Refrigerant cycle system

A refrigerant cycle system comprising:

• a compressor for compressing refrigerant;
• a first heat-exchanging portion for cooling and condensing gas refrigerant discharged from the compressor by radiating heat;
• a gas-liquid separator for separating refrigerant into gas refrigerant and liquid refrigerant, into which all of refrigerant after passing through the first heat-exchanging portion is introduced;
• a second heat-exchanging portion disposed downstream of the first heat-exchanging portion, for cooling and condensing refrigerant flowing from the gas-liquid separator by radiating heat;
• a gas-refrigerant return passage through which gas refrigerant in the gas-liquid separator is introduced into the second heat-exchanging portion;
• a decompression device disposed downstream of the second heat-exchanging portion, for decompressing refrigerant after passing through the second heat-exchanging portion;
• an evaporator disposed downstream of the decompression device, for evaporating refrigerant flowing out of the decompression device;
• and
• a heating unit for adjusting a heating amount of the liquid refrigerant in the gas-liquid separator in accordance with any one of a super-heating degree of gas refrigerant discharged from the compressor and a super-heating degree of gas refrigerant at an outlet of the evaporator.