Abstract: A sealed induction motor for a chiller assembly is provided. The induction motor includes a stator, a rotor, and a shaft with a first end and a second end. The rotor and the shaft are configured to rotate relative to the stator. The induction motor further includes a first magnetic bearing assembly located proximate the first end of the shaft and a second magnetic bearing assembly located proximate the second end of the shaft. The first and the second magnetic bearing assemblies are configured to support the shaft. The shaft is coupled to a centrifugal compressor using a direct drive connection.

Abstract: Embodiments of the present disclosure relate to a vapor compression system that includes a refrigerant loop, a compressor disposed along the refrigerant loop and configured to circulate refrigerant through the refrigerant loop, a condenser disposed downstream of the compressor along the refrigerant loop and configured to condense vapor refrigerant to liquid refrigerant, a subcooler coupled to the condenser, where the subcooler is external of a shell of the condenser, and where the subcooler is configured to receive the liquid refrigerant from the condenser and to cool the liquid refrigerant to subcooled refrigerant, and an evaporator disposed downstream of the subcooler along the refrigerant loop and configured to evaporate the subcooled refrigerant to the vapor refrigerant.

Abstract: A method of operating a chiller having a closed refrigerant loop including a compressor, a condenser and an evaporator. The refrigerant used in the loop defining a pressure-enthalpy curve representative of different phases (vapor, liquid and vapor, and liquid) of the refrigerant at different combinations of pressure and enthalpy. The loop defining a process cycle (compression, condensation, expansion, and evaporation) of the refrigerant during operation of the loop relative to the pressure-enthalpy curve of the refrigerant. The method including continuously operating the compressor when a segment of the process cycle corresponds to the refrigerant being in the liquid phase.

Abstract: An improved variable geometry diffuser (VGD) mechanism for use with a centrifugal compressor. This VGD mechanism extends substantially completely into the diffuser gap so that the VGD mechanism may be used more fully to control other operational functions. The VGD mechanism may be used to minimize compressor backspin and associated transient loads during compressor shut down by preventing a reverse flow of refrigerant gas through the diffuser gap during compressor shutdown, which is prevented because the diffuser gap is substantially blocked by the full extension of the diffuser ring. During start-up, transient surge and stall also can be effectively eliminated as gas flow through the diffuser gap can be impeded as load and impeller speed increase, thereby alleviating the problems caused by startup loads at low speeds. The VGD mechanism can be used for capacity control as well so as to achieve more effective turndown at low loads.

Abstract: An improved variable geometry diffuser (VGD) mechanism for use with a centrifugal compressor. This VGD mechanism extends substantially completely into the diffuser gap so that the VGD mechanism may be used more fully to control other operational functions. The VGD mechanism may be used to minimize compressor backspin and associated transient loads during compressor shut down by preventing a reverse flow of refrigerant gas through the diffuser gap during compressor shutdown, which is prevented because the diffuser gap is substantially blocked by the full extension of the diffuser ring. During start-up, transient surge and stall also can be effectively eliminated as gas flow through the diffuser gap can be impeded as load and impeller speed increase, thereby alleviating the problems caused by startup loads at low speeds. The VGD mechanism can be used for capacity control as well so as to achieve more effective turndown at low loads.

Abstract: Embodiments of the present disclosure relate to a vapor compression system that includes a refrigerant loop, a compressor disposed along the refrigerant loop and configured to circulate refrigerant through the refrigerant loop, a condenser disposed downstream of the compressor along the refrigerant loop and configured to condense vapor refrigerant to liquid refrigerant, a subcooler coupled to the condenser, where the subcooler is external of a shell of the condenser, and where the subcooler is configured to receive the liquid refrigerant from the condenser and to cool the liquid refrigerant to subcooled refrigerant, and an evaporator disposed downstream of the subcooler along the refrigerant loop and configured to evaporate the subcooled refrigerant to the vapor refrigerant.

