages into the inner enclosure.

In an embodiment, the oil-free compressor is a scroll compressor and the compression mechanism being a pair of intermeshed scroll members. The crankshaft is engaged with a non-fixed scroll member in the pair of intermeshed scroll members. The one or more liquid passages include a first liquid passage that fluidly connects the interior gallery of the crankshaft to an alignment coupler for the pair of intermeshed scroll members and a second liquid passage that fluidly connects the alignment coupler to the inner enclosure.

In an embodiment, the compressor housing includes a separator inlet for the liquid-vapor separation volume and a separator outlet for the liquid-vapor separation volume. The one or more expanders include a first expander fluidly connecting the condenser to the separator inlet of the compressor and a second expander fluidly connecting the separator outlet of the compressor to the evaporator. The compression mechanism forms compression pockets within the compressor housing. The compressor includes an intermediate injection port that fluidly connects the liquid-vapor separation volume to at least one of the compression pockets.

In an embodiment, the separator inlet is configured to receive the mixed phase of the working fluid from the first expander. The second expander is configured to receive the liquid working fluid from the outlet of the separator outlet.

In an embodiment, the intermediate injection port is configured to direct the gaseous working fluid into the at least one of the compression pockets.

In an embodiment, the suction inlet is fluidly connected to the liquid-vapor separation volume. A suction passageway fluidly connects the liquid-vapor separation volume to the inlet of the compression mechanism.

In an embodiment, the liquid-vapor separation volume is configured to receive, via the suction inlet, the mixed phase of the working fluid and to separate the gascous working fluid from the liquid working fluid within the liquid-vapor separation. The suction passageway is configured to direct the gaseous working fluid to the inlet of the compression mechanism.

In an embodiment, an oil-free scroll compressor includes a compressor housing, a pair of intermeshed scroll members disposed in the compressor housing, a crankshaft, a bearing for supporting the crankshaft, and a liquid-vapor separation volume disposed within the compressor housing. The compressor housing includes a suction inlet and a discharge outlet. The pair of intermeshed scroll members have an inlet fluidly connected to the suction inlet and a discharge volume fluidly connected to the discharge outlet. The crankshaft is engaged with a non-fixed scroll member in the pair of intermeshed scroll members. The liquid-vapor separation volume is configured to separate a mixed phase of the working fluid into liquid working fluid and gascous working fluid, wherein the liquid working fluid is supplied to the bearing.

In an embodiment, the compressor also includes an inner enclosure disposed in the compressor housing and a motor is disposed in the inner enclosure. The crankshaft includes an interior gallery. The motor is configured to rotate the crankshaft, and the rotation of the crankshaft is configured to supply a portion of the liquid working fluid through the interior gallery and one or more liquid passages into the inner enclosure.

In an embodiment, the one or more liquid passages include a first liquid passage and a second liquid passage. The first liquid passage fluidly connects the interior gallery of the crankshaft to an alignment coupler for the pair of intermeshed scroll members. The second liquid passage fluidly connects the alignment coupler to the inner enclosure.

In an embodiment, the compressor housing includes a separator inlet for the liquid-vapor separation volume and a separator outlet for the liquid-vapor separation volume. The pair of intermeshed scroll members are intermeshed to form compression pockets within the compressor housing. An intermediate injection port fluidly connects the liquid-vapor separation volume to at least one of the compression pockets.

In an embodiment, the liquid-vapor separation volume is configured to receive, via the separator inlet, the mixed phase of the working fluid, and to discharge the liquid working fluid from the compressor through the separator outlet.

In an embodiment, the intermediate injection port is configured to direct the gaseous working fluid into the at least one of the compression pockets.

In an embodiment, the pair of intermeshed scroll members is configured to compress the working fluid from an inlet pressure to a discharge pressure. The liquid-vapor separation volume is configured to receive the working fluid at an intermediate pressure that is between the inlet pressure and the discharge pressure.

In an embodiment, the suction inlet is fluidly connected to the liquid-vapor separation volume, a suction passageway fluidly connecting the liquid-vapor separation volume to the inlet of the pair of scroll members.

In an embodiment, the liquid-vapor separation volume is configured to receive, via the suction inlet, the mixed phase of the working fluid and to separate the gascous working fluid from the liquid working fluid within the liquid-vapor separation. The suction passageway is configured to direct the gaseous working fluid to the inlet of the pair of intermeshed scroll members.

