Abstract: A lubricant supply system is for a compressor that compresses a first working fluid in a heat transfer circuit. The lubricant supply system includes a lubricant tank, a lubricant pathway for supplying lubricant from the lubricant tank to one or more bearings of the compressor, and a lubricant refrigeration system with a lubricant heater and a lubricant cooler. The lubricant heater configured to heat the lubricant discharged from the one or more bearings and the lubricant cooler configured to cool the lubricant flowing through the lubricant pathway. A method of lubricating a compressor includes heating the lubricant, directing the lubricant from a lubricant tank through a lubricant pathway to one or more bearings of the compressor, and cooling the lubricant passing through the lubricant pathway.

Abstract: Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a throttle ring disposed between stages of the compressor. The throttle ring can allow or obstruct flow through the side stream injection port. The throttle ring can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. A method of operating a centrifugal compressor can include actuating a throttle ring by rotating a drive ring to adjust a flow of interstage fluid into the second stage impeller.

Abstract: An interstage throttle for a centrifugal compressor includes a flow guide plate, a throttle ring, a drive ring, and linkage assemblies. The flow guide plate includes guide vanes that form channels that direct working fluid in between stages of the compressor. The linkage assemblies connect the drive ring to the throttle ring such that rotation of the drive ring moves the throttle ring in an axial direction. Teeth of the throttle ring partially block the channels when the throttle ring is in an extended position. A method of operating a centrifugal compressor includes directing the working fluid discharged from the first stage to a second stage via channels in a interstage throttle. A centrifugal compressor includes a first stage with a first impeller, a second stage with a second impeller, and an interstage throttle fluidly connecting the first stage to the second stage.

Abstract: A lubricant supply system is for a compressor that compresses a first working fluid in a heat transfer circuit. The lubricant supply system includes a lubricant tank, a lubricant pathway for supplying lubricant from the lubricant tank to one or more bearings of the compressor, and a lubricant refrigeration system with a lubricant heater and a lubricant cooler. The lubricant heater configured to heat the lubricant discharged from the one or more bearings and the lubricant cooler configured to cool the lubricant flowing through the lubricant pathway. A method of lubricating a compressor includes heating the lubricant, directing the lubricant from a lubricant tank through a lubricant pathway to one or more bearings of the compressor, and cooling the lubricant passing through the lubricant pathway.

Abstract: Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a capacity control valve that has a curved surface facing a flow of refrigerant from the first stage to the second stage. The capacity control valve can allow or obstruct flow through the side stream injection port. The capacity control valve can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. The side stream injection port and the capacity control valve can be ring-shaped. The side stream injection port and the capacity control valve can allow at least some of the side stream to be introduced on a side of the capacity control valve opposite the curved surface.

Abstract: An interstage throttle for a centrifugal compressor includes a flow guide plate, a throttle ring, a drive ring, and linkage assemblies. The flow guide plate includes guide vanes that form channels that direct working fluid in between stages of the compressor. The linkage assemblies connect the drive ring to the throttle ring such that rotation of the drive ring moves the throttle ring in an axial direction. Teeth of the throttle ring partially block the channels when the throttle ring is in an extended position. A method of operating a centrifugal compressor includes directing the working fluid discharged from the first stage to a second stage via channels in a interstage throttle. A centrifugal compressor includes a first stage with a first impeller, a second stage with a second impeller, and an interstage throttle fluidly connecting the first stage to the second stage.

Abstract: Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a throttle ring disposed between stages of the compressor. The throttle ring can allow or obstruct flow through the side stream injection port. The throttle ring can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. A method of operating a centrifugal compressor can include actuating a throttle ring by rotating a drive ring to adjust a flow of interstage fluid into the second stage impeller.

Abstract: Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a throttle ring disposed between stages of the compressor. The throttle ring can allow or obstruct flow through the side stream injection port. The throttle ring can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. A method of operating a centrifugal compressor can include actuating a throttle ring by rotating a drive ring to adjust a flow of interstage fluid into the second stage impeller.

Abstract: Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a capacity control valve that has a curved surface facing a flow of refrigerant from the first stage to the second stage. The capacity control valve can allow or obstruct flow through the side stream injection port. The capacity control valve can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. The side stream injection port and the capacity control valve can be ring-shaped. The side stream injection port and the capacity control valve can allow at least some of the side stream to be introduced on a side of the capacity control valve opposite the curved surface.

Abstract: Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a capacity control valve that has a curved surface facing a flow of refrigerant from the first stage to the second stage. The capacity control valve can allow or obstruct flow through the side stream injection port. The capacity control valve can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. The side stream injection port and the capacity control valve can be ring-shaped. The side stream injection port and the capacity control valve can allow at least some of the side stream to be introduced on a side of the capacity control valve opposite the curved surface.

Abstract: Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a throttle ring disposed between stages of the compressor. The throttle ring can allow or obstruct flow through the side stream injection port. The throttle ring can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. A method of operating a centrifugal compressor can include actuating a throttle ring by rotating a drive ring to adjust a flow of interstage fluid into the second stage impeller.

