STEAM TURBINE STAGE MEASUREMENT SYSTEM AND A METHOD THEREFOR

摘要

The invention relates to the calculation of an absolute and relative axial displacement in a steam turbine (10) between a stationary vane row (18) and a rotating blade row (21) that form a stage of the steam turbine. This is achieved by using a measurement signal of an outer casing absolute axial expansion sensor (22), a measurement signal of an inner to outer casing differential axial expansion sensor (24) and a measurement signal for a rotor to outer casing differential axial expansion sensor (28). A steam turbine stage measurement system and a method for calculating and estimating the absolute and relative axial displacements is provided enabling continuous, real-time measurements for operational optimisation.