Abstract: A heat exchanger for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a shell having an inlet configured to receive refrigerant and an outlet configured to output the refrigerant. The heat exchanger also includes a refrigerant distributor disposed within the shell, and multiple evaporating tubes disposed within the shell and positioned below the refrigerant distributor. The refrigerant distributor includes a perforated plate having multiple holes, each hole extends from a top surface of the perforated plate to a bottom surface of the perforated plate, and a center point of each hole is substantially aligned with a centerline of a respective evaporating tube.

Abstract: A compressor includes an inlet and the inlet includes a flange and an impeller eye. The flange is connected to a suction line that transfers a refrigerant into the compressor via the impeller eye. The refrigerant flows into the compressor with an amount of swirl and a pressure loss. The suction line includes a geometry that includes a constantly decreasing cross-sectional area in a direction towards the compressor. The geometry of the suction line is configured to reduce the amount of swirl and the pressure loss.

Abstract: A method of operating a chiller having a closed refrigerant loop including a compressor, a condenser and an evaporator. The refrigerant used in the loop defining a pressure-enthalpy curve representative of different phases (vapor, liquid and vapor, and liquid) of the refrigerant at different combinations of pressure and enthalpy. The loop defining a process cycle (compression, condensation, expansion, and evaporation) of the refrigerant during operation of the loop relative to the pressure-enthalpy curve of the refrigerant. The method including continuously operating the compressor when a segment of the process cycle corresponds to the refrigerant being in the liquid phase.

Abstract: A method of operating a chiller having a closed refrigerant loop including a compressor, a condenser and an evaporator. The refrigerant used in the loop defining a pressure-enthalpy curve representative of different phases (vapor, liquid and vapor, and liquid) of the refrigerant at different combinations of pressure and enthalpy. The loop defining a process cycle (compression, condensation, expansion, and evaporation) of the refrigerant during operation of the loop relative to the pressure-enthalpy curve of the refrigerant. The method including continuously operating the compressor when a segment of the process cycle corresponds to the refrigerant being in the liquid phase.

Abstract: Embodiments of the present disclosure relate to a vapor compression system that includes a refrigerant loop, a compressor disposed along the refrigerant loop and configured to circulate refrigerant through the refrigerant loop, a condenser disposed downstream of the compressor along the refrigerant loop, where the condenser includes a plurality of tubes disposed in a shell and a diffusion area configured to enhance thermal energy transfer within the condenser, where the diffusion area is defined by a cavity of the condenser without a tube of the plurality of tubes, and an evaporator disposed downstream of the condenser along the refrigerant loop.

Abstract: A sealed induction motor for a chiller assembly is provided. The induction motor includes a stator, a rotor, and a shaft with a first end and a second end. The rotor and the shaft are configured to rotate relative to the stator. The induction motor further includes a first magnetic bearing assembly located proximate the first end of the shaft and a second magnetic bearing assembly located proximate the second end of the shaft. The first and the second magnetic bearing assemblies are configured to support the shaft. The shaft is coupled to a centrifugal compressor using a direct drive connection.

Abstract: A sealed induction motor for a chiller assembly is provided. The induction motor includes a stator, a rotor, and a shaft with a first end and a second end. The rotor and the shaft are configured to rotate relative to the stator. The induction motor further includes a first magnetic bearing assembly located proximate the first end of the shaft and a second magnetic bearing assembly located proximate the second end of the shaft. The first and the second magnetic bearing assemblies are configured to support the shaft. The shaft is coupled to a centrifugal compressor using a direct drive connection.

Abstract: A method of operating a chiller having a closed refrigerant loop including a compressor, a condenser and an evaporator. The refrigerant used in the loop defining a pressure-enthalpy curve representative of different phases (vapor, liquid and vapor, and liquid) of the refrigerant at different combinations of pressure and enthalpy. The loop defining a process cycle (compression, condensation, expansion, and evaporation) of the refrigerant during operation of the loop relative to the pressure-enthalpy curve of the refrigerant. The method including continuously operating the compressor when a segment of the process cycle corresponds to the refrigerant being in the liquid phase.