Abstract: Systems and methods to clamp an impeller on a shaft in a centrifugal compressor. The embodiments as disclosed herein may include clamping individual impeller independently to the shaft, which may reduce the tolerance stack-up effect of a plurality of impellers. The impeller can be clamped to the shaft by positioning, for example, a relatively stiff support (e.g. a shaft locknut) on a front side of the impeller. The impeller can also be clamped to the shaft by a relatively flexible support to compensate for e.g. thermal expansion/contraction of the impeller. The embodiments as disclosed herein are particularly suitable for a multi-stage impeller.

Abstract: Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a capacity control valve that has a curved surface facing a flow of refrigerant from the first stage to the second stage. The capacity control valve can allow or obstruct flow through the side stream injection port. The capacity control valve can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. The side stream injection port and the capacity control valve can be ring-shaped. The side stream injection port and the capacity control valve can allow at least some of the side stream to be introduced on a side of the capacity control valve opposite the curved surface.

Abstract: Systems and methods to clamp an impeller on a shaft in a centrifugal compressor. The embodiments as disclosed herein may include clamping individual impeller independently to the shaft, which may reduce the tolerance stack-up effect of a plurality of impellers. The impeller can be clamped to the shaft by positioning, for example, a relatively stiff support (e.g. a shaft locknut) on a front side of the impeller. The impeller can also be clamped to the shaft by a relatively flexible support to compensate for e.g. thermal expansion/contraction of the impeller. The embodiments as disclosed herein are particularly suitable for a multi-stage impeller.

Abstract: Systems and methods to help provide lubricant to a bearing in a compressor are disclosed. The embodiments disclosed herein generally are directed to systems and methods to provide a lubricant flow to the bearing, where the lubricant flow relies on the rotation of a shaft of the compressor, so that the lubricant flow can be independent of a power supply.

Abstract: Systems and methods to clamp an impeller on a shaft in a centrifugal compressor. The embodiments as disclosed herein may include clamping individual impeller independently to the shaft, which may reduce the tolerance stack-up effect of a plurality of impellers. The impeller can be clamped to the shaft by positioning, for example, a relatively stiff support (e.g. a shaft locknut) on a front side of the impeller. The impeller can also be clamped to the shaft by a relatively flexible support to compensate for e.g. thermal expansion/contraction of the impeller. The embodiments as disclosed herein are particularly suitable for a multi-stage impeller.

Abstract: A lubricant separator is disclosed. The lubricant separator can cause lubricant which is entrained with a heat transfer fluid (e.g., a lubricant—heat transfer fluid mixture) to coalesce and fall (e.g., via gravity) into a bottom portion of a lubricant tank assembly. The lubricant separator can also reduce a velocity of the lubricant—heat transfer fluid mixture as it enters the lubricant tank assembly. The velocity reduction can, for example, reduce an amount of splashing of the lubricant that occurs as the lubricant—heat transfer fluid mixture enters the lubricant tank assembly. The velocity reduction can also, for example, be relatively more conducive to lubricant droplets falling into the bottom portion of the lubricant tank assembly as the flow of the heat transfer fluid is provided to a heat transfer fluid return conduit of the lubricant tank assembly.

Abstract: Systems and methods to help provide lubricant to a bearing in a compressor are disclosed. The embodiments disclosed herein generally are directed to systems and methods to provide a lubricant flow to the bearing, where the lubricant flow relies on the rotation of a shaft of the compressor, so that the lubricant flow can be independent of a power supply.

Abstract: A sealing joint for a compressor casing, such as a compressor casing for a centrifugal compressor of a chiller, is provided. The sealing joint may be configured to have a first cover and a second cover. A first mating surface of the first cover may have an inner annular portion surrounding an inner cavity of the sealing joint, and an outer annular portion. The inner annular portion may be positioned between the inner cavity of the compressor casing and the outer annular portion. A sealant may be applied to the sealing joint, and a depth of the sealant on the inner annular portion may be deeper than a depth of the sealant on the outer annular portion. The depth of the sealant on the inner annular portion may help the sealing joint tolerate more elongation range without a sealant failure than a regular casing.

Abstract: A lubricant separator is disclosed. The lubricant separator can cause lubricant which is entrained with a heat transfer fluid (e.g., a lubricant—heat transfer fluid mixture) to coalesce and fall (e.g., via gravity) into a bottom portion of a lubricant tank assembly. The lubricant separator can also reduce a velocity of the lubricant—heat transfer fluid mixture as it enters the lubricant tank assembly. The velocity reduction can, for example, reduce an amount of splashing of the lubricant that occurs as the lubricant—heat transfer fluid mixture enters the lubricant tank assembly. The velocity reduction can also, for example, be relatively more conducive to lubricant droplets falling into the bottom portion of the lubricant tank assembly as the flow of the heat transfer fluid is provided to a heat transfer fluid return conduit of the lubricant tank assembly.