Performance enhancement in coal-fired thermal power plants. Part III: Auxiliary power

Auxiliary power in coal-tired power stations accounts for 7% (500 MW units) to 12% (30 MW units) of the gross generated power at the full plant load. The minimum AP varies between 4.5 and 9.0% for the same capacity range. The excessive power due to factors such as coal quality, excessive steam how, internal leakage/ingress in equipment, inefficient drives, distribution net work losses, reduced power quality, ageing, etc., is quantified. An experim ental study has shown that 85.7% of the AP in excess of the design value ca n be traced to coal quality and its indirect effects. The AP can be minimized even below the design value by operational optimiza tion, overhaul of equipment and revamping. The paper discusses in detail th e techniques for restoration of the AP to the designed value and further im provements. Copyright (C) 1999 John Wiley & Sons, Ltd.