A system for a heat pump that allows the heat pump to work efficiently in extreme cold weathers. The system includes an evaporator in fluid communication with an expansion valve, the expansion valve can receive a liquid refrigerant from a condenser of the heat pump. The evaporator contains a pool of liquid refrigerant and an electric resistance heating source dipped in the pool of liquid refrigerant. The electric resistance heating source can heat the liquid refrigerant of the pool to generate vapors and thus maintaining a desired pressure within the heat pump.

An integrated air conditioning system having a first air conditioning unit having a first evaporator with a first input and a first output; a second air conditioning unit having a second evaporator with a second input and a second output; a first conduit fluidly connecting the first input with the second output; a second conduit fluidly connecting the second input with the first output. The first and second conduits and the first and second evaporators form a working fluid circuit.

A multi-air conditioner for heating/cooling operations, including at least one indoor unit for heating/cooling operations including an indoor heat exchanger; and an outdoor unit for heating/cooling operations including a compressor, an outdoor heat exchanger, and a switching unit configured to be disposed in a discharge side of the compressor to switch a flow of refrigerant. The outdoor unit includes a receiver that selectively stores refrigerant or oil according to a cooling or heating operation mode and provides the stored refrigerant or oil to the compressor. Accordingly, in the accumulator of the multi-air conditioner using the receiver, the receiver which is not used in the heating mode may be converted and used for oil storage, thereby preventing oil burnout without adding structure.

A system for measuring oil circulation ratio in a vapor-compression refrigeration system (VCRS) is provided. The system may include an oil separator configured to receive the refrigerant and oil flow from the low-pressure line of the VCRS and output a oil flow and a refrigerant flow. The system may further include an oil collector configured to receive the separated oil flow provided by the oil separator. A valve may control an oil flow from the oil collector to the low-pressure line. A level sensor may measure oil level in the oil collector. The system may close, in response to the oil being at or less than a first level, the valve to collect oil in the oil collector. The system may open, in response to the oil being at or greater than a second level, the valve to release oil from the oil collector to the low-pressure line.

A refrigeration system for a carbon dioxide based refrigerant fluid, wherein the refrigeration system includes a refrigerant circuit, the refrigerant circuit including a compression device, a heat rejecting heat exchanger, an ejector, a receiver, an expansion device, and a heat absorbing heat exchanger; wherein the ejector includes a primary inlet, a secondary inlet and an outlet; wherein the receiver includes an inlet, a liquid outlet and a gas outlet; wherein the ejector primary inlet is arranged to receive fluid from an outlet of the heat rejecting heat exchanger, the ejector secondary inlet is arranged to receive fluid from an outlet of the heat absorbing heat exchanger, and the ejector outlet is arranged to direct flow to the receiver inlet; wherein a suction inlet of the compression device is arranged to receive refrigerant fluid from the gas outlet of the receiver.

A heat pump that includes a compressing unit having an inlet and an outlet; a condensing unit in fluid communication with the outlet; an evaporating unit in fluid communication with the condensing unit; a variable induction heating unit disposed about a length of conduit fluidically coupling the evaporating unit and the inlet; a reversing valve disposed between the induction heating unit and the evaporating unit; and a metering device (e.g., expansion valve) disposed between the evaporating unit and the condensing unit. Advantageously, the variable induction heating unit may be selectively controllable to enable the heat pump to operate at an ambient temperature of −30 degrees Fahrenheit.

A control method and control device for an electronic expansion valve and an air source heat pump system. The control method includes obtaining a frequency of a compressor, calculating a target exhaust gas temperature according to the frequency, and controlling an opening degree of the electronic expansion valve according to the target exhaust gas temperature; and obtaining an exhaust gas superheat degree of the compressor, and correcting the opening degree of the electronic expansion valve according to a comparison result between the exhaust gas superheat degree and a preset superheat degree value, so that the exhaust gas superheat degree meets superheat degree requirements.

A system for a heat pump that allows the heat pump to work efficiently in extreme cold weathers. The system includes an evaporator influid communication with an expansion valve, the expansion valve can receive a liquid refrigerant from a condenser of the heat pump. The evaporator contains a pool of liquid refrigerant and an electric resistance heating source dipped in the pool of liquid refrigerant. The electric resistance heating source can heat the liquid refrigerant of the pool to generate vapors and thus maintaining a desired pressure within the heat pump.

A heat pump includes a refrigerant loop. The refrigerant loop includes a compressor, a first condenser, a vapor generator having a first region and a second region, a first expansion valve, a second expansion valve, and a first evaporator. A branching point is positioned between the first condenser and the vapor generator. The branching point diverts a portion of a first heat exchange fluid circulating through the refrigerant loop to the vapor generator. The first expansion valve is positioned between the branching point and the vapor generator. An outlet of the vapor generator is coupled to a mid-pressure inlet port of the compressor.

Thermal management systems include an open circuit refrigeration system featuring a first receiver configured to store a gas, a second receiver configured to store a liquid refrigerant fluid, an evaporator configured to extract heat from a heat load that contacts the evaporator, and an exhaust line, where the first receiver, the second receiver, the evaporator, and the exhaust line are connected to provide a refrigerant fluid flow path.