Refrigeration cycle device and control method

A refrigeration cycle device comprising:

• a refrigerant circuit to make a refrigerant flow in a compressor to compress a refrigerant, a condenser, an expansion valve to regulate a flow rate of a refrigerant, an evaporator, and an accumulator to supply a refrigerant to the condenser in this order;
• and
• a control device to control the expansion valve,
• wherein the control device includes:
• a supercooling level controller to calculate a first opening degree of the expansion valve such that a supercooling level of a refrigerant follows a target value and to output a calculation result:
• a discharge temperature controller to calculate a second opening degree of the expansion valve such that temperature of a refrigerant discharged from the compressor follows a predetermined upper limit and to output a calculation result;
• and
• a first maximum selector to output a maximum value out of the output of the supercooling level controller and the output of the discharge temperature controller,
• wherein the control device controls the expansion valve by using the value outputted from the first maximum selector.