RETROFITTING METHOD OF STEAM TURBINE AND RETROFITTED TURBINE, TO PROVIDE RETROFITTED TURBINE HAVING HIGH EFFICIENCY

摘要

PURPOSE: A retrofitting Method of a steam turbine and an retrofitted Turbine are provided to secure an interface between a substitute steam path of improved pulse stage design and an outside shell of a turbine originally having a steam path of reaction stage design and to prevent thermal stress during excessive operation by maintaining the axial, vertical, and radial positions and keeping the thickness of an inner shell minimum. CONSTITUTION: A retrofitting Method of a steam turbine comprises steps of removing an upper outer shell half part, a first inside shell, and a first rotor from a lower outside shell half part of a first steam turbine; inserting a lower carrier section into the lower outside shell half part; providing a second rotor(30) and a second inside shell partially defining a second steam path of a second diameter smaller than a first diameter of a first steam path; arranging a lower inside shell half part of the second inside shell in the lower carrier section; arranging the second rotor in the lower inside shell half part of the second inside shell; arranging an upper inside shell half part of the second inside shell around the second rotor; arranging an upper carrier section(38) around the upper inside shell half part of the second inside shell; and fixing the upper outside shell half part to a lower outside shell half part of the first turbine to provide an opened second steam turbine having the second steam path with a diameter reduced.