Abstract: A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a suction heat exchanger configured to add heat to working fluid prior to entering the compressor, so as to support the generation of superheat by the HVACR system. The superheat can be controlled to achieve desired levels, so as to support the separation of lubricant from working fluid of the HVACR system. The suction heat exchanger can heat the working fluid passing to the suction of the compressor by exchanging heat with working fluid sourced from between the lubricant separator and the condenser. The suction heat exchanger can further be used as a receiver for controlling the charge of working fluid circulating in the HVACR system.

Abstract: The present disclosure relates to a chiller system comprising: a refrigeration circuit comprising, in flow order, a compressor, a main condenser, an expansion valve and an evaporator; an auxiliary cooling branch configured to receive an auxiliary refrigerant flow from the refrigerant circuit downstream of the compressor, the auxiliary cooling branch bypassing the main condenser, expansion valve and evaporator, the auxiliary branch comprising an auxiliary condenser configured to discharge refrigerant to a cooling line for cooling one or more components of the chiller system; wherein the cooling line is configured to return the portion of refrigerant flow to the refrigeration circuit at or upstream of the compressor; wherein the main condenser and auxiliary condenser are co-located for heat exchange with a common flow of an external heat exchange medium.

Abstract: 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.