A packaged, pumped liquid, recirculating refrigeration system with charges of 10 lbs or less of refrigerant per ton of refrigeration capacity. The compressor and related components are situated in a pre-packaged modular machine room, and in which the condenser is mounted on the machine room and the evaporator is close coupled to the pre-packaged modular machine room. Prior art large receiver vessels may be replaced with a single or dual phase cyclonic separator also housed in the pre-packaged modular machine room.

Methods, systems, and apparatuses are described to help manage oil return such as in a chiller system of a HVAC system. A refrigerant/oil mixture can be directed out of the evaporator into an oil return heat exchanger that is configured to help vaporize a refrigerant portion of the refrigerant/oil mixture. Superheat refrigerant vapor can be directed from a condenser into the oil return heat exchanger as the heat energy to vaporize the refrigerant portion in the refrigerant/oil mixture. The oil return heat exchanger can be positioned lower than the evaporator so that gravity can help the refrigerant/oil mixture to flow into the oil return heat exchanger.

A refrigerant recovery system includes a first oil separator including a chamber configured to receive refrigerant from an air conditioning system, a heat exchanger disposed within the first oil separator, and a compressor fluidly connected to the chamber and the heat exchanger. A first valve is disposed in a first flow line that is fluidly connected between an inlet of the first oil separator and a source of refrigerant and a second valve is disposed in a second flow line that fluidly connects the compressor and the heat exchanger. A controller is configured to open the first valve to enable refrigerant to pass into the chamber of the first oil separator, open the second valve so that a flow loop for refrigerant is formed between the heat exchanger and the compressor, activate the compressor to heat the refrigerant flowing through the flow loop, and subsequently commence a refrigerant recovery operation.

In a case of a heating operation in which the use side heat exchanger functions as a condenser when an outside temperature is a predetermined low temperature, a low-outside-temperature heating operation start-up mode in which, while a refrigerant discharged from the compressor is caused to flow into the use side heat exchanger, a refrigerant is supplied to the injection port of the compressor via the injection pipe and part of the refrigerant that has transferred heat in the heat source side heat exchanger is supplied to the compressor, is followed by a low-outside-temperature heating operation mode in which the refrigerant discharged from the compressor is supplied to the injection port of the compressor via the injection pipe while the refrigerant being caused to flow into the use side heat exchanger.

A refrigeration system includes a refrigeration circuit and a coolant circuit separate from the refrigeration circuit. The refrigerant circuit includes a gas cooler/condenser, a receiver, and an evaporator. The coolant circuit includes a heat exchanger configured to transfer heat from a refrigerant circulating within the refrigeration circuit into a coolant circulating within the coolant circuit, a heat sink configured to remove heat from the coolant circulating within the coolant circuit, and a magnetocaloric conditioning unit configured to transfer heat from the coolant within a first fluid conduit of the coolant circuit into the coolant within a second fluid conduit of the coolant circuit. The first fluid conduit connects an outlet of the heat exchanger to an inlet of the heat sink, whereas the second fluid conduit connects an outlet of the heat sink to an inlet of the heat exchanger.

A compressor assembly, a vapor compression system incorporating the same, and a method for operating the vapor compression system are provided. The compressor assembly includes a motor for driving a rotating shaft, a foil bearing for supporting the rotating shaft, a compression mechanism for increasing the pressure of a working fluid, a supply line in fluid communication with the compression mechanism, and a heating apparatus for heating the working fluid. The supply line is configured for injecting the working fluid (e.g., from downstream of the compression mechanism) toward the foil bearing. The method provides for the monitoring of the temperature of the working fluid. When the temperature of the working fluid is less than 3° F. of superheat it is heated prior to being injected toward the foil bearing. The heating of the working fluid prevents, or at least mitigates, liquid from being transferred to the foil bearing.

A wind powered cooling system, including a windmill including a transmission rotatably coupled to at least one vane, wherein wind moving past the vane causes the vane to rotate and transmit rotational energy to the transmission; and a cooling system including: a compressor system including a compressor mechanically coupled to the transmission, the compressor including a first member for translating rotational energy of the transmission to movement of the first member with respect to a second member so as to compress a refrigerant fluid stored therein; and an evaporator system including an evaporator in fluid communication with the compressor for expanding and evaporating compressed refrigerant fluid into cold refrigerant gas, wherein the cold refrigerant gas cools air surrounding the evaporator system by convection.

An air conditioning system includes a main circuit having a multi-stage compressor, a condenser, a throttling element and an evaporator connected by pipelines; and a cooling branch, the inlet of which is connected to the main circuit between the condenser and the throttling element, and the outlet of which is connected to at least one of the first-stage suction port and the intermediate-stage suction port of the multi-stage compressor, wherein the cooling branch flows through the drive motor of the multi-stage compressor, and a regulating valve for controlling the opening of the cooling branch is provided on the cooling branch; and a control module that controls the opening of the regulating valve on the cooling branch based on the temperature of the outlet downstream of the drive motor on the cooling branch and the intermediate suction pressure of the intermediate-stage suction port of the multi-stage compressor.

A packaged, pumped liquid, recirculating refrigeration system with charges of 10 lbs or less of refrigerant per ton of refrigeration capacity. The compressor and related components are situated in a pre-packaged modular machine room, and in which the condenser is mounted on the machine room and the evaporator is close coupled to the pre-packaged modular machine room. Prior art large receiver vessels may be replaced with a single or dual phase cyclonic separator also housed in the pre-packaged modular machine room.

Embodiments of the present invention reduce the amount of energy required to operate air-conditioners and refrigerators by providing a vapor-compression system that harnesses a low- or no-cost source of energy, namely, heat, and uses the harnessed heat to power a new kind of compressor, called a “burst compressor” and a new kind of pump, called a “vapor pump.” The heat-driven burst compressor pressurizes the refrigerant, while also providing “push and pull” vapor refrigerant to the vapor pump. The vapor pump, actuated by the high pressure refrigerant in gaseous form provided by the burst compressor, is configured to pump a combination of gaseous, vaporous and liquid refrigerant out of the receiver tank and inject that low pressure refrigerant mix into the burst compressor, where it is heated to change the state of the refrigerant to a heated, pressurized gas. Then the heated, pressurized gas is released in bursts into the other components of the vapor compression cycle. Thus, embodiments of the present invention use heat to provide cold. Because of this arrangement, vapor-compression systems constructed and arranged to operate according to embodiments of the present invention are able to provide air-conditioning and/or refrigeration much more efficiently and with much less expense than traditional vapor compression systems for air-conditioning and refrigeration.