An air-conditioning apparatus that includes a compressor, a flow switching device, an outdoor heat exchange unit, an expansion section and an indoor heat exchanger, which are connected by pipes, in which the outdoor heat exchange unit includes a first outdoor heat exchanger, a first flow rate control device, a second outdoor heat exchanger, a second flow rate control device, a bypass pipe, the second outdoor heat exchanger, the second flow rate control device, a third flow rate control device, and a flow control device.

Provided is a refrigerant cycle apparatus capable of suppressing detects caused by iodine even when a refrigerant containing iodine is used. An air conditioner includes a refrigerant circuit through which a refrigerant containing iodine circulates. The refrigerant circuit includes a component that is in contact with a refrigerant containing iodine, the component being made of metal other than aluminum or an aluminum alloy, or having a content of aluminum which is equal to or less than a ratio at which corrosion of aluminum occurs by iodine. The component is at least one of a component of a compressor, a component of a heat-source-side heat exchanger or a utilization-side heat exchanger, a component of an expansion valve, a drier, and a connection pipe.

The disclosure describes a system that includes an evaporator, an accumulator downstream of the evaporator, a centrifugal compressor downstream of the accumulator, a first heat exchanger stage downstream of the centrifugal compressor, and a second heat exchanger stage downstream of the first heat exchanger stage. The evaporator is configured to cool a conditioned air stream using a refrigerant. The accumulator is configured to store excess refrigerant. The centrifugal compressor is configured to compress the refrigerant. The first heat exchanger stage is configured to cool the refrigerant using environmental air. The second heat exchanger stage is configured to cool the refrigerant from the first heat exchanger stage using a portion of the excess refrigerant from the accumulator.

A controller for a refrigeration system includes a processing circuit having one or more processors and memory. The processing circuit is configured to calculate a superheat of a gas refrigerant exiting a first side of a subcooler based on a measured temperature and a measured pressure of the gas refrigerant and compare the calculated superheat to a superheat threshold. In response to a determination that the calculated superheat is less than the superheat threshold, the processing circuit closes an expansion valve to restrict a flow of the gas refrigerant through a second side of the subcooler. In response to a determination that the calculated superheat is equal to or greater than the superheat threshold, the processing circuit operates the expansion valve to drive a temperature of a subcooled liquid refrigerant exiting the second side of the subcooler to a subcooled liquid temperature setpoint.

The refrigeration cycle apparatus (1) includes a refrigerant circuit (2) that includes a flow channel (29a) through which a refrigerant in a liquid single-phase state flows, and a filter member (35) that is provided in the flow channel (29a) and that captures acid contained in the refrigerant, which passes through the flow channel.

A refrigerant circuit includes a first compressor, a second compressor, a heat-source-side heat exchanger, an expansion mechanism, and a use-side heat exchanger. The refrigerant circuit is capable of performing a single-stage compression operation in which one of the first compressor and the second compressor is driven and the other is stopped, and a two-stage compression operation in which both the first compressor and the second compressor are driven. The control unit controls the refrigerant circuit so that, of the single-stage compression operation and the two-stage compression operation, an operation with a higher compression efficiency is performed.

A controller for a refrigeration system includes a processing circuit having one or more processors and memory. The processing circuit is configured to calculate a superheat of a gas refrigerant exiting a first side of a subcooler based on a measured temperature and a measured pressure of the gas refrigerant and compare the calculated superheat to a superheat threshold. In response to a determination that the calculated superheat is less than the superheat threshold, the processing circuit closes an expansion valve to restrict a flow of the gas refrigerant through a second side of the subcooler. In response to a determination that the calculated superheat is equal to or greater than the superheat threshold, the processing circuit operates the expansion valve to drive a temperature of a subcooled liquid refrigerant exiting the second side of the subcooler to a subcooled liquid temperature setpoint.

A rotary compressor system includes a compressor housing that includes a compressor motor that draws in fluid from a suction side. The fluid is compressed within a compression chamber and discharged through a discharge side. The compression chamber is disposed between the suction side and the discharge side. An overload-protection switch is electrically coupled in series with the compressor motor and is adapted to cut power to the compressor motor responsive to an overload event. A solenoid valve is fluidly coupled between the compression chamber and a location upstream of the suction side and is electrically coupled in series with the overload-protection switch. An interruption of electrical current to the compressor motor also interrupts electrical current to the solenoid valve, which opens the solenoid valve to equalize pressure between the suction side and the discharge side.

A refrigeration unit includes an evaporator circulating a flow of refrigerant therethrough to cool a flow of compartment air flowing over the evaporator, a compressor in fluid communication with the evaporator to compress the flow of refrigerant, an engine operably connected to the compressor to drive operation of the compressor, an expansion device in fluid communication with the flow of refrigerant, and a controller operably connected to at least the engine and the expansion device. The controller is configured to determine an available power to drive the compressor, determine a compressor discharge pressure upper limit based on the available power, compare the compressor discharge pressure upper limit to a requested compressor discharge pressure, and initiate adjustment of the expansion device such that an actual compressor discharge pressure is the lesser of the requested compressor discharge pressure or the compressor discharge pressure upper limit.

A controller for a refrigeration system includes a processing circuit having one or more processors and memory. The processing circuit is configured to calculate a superheat of a gas refrigerant exiting a first side of a subcooler based on a measured temperature and a measured pressure of the gas refrigerant and compare the calculated superheat to a superheat threshold. In response to a determination that the calculated superheat is less than the superheat threshold, the processing circuit closes an expansion valve to restrict a flow of the gas refrigerant through a second side of the subcooler. In response to a determination that the calculated superheat is equal to or greater than the superheat threshold, the processing circuit operates the expansion valve to drive a temperature of a subcooled liquid refrigerant exiting the second side of the subcooler to a subcooled liquid temperature setpoint.