Abstract
A new optical torque measurement method was applied to diagnosis of thermal efficiency of advanced combined cycle, i.e. ACC, plants. Since the ACC power plant comprises a steam turbine and a gas turbine and both of them are connected to the same generator, it is difficult to identify which turbine in the plant deteriorates the performance when the plant efficiency is reduced. The sensor measures axial distortion caused by power transmission by use of laser beams, small stainless steel reflectors having bar-code patterns, and a technique of signal processing featuring high frequency. The sensor was applied to the ACC plants of TOKYO ELECTRIC POWER COMPANY in order to analyze each steam turbine performance for selection of the plant that steam was extracted, following the success of inspection of the sensor reliability in ACC.