In an embodiment, a heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a refrigerant circuit. The refrigerant circuit includes an oil-free scroll compressor configured to compress a working fluid, a condenser configured to cool the working fluid compressed by the intermeshed scroll compressor, one or more expanders configured to expand the working fluid cooled by the condenser, and an evaporator configured to cool a second process fluid using the working fluid expanded by the one or more expanders. The oil-free scroll compressor includes a compressor housing, a pair of intermeshed scroll members disposed in the compressor housing, a crankshaft, a bearing for supporting the crankshaft, and a liquid-vapor separation volume disposed within the compressor housing. The compressor housing includes a suction inlet and a discharge outlet. The pair of intermeshed scroll members have an inlet fluidly connected to the suction inlet and a discharge volume fluidly connected to the discharge outlet. The crankshaft is engaged with a non-fixed scroll member in the pair of intermeshed scroll members. The liquid-vapor separation volume is configured to separate a mixed phase of the working fluid into liquid working fluid and gaseous working fluid, wherein the liquid working fluid is supplied to the bearing.

In an embodiment, the compressor includes an inner enclosure disposed in the compressor housing and a motor is disposed in the inner enclosure. The crankshaft includes an interior gallery. The motor is configured to rotate the crankshaft. The rotation of the crankshaft is configured to supply a portion of the liquid working fluid through the interior gallery and one or more liquid passages into the inner enclosure.

In an embodiment, the one or more liquid passages include a first liquid passage and a second liquid passage. The first liquid passage fluidly connects the interior gallery of the crankshaft to an alignment coupler for the pair of intermeshed scroll members. The second liquid passage that fluidly connects the alignment coupler to the inner enclosure.

In an embodiment, the compressor housing of the compressor includes a separator inlet for the liquid-vapor separation volume and a separator outlet for the liquid-vapor separation volume. The one or more expanders include a first expander and a second expander. The first expander fluidly connects the condenser to the separator inlet of the compressor. The second expander fluidly connects the separator outlet of the compressor to the evaporator. The pair of intermeshed scroll members are intermeshed to form compression pockets within the compressor housing. An intermediate injection port fluidly connecting the liquid-vapor separation volume to at least one of the compression pockets.

In an embodiment, the separator inlet is configured to receive the mixed phase of the working fluid from the first expander. The second expander is configured to receive the liquid working fluid from the outlet of the separator outlet.

In an embodiment, the intermediate injection port is configured to direct the gaseous working fluid into the at least one of the compression pockets.

In an embodiment, the suction inlet is fluidly connected to the liquid-vapor separation volume. A suction passageway fluidly connects the liquid-vapor separation volume to the inlet of the pair of intermeshed scroll members.

In an embodiment, the liquid-vapor separation volume is configured to receive, via the suction inlet, the mixed phase of the working fluid and to separate the gaseous working fluid from the liquid working fluid within the liquid-vapor separation. The suction passageway is configured to direct the gaseous working fluid to the inlet of the pair of intermeshed scroll members.

In an embodiment, the HVACR system also includes a level sensor for the liquid-vapor separation volume and a controller. The controller is configured to detect, using the level sensor, a liquid level of the liquid working fluid in the liquid-vapor separation volume is also configured to control the one or more expanders based on the liquid working fluid in the liquid-vapor separation volume.

In an embodiment, the one or more expanders includes a first expander. The controller is configured to adjust the first expander based on the liquid level in the liquid-vapor separation volume.

In an embodiment, the controller is configured to adjust a valve position of the first expander based on the liquid working level in the liquid-vapor separation volume to be above or below a predetermined level.

This disclosure relates generally to a scroll compressor. More specifically, this disclosure relates to directing of working fluid within a scroll compressor in a heating, ventilation, air conditioning, and refrigeration (HVACR) system.

Scroll compressors compress gas in compression pockets formed by the intermeshing scroll members. Scroll compressor generally include one or more mechanical components that require lubrication. In an oil-free compressor, oil is not available or used for lubricating such mechanical components. A scroll compressor can also include a motor that drives the movement of the non-fixed scroll member. During operation, the motor can generate heat which can buildup in the motor and reduce the operating speed of motor, decrease the efficiency of the motor, and/or damage the motor.

In some configurations, a refrigerant circuit can be configured to have an economizer. The economizer separates gaseous working fluid at an intermediate pressure from a mixed phase working fluid and supplies the intermediate pressure gaseous working fluid to the scroll compressor. The intermediate pressure gaseous working fluid is directed into compression pocket(s) of the intermeshed scroll members which may increase the efficiency and/or the capacity of the refrigerant circuit.