Abstract: Embodiments of the present disclosure relate to a vapor compression system that includes a refrigerant loop, a compressor disposed along the refrigerant loop and configured to circulate refrigerant through the refrigerant loop, and a heat exchanger disposed along the refrigerant loop and configured to place the refrigerant in a heat exchange relationship with a cooling fluid. The heat exchanger includes a water box portion having a first length, a shell having a second length, a plurality of tubes disposed in the shell and configured to flow the cooling fluid, and a cooling fluid portion having a third length, where the water box portion and the cooling fluid portion are coupled to the shell, such that the first length, the second length, and the third length form a combined length of the heat exchanger that is substantially equal to a target length.

Abstract: An improved variable geometry diffuser (VGD) mechanism for use with a centrifugal compressor. This VGD mechanism extends substantially completely into the diffuser gap so that the VGD mechanism may be used more fully to control other operational functions. The VGD mechanism may be used to minimize compressor backspin and associated transient loads during compressor shut down by preventing a reverse flow of refrigerant gas through the diffuser gap during compressor shutdown, which is prevented because the diffuser gap is substantially blocked by the full extension of the diffuser ring. During start-up, transient surge and stall also can be effectively eliminated as gas flow through the diffuser gap can be impeded as load and impeller speed increase, thereby alleviating the problems caused by startup loads at low speeds. The VGD mechanism can be used for capacity control as well so as to achieve more effective turndown at low loads.

Abstract: A variable speed drive includes a converter connected to an AC power source, a DC link connected to the converter, and an inverter connected to the DC link. The inverter converts DC voltage into an output AC power having a variable voltage and frequency. The inverter includes at least one power electronics module and associated control circuitry; a heat sink in thermal communication with the power electronics module and in fluid communication with a manifold. The manifold includes a tubular member having at least one vertical member portion and at least one horizontal member portion in fluid communication. A plurality of ports conduct cooling fluid into and out of the manifold. A bracket attaches the manifold to a structural frame. Brackets are provided for attachment of power electronics modules to the manifold.

Abstract: A method of operating a chiller having a closed refrigerant loop including a compressor, a condenser and an evaporator. The refrigerant used in the loop defining a pressure-enthalpy curve representative of different phases (vapor, liquid and vapor, and liquid) of the refrigerant at different combinations of pressure and enthalpy. The loop defining a process cycle (compression, condensation, expansion, and evaporation) of the refrigerant during operation of the loop relative to the pressure-enthalpy curve of the refrigerant. The method including continuously operating the compressor when a segment of the process cycle corresponds to the refrigerant being in the liquid phase.

Abstract: An improved variable geometry diffuser (VGD) mechanism for use with a centrifugal compressor. This VGD mechanism extends substantially completely into the diffuser gap so that the VGD mechanism may be used more fully to control other operational functions. The VGD mechanism may be used to minimize compressor backspin and associated transient loads during compressor shut down by preventing a reverse flow of refrigerant gas through the diffuser gap during compressor shutdown, which is prevented because the diffuser gap is substantially blocked by the full extension of the diffuser ring. During start-up, transient surge and stall also can be effectively eliminated as gas flow through the diffuser gap can be impeded as load and impeller speed increase, thereby alleviating the problems caused by startup loads at low speeds. The VGD mechanism can be used for capacity control as well so as to achieve more effective turndown at low loads.

Abstract: A compressor includes an inlet and the inlet includes a flange and an impeller eye. The flange is connected to a suction line that transfers a refrigerant into the compressor via the impeller eye. The refrigerant flows into the compressor with an amount of swirl and a pressure loss. The suction line includes a geometry that includes a constantly decreasing cross-sectional area in a direction towards the compressor. The geometry of the suction line is configured to reduce the amount of swirl and the pressure loss.