A refrigeration system includes a refrigerated cavity, a first compression system, and a second compression system. The refrigeration system further includes a controller configured to operate the refrigeration system in a first mode in which the first compression system and the second compression system operate to cool the refrigerated cavity. The refrigeration system is further configured to selectively operate the refrigeration system in a second mode in which a refrigerant discharged from the second compressor is routed through the first evaporator to defrost the first evaporator.

A refrigerator comprises: a storage compartment, at least divided into a refrigerating compartment and a freezing compartment a first evaporator, arranged at a cooling compartment connected to the storage compartments through supply air ducts; a second evaporator, arranged inside the freezing compartment a switching valve, used to switch the flow of a refrigerant to a refrigerant channel connected to the second evaporator; a fan, used to enable cooled air in the first evaporator to flow from the cooling compartment to the storage compartments; a first air duct damper, inserted in the supply air duct connected to the refrigerating compartment and a second air duct damper, inserted in the supply air duct connected to the freezing compartment.

Methods and systems are provided for operating a dual loop heat pump system in a de-icing mode which enables the heat pump system to maintain a target rate of heat delivery to a cabin while de-icing an outside heat exchanger by leveraging waste-heat available at one or more waste-heat sources. In one example, responsive to an outside heat exchanger de-icing request and a cabin heating request, selecting a first waste-heat heat exchanger based on a temperature of the first waste-heat heat exchanger exceeding a first temperature threshold, flowing coolant to the first waste-heat heat exchanger, flowing a first portion of the coolant exiting the first waste-heat heat exchanger to a cabin heat exchanger, and flowing a second portion of the coolant exiting the first waste-heat heat exchanger to an outside heat exchanger.

Methods and systems are provided for operating a dual loop heat pump system in a de-icing mode which enables the heat pump system to maintain a target rate of heat delivery to a cabin while de-icing an outside heat exchanger by leveraging waste-heat available at one or more waste-heat sources. In one example, responsive to an outside heat exchanger de-icing request and a cabin heating request, selecting a first waste-heat heat exchanger based on a temperature of the first waste-heat heat exchanger exceeding a first temperature threshold, flowing coolant to the first waste-heat heat exchanger, flowing a first portion of the coolant exiting the first waste-heat heat exchanger to a cabin heat exchanger, and flowing a second portion of the coolant exiting the first waste-heat heat exchanger to an outside heat exchanger.

An air conditioner includes an outdoor heat exchanger in which N heat exchange units are spaced apart from one another sequentially in a vertical direction N expansion valves respectively connected to the N heat exchange units; N hot gas pipes respectively connected to the N heat exchange units; N hot gas valves respectively installed in the N hot gas pipes; and a controller configured to control the N expansion valves and the N hot gas valves to defrost the N heat exchange units, wherein the controller is configured to defrost a bottom heat exchange unit first, then defrost a top heat exchange unit, and defrost the heat exchange units located under the top heat exchange unit sequentially from a second highest heat exchange unit to the bottom heat exchange unit after defrosting the top heat exchange unit.

The refrigeration cycle apparatus includes a refrigerant circuit, a controller to control the refrigerant circuit, a bypass flow path, and a flow control valve. The bypass flow path communicates between the discharge side of the compressor and the first outdoor heat exchanger or between the discharge side of the compressor and the second outdoor heat exchanger. The flow control valve is provided to the bypass flow path. The refrigerant circuit is configured to be able to perform a heating defrosting simultaneous operation. The heating defrosting simultaneous operation is an operation of supplying part of the refrigerant discharged from the compressor to one of the first outdoor heat exchanger and the second outdoor heat exchanger via the bypass flow path, causing the other of the first outdoor heat exchanger and the second outdoor heat exchanger to serve as an evaporator, and causing the indoor heat exchanger to serve as a condenser.

A cross-connected refrigeration system includes a first refrigeration subsystem and a second refrigeration subsystem that are fluidly coupled by a header, each of the first refrigeration subsystem and the second refrigeration subsystem including a refrigeration loop including a compressor, a condenser, an expansion device, and an evaporator, and a heating loop including an electrically-controlled valve, and the evaporator, and a header connection that connects the refrigeration loops and the heating loops of the first refrigeration subsystem and the second refrigeration subsystem to a common header, respectively. The compressor in the first refrigeration subsystem is selectively deactivated and the electrically-controlled valve in the first refrigeration subsystem is selectively opened such that compressed gas from the compressor in the second refrigeration subsystem enters the heating loop of the first refrigeration subsystem and heats the evaporator of the first refrigeration subsystem.

When a controller performs a defrosting operation in which frost on an outdoor heat exchanger is caused to be melted, the controller is configured to perform a first defrosting control in which a switching state of a switching device is set to a first state, after the controller performs the first defrosting control, perform a second defrosting control in which the switching state of the switching device is set to a second state, and after the controller performs the second defrosting control, perform a third defrosting control in which the switching state of the switching device is set to the first state.

An air conditioner includes an outdoor heat exchanger in which N heat exchange units are spaced apart from one another sequentially in a vertical direction N expansion valves respectively connected to the N heat exchange units; N hot gas pipes respectively connected to the N heat exchange units; N hot gas valves respectively installed in the N hot gas pipes; and a controller configured to control the N expansion valves and the N hot gas valves to defrost the N heat exchange units, wherein the controller is configured to defrost a bottom heat exchange unit first, then defrost a top heat exchange unit, and defrost the heat exchange units located under the top heat exchange unit sequentially from a second highest heat exchange unit to the bottom heat exchange unit after defrosting the top heat exchange unit.

An apparatus includes a high side heat exchanger, a subcooler heat exchanger, a flash tank, a load, and a compressor. The high side heat exchanger removes heat from a refrigerant. The subcooler heat exchanger receives the refrigerant. The flash tank stores the refrigerant. During a first mode of operation, the load uses the refrigerant to cool a space proximate the load and the compressor compresses the refrigerant. During a second mode of operation, the subcooler heat exchanger receives the refrigerant from the flash tank, transfers heat from the refrigerant from the high side heat exchanger to the refrigerant from the flash tank and directs the refrigerant from the flash tank to the compressor. During the second mode of operation, the compressor compresses the refrigerant from the subcooler heat exchanger and directs the compressed refrigerant to the load to defrost the load.