Embodiments of this disclosure are directed to oil-free scroll compressors having a liquid-vapor separation volume for separating liquid and gaseous working fluid therein and supplying the liquid working fluid to lubricate the mechanical component(s) of the scroll compressor. In some embodiments, a heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a refrigerant circuit with an oil-free scroll compressor. In some embodiments, the compressor includes an inner enclosure for the motor, and a portion of the liquid working fluid is supplied to said enclosure to help cool the motor. In some embodiments, the liquid-vapor separation volume separates an intermediate pressure working fluid and the separated gaseous intermediate pressure working fluid is supplied to the compression pocket(s). In some embodiments, the liquid-vapor separation volume separates an inlet pressure working fluid and the separated inlet pressure gaseous working fluid flows is supplied to an inlet of the intermeshed scrolls.

is a schematic diagram of an embodiment of a refrigerant circuitin a heating, ventilation, air conditioning, and refrigeration (HVACR) system. In an embodiment, the HVACR systemmay be an industrial, commercial, or residential HVACR systemconfigured to condition the inside of a building (e.g., office space, residential house, or the like). In an embodiment, the HVACR systemmay be a transport HVACR use for cooling the inside of a transport unit (e.g., shipping container, transport/trucking container, reefer, or the like) and/or a passenger vehicle (e.g., a bus, a plane, or the like).

The refrigerant circuitincludes a compressor, a condenser, a first expansion device, a second expansion device, and an evaporator. In an embodiment, the refrigerant circuitcan be modified to include additional components. For example, the refrigerant circuitin an embodiment can include one or more flow control devices, a receiver tank, a dryer, a suction-liquid heat exchanger, or the like. The components of the refrigerant circuitare fluidly connected. Dotted lines are provided into indicate fluid flows through some components (e.g., compressor, condenser, evaporator) for clarity, and should be understood as not specifying a specific route within each component.

The refrigerant circuitcan be configured as a cooling system (e.g., a fluid chiller of an HVACR, an air conditioning system, or the like) that can be operated in a cooling mode, and/or the refrigerant circuitcan be configured to operate as a heat pump system that can run in a cooling mode and a heating mode.

The refrigerant circuitapplies known principles of gas compression and heat transfer. The refrigerant circuitcan be configured to heat or cool a process fluid (e.g., water, air, chiller fluid, or the like). In an embodiment, the refrigerant circuitmay represent a chiller that cools a process fluid such as water or the like. In an embodiment, the refrigerant circuitmay represent an air conditioner and/or a heat pump that cools and/or heats a process fluid such as air, water, or the like.

During the operation of the refrigerant circuit, a working fluid (e.g., containing refrigerant, a refrigerant mixture, or the like) flows into the compressorfrom the evaporatorin a gaseous state at a relatively lower pressure. The working fluid is oil-free (i.e., does not contain any oil). For example, the refrigerant(s) in the working fluid are used as the lubricant for mechanical components of the refrigerant circuit. Accordingly, the refrigerant circuitand the components disposed therein (e.g., the compressor, expansion devices,, the evaporator, and the like) are oil-free.

The compressorcompresses the gas into a high pressure state, which also heats the gas. The compressorincludes a suction inlet, a discharge outlet, and a compression mechanismconfigured to move within the compressorto compress the gas into the high pressure state. The working fluid flows from the evaporatorinto the suction inletof the compressorand is discharged from the discharge outletof the compressorafter being compressed by the compression mechanism. The working fluid flows from the suction inletinto the compression mechanismand then from the compression mechanismto and out of the compressorthrough the discharge outlet.

The compressormay be, but not limited to, a scroll compressor, a screw compressor, a centrifugal compressor, or the like. In an embodiment, the compressoris a type that utilizes injection of intermediate pressure fluid into the compression mechanism(e.g., economizer injection or the like). In an embodiment, the compressoris a scroll compressor and the compression mechanismis a pair of intermeshed scroll members (e.g., intermediate pressure gaseous working fluid is injected into a formed intermediate compression pocket between the intermeshed scroll members). In an embodiment, the compressoris screw compressor and the compression mechanismis a pair of intermeshed screws (e.g., intermediate pressure gaseous working fluid is injected into a formed intermediate compression pocket between the intermeshed screws). In an embodiment, the compressoris a centrifugal compressor and the compression mechanismis a pair of impellers (e.g., intermediate pressure gaseous working fluid is injected into the fluid flowing from the first impeller to the second impeller within the compressor).