Patent ID: 6853945
Filing Date: 2005-02-08
Classification: F01D,F05D

Abstract:
1. A method of monitoring radial clearances in a steam turbine during operation of the turbine, the turbine comprising an outer shell and a rotor, the rotor comprising a rotor shaft and a plurality of rotor blades attached to the rotor shaft, said method comprising: measuring a temperature of the rotor shaft at a time measuring a temperature of at least one of the plurality of rotor blades at time measuring a temperature of the shell at time calculating a shaft radial growth between time calculating a blade growth between time calculating a shell radial growth between time determining a change in a radial gap between the shell and a distal end of the rotor blade from time where the growth calculations are performed by using a finite difference method to obtain the instantaneous volume averaged temperatures of the rotor and the shell, and wherein at least one of the surrounding gas temperature and the measured blade temperatures is used to approximate the instantaneous averaged temperature of the plurality of rotor blades.