Refrigeration cycle device

A refrigeration cycle device comprising:

• a refrigerant circuit including a first compressor, a second compressor, a heat-source-side heat exchanger, an expansion mechanism, and a use-side heat exchanger, and capable of performing a single-stage compression operation in which one of the first compressor and the second compressor is driven and an other is stopped, and a two-stage compression operation in which both the first compressor and the second compressor are driven;
• and
• a controller configured to control 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, wherein
• in a first operation in which a required capacity of the refrigerant circuit is below a predetermined capacity threshold, the controller is configured to control the refrigerant circuit so that the single-stage compression operation is performed,
• in a second operation in which the required capacity of the refrigerant circuit is not below the predetermined capacity threshold, the controller is configured to control the refrigerant circuit so that the two-stage compression operation is performed, and
• the predetermined capacity threshold is a value that changes in accordance with a physical quantity indicating a difference between a quantity correlated with a high pressure in the refrigerant circuit and a quantity correlated with a low pressure in the refrigerant circuit.