ELECTRO-PNEUMATIC ROTATIONAL SPEED CONTROL METHOD OF STEAM TURBINE FOR DRIVING SUCH AS COMPRESSOR OR BLOWER

摘要

PURPOSE:To keep the rotational speed of a turbine constant if load fluctuates, by detecting the fluctuation of the rotational speed of the turbine, which is caused by an outer disturbance, and regulating the quantity of steam which flows into the turbine, according to the quantity of the detected fluctuation and by means of a pneumatically driven regulating valve. CONSTITUTION:On the rotary shaft of a steam turbine T which drives such as a compressor, a rotational speed detecting unit 1 is set, a pulse signal detected by an electromagnetic pickup 2 is converted into a signal for a digital tachometer by a converter 3, and at the same time, it is converted into direct current and input into an indicating regulator 4. An output signal is produced according to the input signal, by the regulator 4, an air pressure signal is sent to a valve positioner 6 through an electro-pneumatic converter 5, a regulating valve 8 is opened/closed by an air cylinder 7, and consequently, the rotational speed of the turbine can be kept constant, even if load fluctuates.