GOVERNING OF STEAM TURBINES
GOVERNING OF STEAM TURBINES Requirement of governing system:- Controlling and regulating of a turbine according to variable demand. The regulation of turbine is done by maintaining control of speed, pressure and flow by the help of governors. Governing of turbine maintains the speed of turbine at constant level irrespective of load. Governing of steam turbine is classified according to the mechanism (i) Throttle governing (ii) Nozzle control governing (iii) By-pass governing (iv) Combined governing (i.e., Combination of above as throttle and nozzle control governing or ‘throttle and by-pass governing). (i) Throttle Governing: Throttle governing of steam turbine bases upon the throttling of steam up to suitable pressure and regulate the mass flow of steam through the turbine so as to control the output of turbine. Here in throttle governing, aim is to alter the mass flow rate as for example by reducing it, the available energy gets reduced and hence l