Optical probe for measurement of steam wetness fraction in lp turbines

摘要

A traversing probe for measurement of steam wetness fraction has been developed and field tested by EPRI. When used in the wet stages of condensing steam turbines, the probe system provides the wetness fraction and pressure data required to define the enthalpy of the steam. The traversing probe enables measurement of state point efficiency of the low pressure section, or of individual stages in the low pressure turbine. It can be used to quantify the increase in used energy resulting from turbine steampath upgrades. Spanwise distributions of steam properties at the turbine exit and interstage traverse locations provide details on the blading performance that are valuable in the design process.