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

Standard Technical Features of BTG System for Supercritical 660/800 MW Thermal Unitsiv) Space Provision6.5.8 Air pre-heatersSpace provision shall be kept on gas inlet side for installation of atleast20% additional economizer surfaces, if required, in future. Structure/hanger design shall be suitable for loads due to these additional surfaces(filled with water) also.i) Design requirements of the air pre-heaters shall be as below:a) Type Regenerative type tri-sector air preheaters with facility of steam coilheating on secondary air side to guardagainst low cold end temperature.orRegenerative type bi-sector air preheaters for primary air and secondaryair with facility of steam coil heatingboth on primary air side and secondaryair side to guard against low cold endtemperature.b) No. of air preheaters persteam generatorTwo tri-sector type APHortwo bi-sector type APH each forprimary air and secondary air.c) Design ambient air 27 o C and 60% RH.d) Boiler load to be 1. 60% BMCR with design/ best/ worstcoal and maximum moisturewhichever gives maximum flowwith one set of APH in service.2. 100% BMCR with design/ best/worst coal and maximum moisturewhichever gives maximum flowwith both sets of APH in service.e) Air temperature rise acrossair preheaterf) Minimum average coldend metal temperature at100% BMCR (withSCAPHs out of service)g) Minimum AH flue gas exittemperature (corrected) at100% TMCR with rangeof specified coalAdequate to achieve the requiredcoal/air mixture temperature at burnerinlet at all loads and for complete rangeof specified coals.76 0 C125 0 C45