Abstract: A condenser includes a shell defining an inner volume configured to receive and discharge a refrigerant, a condensing section disposed within the shell, where the condensing section includes a plurality of tubes configured to circulate cooling fluid therethrough, and a subcooler disposed within the shell and configured to receive the refrigerant from the condensing section. The subcooler includes a first pass having a first set of tubes configured to circulate cooling fluid therethrough, a second pass having a second set of tubes configured to circulate cooling fluid therethrough, where the second pass is disposed downstream of the first pass relative to a flow of refrigerant through the subcooler, and a separation plate disposed between the first set of tubes and the second set of tubes.

Abstract: A vapor compression system includes a heat exchanger configured to facilitate heat transfer between a refrigerant and a conditioning fluid. The vapor compression system also includes an expansion valve disposed along a conduit coupled to the heat exchanger. The conduit is configured to direct a flow of the refrigerant into the heat exchanger. Additionally, the vapor compression system includes a sensor configured to provide feedback indicative of a temperature of the conditioning fluid exiting the heat exchanger and a controller including a memory and processing circuitry. The processing circuitry is configured to receive a signal indicative of the temperature of the conditioning fluid exiting the heat exchanger from the sensor and adjust operation of the expansion valve based on the signal.

Abstract: A heat exchanger for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a base portion having a first plurality of channels extending therethrough and a second plurality of channels extending therethrough. The heat exchanger further includes a first manifold and a second manifold, where the first plurality of channels extends from the first manifold to the second manifold, and a third manifold and a fourth manifold, where the second plurality of channels extends from the third manifold to the fourth manifold. The heat exchanger further includes a single part having the base portion, the first manifold, the second manifold, the third manifold, and the fourth manifold.

Abstract: A heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes a refrigerant circuit configured to flow a refrigerant therethrough, a sump configured to direct a lubricant to a compressor, an ejector configured to direct the lubricant from the refrigerant circuit to the sump, and an expansion device configured to reduce a pressure of the refrigerant directed through the refrigerant circuit. The HVAC&R system further includes a controller configured to instruct the expansion device to adjust to a first position to enable the ejector to direct lubricant from the refrigerant circuit to the sump at a first target flow rate in a first mode, and the controller is configured to instruct the expansion device to adjust to a second position to enable the ejector to direct lubricant from the refrigerant circuit to the sump at a second target flow rate in a second mode.

Abstract: A vapor compression system includes a compressor configured to circulate a refrigerant through a refrigerant loop, a sump configured to receive a mixture of lubricant and the refrigerant from the compressor, and a controller having a memory and a processor. The processor is configured to receive a first signal indicative of a temperature of the mixture within the sump, receive a second signal indicative of a pressure of the mixture within the sump, determine a relative amount of the refrigerant in the mixture based on the first signal and the second signal, and output a control signal in response to the relative amount of the refrigerant in the mixture exceeding a threshold value.

Abstract: A system for reducing the refrigerant pressure in an oil sump or in a cavity of a housing. The invention is particularly useful for reducing pressure in a compressor for heat pump applications that has been validated for water chiller operations or in turbine and generator systems in ORC systems generating electricity using refrigerant, the ORC systems essentially being a heat pump application operating in reverse. An auxiliary compressor, an auxiliary condenser or an ejector pump may be used to reduce pressure in the oil sump, to separate refrigerant from oil. The auxiliary compressor, the auxiliary condenser or the ejector pump may also be used to reduce the pressure of refrigerant in the housing of a compressor in heat pump applications at temperatures and pressures at which the compressor was validated for water chiller applications and of the turbine and generator in ORC applications.

Abstract: A system for reducing the refrigerant pressure in an oil sump (10) or in a cavity (352) of a housing. The invention is particularly useful for reducing pressure in a compressor (23) for heat pump applications that has been validated for water chiller operations or in turbine and generator systems in ORC systems generating electricity using refrigerant, the ORC systems essentially being a heat pump application operating in reverse. An auxiliary compressor (509), an auxiliary condenser (709) or an ejector pump (609) may be used to reduce pressure in the oil sump (10), to separate refrigerant from oil. The auxiliary compressor (509), the auxiliary condenser (709) or the ejector pump (609) may also be used to reduce the pressure of refrigerant in the housing of a compressor in heat pump applications at temperatures and pressures at which the compressor was validated for water chiller applications and of the turbine and generator in ORC applications.

