US Patent 11274871 Refrigeration apparatus

Provided is a refrigeration apparatus capable of reducing the leakage of a refrigerant even when a refrigerant leak occurs in a defrosting operation of a usage-side heat exchanger. When a refrigerant leak situation around a usage-side heat exchanger satisfies a predetermined leak condition in performing a defrosting operation with a connection state of a four-way switching valve brought into a defrosting connection state in which a heat source-side heat exchanger functions as an evaporator for a refrigerant and a usage-side heat exchanger functions as a radiator for the refrigerant, a controller performs density lowering control to lower a refrigerant density in the usage-side heat exchanger while maintaining the four-way switching valve at the defrosting connection state.