Standard Technical Features of BTG System for Supercritical 660 ...

Standard Technical Features of BTG System for Supercritical 660/800 MW Thermal UnitsCHAPTER - 2OPERATING CAPABILITY OF PLANT2.1 The plant shall be designed to operate as a base load station and shall have adesign life of minimum twenty five (25) years. However, continuous operationunder two shift and cyclic modes during certain periods is also envisaged. Thedesign of the plant equipment and control system would permit participationof the plant in automatic load frequency control. The major operatingcapabilities for the unit(s)/ plant are envisaged as under:2.1.1 Operate continuously with turbine under VWO condition with rated steamparameters, specified rated condenser pressure and 1% cycle make up.2.1.2 Sliding pressure/ modified sliding pressure operation from rated load down to40% of rated load. The modified sliding pressure operation shall comprise ofconstant pressure operation from rated load to approximately 90% of ratedload and then sliding pressure operation down to 40% of rated load. At anyoperating load upto 100% rated load, the turbine shall be capable to achieve aninstantaneous increase in turbine output by 5% of the corresponding load, byopening turbine control valves/ overload valves wide open.2.1.3 The plant shall have adequate provision for quick start-up and loading of theunits to full load at a fast rate.2.1.4 Operate continuously with all HP heaters out of service with maximumspecified cooling water temperature, 1% cycle make up and normal auxiliarysteam requirement being tapped from cold reheat line, to generate maximumoutput without over stressing turbine components. The power output of theunit under this operating condition shall not be less than the rated output (660or 800 MW, as applicable).2.1.5 In case of sudden reduction in demand (load throw off), the unit should getsafely unloaded and stabilized for operation at house load with HP- LP bypassopen to required capacity.2.1.6 Operate continuously at rated output (660 or 800 MW, as applicable) underrated steam conditions, specified worst condenser pressure, 1% cycle make-upand 47.5 Hz grid frequency.2.1.7 The design of the plant equipment and control system would permitparticipation of the plant in automatic load frequency control.2.2 Steam generator, turbine generator and auxiliaries shall be designed to cater tothe above operating conditions with adequate margin as per standard practiceprevailing in the fossil fired power plants.6