A refrigeration cycle apparatus includes; a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, a first expansion device, a second expansion device, and a load-side heat exchanger are sequentially connected by refrigerant pipes and in which refrigerant is circulated; a controller that controls the refrigerant circuit; a bypass pipe extending from a liquid pipe between the first expansion device and the second expansion device toward a suction side of the compressor; a third expansion device provided at the bypass pipe to decompress the refrigerant that flows through the bypass pipe; and a refrigerant cooler provided at the bypass pipe and downstream of the third expansion device to cause heat exchange to be performed between the refrigerant decompressed by the third expansion device and heat generated from the controller.

This disclosure relates to cold-chain transportation, and more particularly to a refrigerated container refrigeration system capable of preventing freezing of container door, including compressors, oil separators, gas coolers, regenerators, electronic expansion valves, gas-liquid separators, an evaporator, suction pressure regulating valves, oil-level solenoid valves, gas cooler pressure regulating valves, differential pressure regulating valves, an evaporation pressure regulating valve, solenoid valves, check valves, flow meters, pressure sensors, temperature sensors, a door anti-freezing area, a refrigerated container shell, refrigerated container doors, a refrigeration unit, an anti-freezing pipeline and fastening components. Carbon dioxide is selected as refrigerant. A flow two-stage cycle compression refrigeration system with switchable operation pipeline is adopted, and the outlet pipeline of a high-pressure compressor is extended for preventing freezing of container door.

A heat pump system with a refrigerant flow path comprising, in the heating mode of operation: a compressor coupled to receive refrigerant from a heating mode first refrigerant stream and a heating mode second refrigerant stream of the refrigerant flow path; the condenser coupled to receive refrigerant from the compressor; and a heat exchanger for transferring heat between the heating mode first refrigerant stream and the heating mode second refrigerant stream, wherein the heating mode first refrigerant stream comprises: the first expansion valve coupled to receive refrigerant from the condenser; the first evaporator coupled to receive refrigerant from the first expansion valve; and the heat exchanger coupling the heating mode first refrigerant stream from the first evaporator to the compressor, wherein the heating mode second refrigerant stream comprises: the second expansion valve; the heat exchanger coupling the heating mode second refrigerant stream from the condenser to the second expansion valve; and the second evaporator being coupled to communicate refrigerant from the second expansion valve to the compressor, wherein the first evaporator is in a first air flow conduit with a first air inlet for receiving a first air flow, and the second evaporator is in a second air flow conduit coupled to receive the first air flow.

A refrigeration cycle apparatus includes a refrigeration cycle circuit that has a compressor, a condenser, an expansion device, and an evaporator that are connected through a pipe, the refrigeration cycle circuit being configured to allow refrigerant to circulate in the refrigeration cycle circuit, and a controller configured to determine whether the refrigerant leaks or whether the expansion device malfunctions on the basis of a degree of subcooling at an outlet of the condenser and a degree of superheat at an outlet of the evaporator or a degree of superheat at a suction port of the compressor.

An air-conditioning management system includes: an air conditioning apparatus configured to carry out a refrigerant recovery operation of recovering a refrigerant from a refrigerant circuit that connects an outdoor unit and an indoor unit and sending the recovered refrigerant to each recovery unit of the outdoor unit; and a control unit configured to make a determination whether all the recovered refrigerant is sendable to each recovery unit before a start of the refrigerant recovery operation by the air conditioning apparatus, and to output, when determining that all the recovered refrigerant is not sendable to each recovery unit, a command for notifying the determination.

An outdoor unit 3 of an air conditioner 1 includes an outdoor control unit 31 having a first control mode and a second control mode different from each other as control modes of a refrigerant recovery operation for recovering a refrigerant of a refrigerant circuit 9. A flow rate of the refrigerant in the refrigerant circuit 9 in the first control mode is larger than a flow rate of the refrigerant in the refrigerant circuit 9 in the second control mode.

A refrigeration cycle apparatus (1) is capable of performing a refrigeration cycle using a small-GWP refrigerant. The refrigeration cycle apparatus (1) includes a refrigerant circuit (10) and a refrigerant enclosed in the refrigerant circuit (10). The refrigerant circuit includes a compressor (21), a condenser (23), a decompressing section (24), and an evaporator (31). The refrigerant contains is a small-GWP refrigerant.

A method of detecting electrical failure in a refrigeration system is provided. The method includes determining whether a present superheat of the refrigeration system is between a maximum superheat and a minimum superheat for the refrigeration system, the maximum superheat and the minimum superheat defining a normal operating range. The method also includes detecting an electrical property of an expansion valve assembly of the refrigeration system responsive to the superheat being outside the normal operating range. The method further includes determining whether the expansion valve assembly as experienced an electrical failure based on at least the electrical property. A signal indicating that the expansion valve has experienced an electrical failure is generated based on a determination that the expansion valve assembly has experienced the electrical failure.

A control method for an air conditioner comprising a compressor and an outdoor unit, wherein the control method includes: obtaining a suction temperature of the outdoor unit; and selectively adjusting the frequency of the compressor according to the suction temperature of the outdoor unit.

A vehicle air-conditioning apparatus is provided which is capable of expanding an effective range of a dehumidifying and heating mode to achieve comfortable vehicle interior air conditioning. A control device (controller) executes a dehumidifying and heating mode to let a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, let a part of the refrigerant flow from a bypass circuit (refrigerant pipe 13F) to an indoor expansion valve 8, and let the residual refrigerant flow through an outdoor expansion valve 6. In the dehumidifying and heating mode, the control device has a state of controlling the operation of the compressor 2, based on a heat absorber temperature Te and executes a radiator temperature priority mode which enlarges a capability of the compressor when heat radiation in the radiator is insufficient.