Scroll compressor and refrigeration cycle apparatus

A scroll compressor comprising:

• a shell;
• a fixed scroll and an orbiting scroll disposed in the shell;
• scroll wraps provided respectively in the fixed scroll and the orbiting scroll, the scroll wraps being engaged with each other to form a plurality of compression chambers;
• a crankshaft configured to cause the orbiting scroll to perform eccentric revolving motion;
• a tip seal member inserted in a tip of each of the scroll wraps of the orbiting scroll along a spiral direction and being in sliding contact with a baseplate of the fixed scroll;
• and
• injection ports provided through the baseplate of the fixed scroll and configured to introduce refrigerant having an intermediate pressure between suction pressure and discharge pressure into the compression chambers from an outside of the shell, wherein
• the refrigerant is composed only of carbon dioxide or is a mixed refrigerant containing carbon dioxide, and
• each of the injection ports has a diameter ϕinj and the tip seal member has a width TIP in a direction perpendicular to the spiral direction, the diameter ϕinj and the width TIP having a relationship of ϕinj≤0.95×TIP.