Abstract: A system for reducing the refrigerant pressure in an oil sump (10) or in a cavity (352) of a housing. The invention is particularly useful for reducing pressure in a compressor (23) for heat pump applications that has been validated for water chiller operations or in turbine and generator systems in ORC systems generating electricity using refrigerant, the ORC systems essentially being a heat pump application operating in reverse. An auxiliary compressor (509), an auxiliary condenser (709) or an ejector pump (609) may be used to reduce pressure in the oil sump (10), to separate refrigerant from oil. The auxiliary compressor (509), the auxiliary condenser (709) or the ejector pump (609) may also be used to reduce the pressure of refrigerant in the housing of a compressor in heat pump applications at temperatures and pressures at which the compressor was validated for water chiller applications and of the turbine and generator in ORC applications.

Abstract: A method for controlling multi-stage centrifugal compressors is provided. The method includes, for each stage of the compressor, defining a Mach ratio and impeller diameter, calculating a minimum required motor drive frequency to operate free from surge conditions for a current head factor and flow reduction device position, and adjusting the flow reduction device position while maintaining an actual motor drive frequency at a acceptable level to achieve a leaving chilled water temperature set point. The method also includes measuring a suction pressure and a discharge pressure and calculating a saturated suction temperature and a saturated discharge temperature for each stage of the compressor. The method further includes calculating an actual minimum motor drive frequency that is the greater of a first actual minimum motor drive frequency and a second actual minimum motor drive frequency associated with a first compressor stage and a second compressor stage of the compressor, respectively.

Abstract: A method for controlling multi-stage centrifugal compressors is provided. It allows an optimization of compressor head and efficiency at each compression stage and is specifically valuable at reduced compressor flow.

Abstract: A cooling system provided for a motor powering a compressor in a vapor compression system. The cooling system includes a housing enclosing the motor and a cavity located within the housing. A fluid circuit has a first connection with the housing configured to provide a liquid or two phase cooling fluid to the motor. The two phase cooling fluid is separable into a vapor phase portion and a liquid phase portion. The fluid circuit further has a second connection with the housing to remove cooling fluid in fluid communication with the fluid circuit. The cooling fluid conveyed through the second connection is two phase cooling fluid. The fluid circuit further has a third connection with the housing for receiving and circulating in the cavity the vapor phase portion conveyed through the second connection.

Abstract: A system for reducing the refrigerant pressure in an oil sump (10) or in a cavity (352) of a housing. The invention is particularly useful for reducing pressure in a compressor (23) for heat pump applications that has been validated for water chiller operations or in turbine and generator systems in ORC systems generating electricity using refrigerant, the ORC systems essentially being a heat pump application operating in reverse. An auxiliary compressor (509), an auxiliary condenser (709) or an ejector pump (609) may be used to reduce pressure in the oil sump (10), to separate refrigerant from oil. The auxiliary compressor (509), the auxiliary condenser (709) or the ejector pump (609) may also be used to reduce the pressure of refrigerant in the housing of a compressor in heat pump applications at temperatures and pressures at which the compressor was validated for water chiller applications and of the turbine and generator in ORC applications.

Abstract: A cooling system provided for a motor powering a compressor in a vapor compression system. The cooling system includes a housing enclosing the motor and a cavity located within the housing. A fluid circuit has a first connection with the housing configured to provide a liquid or two phase cooling fluid to the motor. The two phase cooling fluid is separable into a vapor phase portion and a liquid phase portion. The fluid circuit further has a second connection with the housing to remove cooling fluid in fluid communication with the fluid circuit. The cooling fluid conveyed through the second connection is two phase cooling fluid. The fluid circuit further has a third connection with the housing for receiving and circulating in the cavity the vapor phase portion conveyed through the second connection.

Abstract: Apparatus and method for determining the clearance and wear of mechanical back-up bearings of turbomachinery utilizing electromagnetic bearings. In order to reduce the prospects of catastrophic failure during a shut-down or loss of electrical power, a rotating apparatus utilizes the electromagnetic bearings to manipulate the shaft to measure the clearance of the mechanical back-up bearings. When power is restored, a programmable controller provides power to the electromagnetic bearings to automatically move the shaft in accordance with a predetermined sequence to contact the mechanical back-up bearings to determine the clearance of the mechanical back-up bearings. These values are stored in the controller memory. The measured clearance is compared to prior clearance measurements of the mechanical back-up bearings to determine the wear of the back-up bearings. The actual wear is compared to the allowable wear for the bearings. If actual wear exceeds a predetermined value, a warning is generated.