A refrigeration system includes a compressor for compressing a refrigerant, a condenser for cooling the refrigerant, an evaporator for heating the refrigerant, and a lubrication system for providing a lubricant mist to a movable component of the compressor. The lubrication system includes an ejector arranged in fluid communication with the compressor and the evaporator, wherein the lubricant mist is carried by the refrigerant to the movable component.

A method of lubricant management in a heating ventilation and air conditioning (HVAC) system includes flowing a volume of a compressor lubricant and refrigerant mixture from an evaporator into a lubricant still and stopping the flow of the compressor lubricant and refrigerant mixture into the lubricant still when the mixture fills the lubricant still to a selected level. Compressor lubricant is distilled from the mixture via a thermal energy exchange, and the distillation is stopped when a concentration of compressor lubricant in the lubricant still exceeds a predetermined concentration level. The distillate is urged from the lubricant still.

A turbo refrigerator is provided with: a turbo compressor having a motor; an oil cooling unit which cools lubricating oil which is supplied to at least a portion of the turbo compressor; a refrigerant introduction part which introduces some of the refrigerant which circulates between an evaporator and a condenser into a motor accommodation space and the oil cooling unit; and a cooling unit which cools the refrigerant which is introduced into the motor accommodation space and the oil cooling unit.

A cascade refrigeration system includes an upper portion. The upper portion includes at least one modular chiller unit that provides cooling to at least one of a low temperature subsystem having a plurality of low temperature loads, and a medium temperature subsystem having a plurality of medium temperature loads. The modular chiller unit includes a refrigerant circuit, an ammonia refrigerant, an ammonia refrigerant accumulator, and an oil separation system. The refrigerant circuit includes at least a compressor, a condenser, an expansion device, and an evaporator. The ammonia refrigerant is configured for circulation within the refrigerant circuit. The ammonia refrigerant accumulator is configured to receive the ammonia refrigerant from the evaporator. The oil separation system is configured to remove oil from the ammonia refrigerant. The oil separation system includes an oil separator that is configured to remove oil from the ammonia refrigerant flowing from the compressor to the condenser, an oil drain pot that is configured to collect oil from the evaporator, and an oil reservoir that is configured to collect oil from the oil separator and the oil drain pot.

A flooded central air conditioning system includes a compressor, condenser, external oil separator, low pressure circulation barrel and spiral evaporator, refrigerant outlet of compressor connects to refrigerant inlet of external oil separator, whose refrigerant outlet connects to condenser inlet, whose outlet connects to refrigerant inlet of low pressure circulation barrel, whose refrigerant outlet connects to refrigerant inlet of spiral evaporator, whose refrigerant outlet connects to gas inlet of low pressure circulation barrel, whose gas outlet connects to refrigerant inlet of compressor. The present invention provides a flooded central air conditioning system, which owns advantages of energy saving and better refrigeration as ammonia refrigerant, safety and convenience as Freon refrigerant, has greatly improved the refrigeration efficient of refrigeration system using Freon as refrigerant. Integrated energy efficiency is significantly improved, and energy consumption greatly reduced. The central air conditioning system described owns pretty strong market competitiveness.

A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes an evaporator disposed along a working fluid circuit, where the evaporator is configured to transfer heat between a working fluid and a conditioning fluid, and a lubricant separation system. The lubricant separation system includes a lubricant separation heat exchanger configured to receive a mixture of the working fluid and a lubricant from the evaporator and to transfer heat from a flow of heated fluid to the mixture to separate the working fluid from the lubricant. The lubricant separation system is also configured to direct the working fluid separated from the lubricant to the evaporator.