Refrigerant-containing composition, use thereof, refrigerating method using same, and refrigerator comprising same

A composition comprising a refrigerant, the refrigerant comprising CO2, difluoromethane (R32), pentafluoroethane (R125), 2,3,3,3-tetrafluoro-1-propene (R1234yf), and 1,1,1,2-tetrafluoroethane (R134a),

• wherein when
• the mass % of CO2 based on the sum of CO2, R32, R125, R1234yf, and R134a in the refrigerant is x,
• the mass % of R1234yf based on the sum of R1234yf and R134a is r, and
• the mass % of R32, the mass % of R125, and the mass % of the sum of R1234yf and R134a based on the sum of CO2, R32, R125, R1234yf, and R134a are respectively represented by a, b, and c,
• the refrigerant satisfies the following requirements (1) or (2):
• (1) 4.2>x≥2.8;
• 75≥r≥0;
• and
• coordinates (a, b, c) in a ternary composition diagram whose vertices are a point of (100−x) mass % of R32, a point of (100−x) mass % of R125, and a point of (100−x) mass % of the sum of R1234yf and R134a are within a triangular region surrounded by line segments that connect the following points:
• point A [(0.0086x−0.0748)r+0.5x+55.38, (−0.0126x+0.106)r+0.9357x+23.4, 100−a−b−x],
• point B [(−0.0077x−0.0756)r−3.0143x+65.26, (0.0126x+0.0392)r+(−0.4x+27.08), 100−a−b−x], and
• point C [(−0.0154x−0.042)r−1.4214x+60.8, (0.0171x+0.004)r−2.7857x+33.8, 100−a−b−x], or on the line segments, or
• (2) 5.5%≥x≥4.2%;
• 75≥r≥0;
• and
• coordinates (a, b, c) in a ternary composition diagram whose vertices are a point of (100−x) mass % of R32, a point of (100−x) mass % of R125, and a point of (100−x) mass % of the sum of R1234yf and R134a are within a triangular region surrounded by line segments that connect the following points:
• point A [(0.0083x−0.0737)r+0.4x+55.8, (−0.0092x+0.092)r+0.7692x+24.099, 100−a−b−x],
• point B [(−0.0071x−0.0783)r−2.8692x+64.651, (0.0114x+0.0442)r−0.4077x+27.112, 100−a−b−x], and
• point C [(−0.0132x−0.0512)r+(−1.5615x+61.388), (0.0123x+0.0243)r+(−2.7692x+33.731), 100−a−b−x], or
• on the line segments.