Cooling method and system for cooling blades of at least one blade row in a rotary flow machine

The invention refers a method and to a cooling system for cooling blades (1) of at least one blade row in a rotary flow machine, comprising an axial flow channel (2) which is radially limited on the inside by a rotor unit (3) and at the outside by at least one stationary component (4), said blades (1) are arranged at the rotary unit (3) and provide a shrouded blade tip facing radially to said stationary component (4) The invention is characterized in that pressurized cooling air (8) is fed through from radially outside towards the tip of each of said blades (1) in the at least one blade row, and said pressurized cooling air (8) enters the blades (1) through at least one opening (9) at the shrouded blades' tip.