Systems and methods for lubricant management of a compressor in an HVACR system are disclosed. A heat transfer circuit can utilize a working fluid to provide heating or cooling includes a compressor for compressing the working fluid and a heat source configured to increase a suction temperature of the working fluid entering the compressor. One or more lubricant rheological properties in a compressor system based on measurements taken at or near a bearing cavity of the compressor are determinable. A lubricant reservoir can be in thermal communication with a discharge flow path of the compressor. An internal heat exchanger can be disposed within a compressor for improving viscosity of the lubricant to be cycled back into the compressor. A heater can be located on a fluid line between a lubricant separator and a lubricant inlet. Condenser fans can be controlled.

Embodiments include techniques for generating coordination maps for energy efficient chilled water and condenser water temperature resets in a chiller plant system. The embodiments include a controller configured to control and set thresholds for one or more parameters of the chiller system, wherein the chiller system includes one or more cooling tower, one or more pumps, and one or more water chillers, and one or more sensors operably coupled to the controller, wherein the one or more sensors are configured to measure values for one or more parameters. The embodiments also include a processor coupled to the controller, wherein the processor is configured to generate a coordination map based on the measured values and the thresholds for the one or more parameters, configure an operating setpoint for the chiller system based on the coordination map, and control the chiller system based at least in part on the configured operating setpoint.

Embodiments include techniques for generating coordination maps for energy efficient chilled water and condenser water temperature resets in a chiller plant system. The embodiments include a controller configured to control and set thresholds for one or more parameters of the chiller system, wherein the chiller system includes one or more cooling tower, one or more pumps, and one or more water chillers, and one or more sensors operably coupled to the controller, wherein the one or more sensors are configured to measure values for one or more parameters. The embodiments also include a processor coupled to the controller, wherein the processor is configured to generate a coordination map based on the measured values and the thresholds for the one or more parameters, configure an operating setpoint for the chiller system based on the coordination map, and control the chiller system based at least in part on the configured operating setpoint.

A refrigeration cycle apparatus includes a refrigerant and a refrigeration cycle circuit. The refrigeration cycle circuit includes a compressor, and causes the refrigerant to circulate therethrough. The refrigerant is HFO-based refrigerant alone or a mixed refrigerant. In the mixed refrigerant, a mixing ratio of HFO-based refrigerant is equal to or more than 10% by weight. The compressor includes a motor. The motor includes a portion formed from a resin component. The resin component is made of PET, PA, or the like.

A refrigeration cycle apparatus includes a refrigerant and a refrigeration cycle circuit. The refrigeration cycle circuit includes a compressor, and causes the refrigerant to circulate therethrough. The refrigerant is HFO-based refrigerant alone or a mixed refrigerant. In the mixed refrigerant, a mixing ratio of HFO-based refrigerant is equal to or more than 10% by weight. The compressor includes a motor. The motor includes a portion formed from a resin component. The resin component is made of PET, PA, or the like.

Compressor systems for compression of refrigerant fluid are described. The compressor systems include first and second compressor elements each having a housing. An equalization line fluidly connects the first and second housings at suction sides in order to allow for equalization of pressure between the housings as well as flow of lubricant between the housings. An equalization valve on the equalization line is used to open and close the connection between the first and second compressor element housings. The compressor system is arranged for full load operation using both the first and second compressor elements as well as for part load operation in which one of the compressor elements is not utilized. The equalization valve is opened during full load operation and is closed during part load operation to thereby prevent movement of lubricant and/or refrigerant fluid between the first and second compressor element housings during part load operation.

A compressor system includes a screw compressor and a controller. The screw compressor includes a slide valve selectively actuatable between a first position and a second position to facilitate modulating a capacity of the screw compressor between fully-loaded and fully-unloaded. The controller is communicably coupled to the slide valve. The controller is configured to receive a chilled fluid temperature setpoint for a fluid in heat transfer communication with a refrigerant of the refrigeration circuit; receive temperature data indicative of a chilled fluid temperature of the fluid; determine a difference between the chilled fluid temperature and the chilled fluid temperature setpoint; and provide one of a load command and an unload command to the slide valve based the difference between the chilled fluid temperature and the chilled fluid temperature setpoint. According to an embodiment, the controller does not receive feedback from the screw compressor regarding a position of the slide valve.

A compressor system is provided that includes a contact cooled compressor and a coolant separator. The coolant separator is used to remove coolant fluid from a compressed flow stream produced by the contact cooled compressor during its operation. The coolant separator routes the removed coolant fluid back to the contact cooled compressor for further use. In some forms the coolant fluid is cooled prior to delivery back to the compressor. A stop valve can be provided in the coolant fluid return line to halt the flow of the fluid. A pressure sensitive member can be disposed to sense pressure of the coolant fluid that has been routed past the stop valve. Operation of the compressor can be changed as a result of the sensed pressure from the pressure sensitive member. Information from a temperature sensitive member can also be used to change operation of the compressor.

A compressor system is provided that includes a contact cooled compressor and a coolant separator. The coolant separator is used to remove coolant fluid from a compressed flow stream produced by the contact cooled compressor during its operation. The coolant separator routes the removed coolant fluid back to the contact cooled compressor for further use. In some forms the coolant fluid is cooled prior to delivery back to the compressor. A stop valve can be provided in the coolant fluid return line to halt the flow of the fluid. A pressure sensitive member can be disposed to sense pressure of the coolant fluid that has been routed past the stop valve. Operation of the compressor can be changed as a result of the sensed pressure from the pressure sensitive member. Information from a temperature sensitive member can also be used to change operation of the compressor.

A heating, ventilation, air conditioning, and refrigeration (HVACR) system is disclosed. The HVACR system includes a refrigerant circuit. The refrigerant circuit includes a compressor, a condenser, an expansion device, and an evaporator fluidly connected. A controller is electronically connected to the compressor. The controller is configured to prevent the compressor from operating at a speed that is less than a minimum speed limit. A lubricant separator has an inlet fluidly connected between the compressor and the condenser and a plurality of outlets. A first of the plurality of outlets is fluidly connected to the condenser. A second of the plurality of outlets is fluidly connected to one or more components of the compressor to provide a lubricant to the one or more components.