LAST STAGE ROTOR BLADES FOR HALF-SPEED NUCLEAR STEAM TURBINE, CORRESPONDING CIRCUMFERENTIAL ROW OF SUCH BLADES, THEIR USE, AND PROCESS OF MANUFACTURING

摘要

A last stage blade (10) for a half speed nuclear steam turbine operating at 50Hz or 60Hz is provided. The blade (10) includes a single piece steel blade body (12) comprising an airfoil (13) having a height (h) extending between a tip (16) and a base (14) between 1850 mm to 2000 mm, and a base diameter (D) between 2900 mm to 3050 mm. Further, the airfoil (13) having an airfoil mass (M) for the defined airfoil height (H), wherein the airfoil mass (M) to height (H) ratio is in a range of 70 kg/m to 80 kg/m, enabling substantially smaller centrifugal pull on a rotor. The blade (10) further includes a blade root (18), extending from the base, configured to be attachable mounted in a rotor groove of the rotor. Such configuration is capable of withstanding 1.5 times a rotational speed of the turbine for half speed turbine. Corresponding circumferential row of last stage blades, use of such a circumferential row of last stage blades in a half speed nuclear steam turbine, and method of manufacturing a last stage blade are also provided.