According to one embodiment, a refrigeration cycle apparatus includes a motor which including a plurality of phase windings in a mutually unconnected state, a first inverter which controls application of electric power to one ends of the phase windings, a second inverter which controls application of electric power to the other ends of the phase windings, switches connected between the other ends of the phase windings, and a motor controller which selectively sets one of an open-windings mode and a star-connection mode. The motor controller sets, at the time of startup of the motor, the open-windings mode.

A refrigeration system includes a compressor, a condenser, a heat transfer component, and a refrigerant loop arranged to allow a flow of a refrigerant fluid. The compressor, the condenser, and the heat transfer component are connected in the refrigerant loop. The system further includes a bypass path extending between an output side of the compressor in the refrigerant loop and an input side of the heat transfer component in the refrigerant loop. A bypass valve is connected in the bypass path. A control circuit is in communication with the bypass valve. The control circuit is configured to open the bypass valve to allow the refrigerant fluid to pass to the heat transfer component thereby increasing the refrigerant fluid provided to the heat transfer component and artificially increasing a load on the refrigeration system. Other examples refrigeration system and examples methods are also disclosed.

A refrigeration system includes a compressor, a condenser, a heat transfer component, and a refrigerant loop arranged to allow a flow of a refrigerant fluid. The compressor, the condenser, and the heat transfer component are connected in the refrigerant loop. The system further includes a bypass path extending between an output side of the compressor in the refrigerant loop and an input side of the heat transfer component in the refrigerant loop. A bypass valve is connected in the bypass path. A control circuit is in communication with the bypass valve. The control circuit is configured to open the bypass valve to allow the refrigerant fluid to pass to the heat transfer component thereby increasing the refrigerant fluid provided to the heat transfer component and artificially increasing a load on the refrigeration system. Other examples refrigeration system and examples methods are also disclosed.

A fluid temperature control system cools a fluid by means of a multiple refrigeration apparatus including a high-temperature-side refrigerator (100), a medium-temperature-side refrigerator (200) and a low-temperature-side refrigerator (300). The medium-temperature-side refrigerator (200) in the multiple refrigeration apparatus has a medium-temperature-side first evaporator (204) and a medium-temperature-side second evaporator (224). A high-temperature-side evaporator (104) of the high-temperature-side refrigerator (100) and a medium-temperature-side condenser (202) of the medium-temperature-side refrigerator (200) constitute a first cascade condenser (CC1). The medium-temperature-side second evaporator (224) of the medium-temperature-side refrigerator (200) and a low-temperature-side condenser (302) of the low-temperature-side refrigerator (300) constitute a second cascade condenser (CC2). The medium-temperature-side refrigerant and the low-temperature-side refrigerant are the same refrigerant. The fluid allowed to flow by a fluid flow apparatus is cooled by the medium-temperature-side first evaporator (204) of the medium-temperature-side refrigerator (200), and is then cooled by the low-temperature-side evaporator (304) of the low-temperature-side refrigerator (300).

A fluid temperature control system cools a fluid by means of a multiple refrigeration apparatus including a high-temperature-side refrigerator (100), a medium-temperature-side refrigerator (200) and a low-temperature-side refrigerator (300). The medium-temperature-side refrigerator (200) in the multiple refrigeration apparatus has a medium-temperature-side first evaporator (204) and a medium-temperature-side second evaporator (224). A high-temperature-side evaporator (104) of the high-temperature-side refrigerator (100) and a medium-temperature-side condenser (202) of the medium-temperature-side refrigerator (200) constitute a first cascade condenser (CC1). The medium-temperature-side second evaporator (224) of the medium-temperature-side refrigerator (200) and a low-temperature-side condenser (302) of the low-temperature-side refrigerator (300) constitute a second cascade condenser (CC2). The medium-temperature-side refrigerant and the low-temperature-side refrigerant are the same refrigerant. The fluid allowed to flow by a fluid flow apparatus is cooled by the medium-temperature-side first evaporator (204) of the medium-temperature-side refrigerator (200), and is then cooled by the low-temperature-side evaporator (304) of the low-temperature-side refrigerator (300).

Technologies are provided for preventing a working fluid leak from pooling and thus diluting any leaked working fluid from air within a condenser and/or evaporator compartment of the CCU. This can include a computer-readable medium that stores executable instructions that, upon execution, prevent a working fluid leak from pooling within a climate-control unit (CCU) of a transport climate control system. This also includes detecting fulfillment of activation threshold conditions in connection with the CCU. Also, this includes activating a fan in at least one of a condenser unit and an evaporator unit included in the CCU to dilute leaked working fluid from air within the CCU. Further, this includes detecting fulfillment of de-activation threshold conditions and de-activation of an activated fan.

A cryocooler includes an expander that includes a cooling stage, an exhaust temperature sensor that measures an exhaust temperature which is a temperature of a working gas exhausted from the expander and outputs an exhaust temperature signal indicating the measured exhaust temperature, and a controller that compares, during execution of initial cooling in which the cooling stage is cooled from an initial temperature to a cryogenic temperature, the measured exhaust temperature to a reference temperature based on the exhaust temperature signal and completes the initial cooling in a case where a temperature difference between the measured exhaust temperature and the reference temperature is within a reference range.

A cryocooler includes an expander that includes a cooling stage, an exhaust temperature sensor that measures an exhaust temperature which is a temperature of a working gas exhausted from the expander and outputs an exhaust temperature signal indicating the measured exhaust temperature, and a controller that compares, during execution of initial cooling in which the cooling stage is cooled from an initial temperature to a cryogenic temperature, the measured exhaust temperature to a reference temperature based on the exhaust temperature signal and completes the initial cooling in a case where a temperature difference between the measured exhaust temperature and the reference temperature is within a reference range.

Provided are a control method and apparatus for increasing the amount of a circulating refrigerant, and an air conditioner. The control method includes: when a refrigerating capacity need is equivalent to a heating capacity need in the operation of an air-conditioning system, determining whether the discharge temperature of a compressor is greater than a preset safety alert value; if the discharge temperature of the compressor is greater than the safety alert value, adjusting the frequency of a fan of an outdoor heat exchanger; and when the discharge temperature of the compressor is not greater than the safety alert value, controlling to stop the adjustment of the frequency of the fan, and maintaining the air-conditioning system to operate at the adjusted current frequency of the fan.

Provided are a control method and apparatus for increasing the amount of a circulating refrigerant, and an air conditioner. The control method includes: when a refrigerating capacity need is equivalent to a heating capacity need in the operation of an air-conditioning system, determining whether the discharge temperature of a compressor is greater than a preset safety alert value; if the discharge temperature of the compressor is greater than the safety alert value, adjusting the frequency of a fan of an outdoor heat exchanger; and when the discharge temperature of the compressor is not greater than the safety alert value, controlling to stop the adjustment of the frequency of the fan, and maintaining the air-conditioning system to operate at the adjusted current frequency of the fan.