Standard Technical Features of BTG System for Supercritical 660 ...
Standard Technical Features of BTG System for Supercritical 660 ...
Standard Technical Features of BTG System for Supercritical 660 ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
<strong>Standard</strong> <strong>Technical</strong> <strong>Features</strong> <strong>of</strong> <strong>BTG</strong> <strong>System</strong> <strong>for</strong> <strong>Supercritical</strong> <strong>660</strong>/800 MW Thermal Unitsh) Minimum flue gas exittemperature (<strong>for</strong> completerange <strong>of</strong> specified fuels)i) Air leakage (at 100%TMCR load <strong>for</strong> completerange <strong>of</strong> coals)5 0 C above acid dew point <strong>of</strong> flue gas.10% <strong>of</strong> the flue gas weight entering airheater.ii)iii)For meeting the requirement <strong>of</strong> rated coal/ air mixture temperatures atburner inlet at part load operations <strong>of</strong> steam generator with coals <strong>of</strong>excessive moisture and under conditions <strong>of</strong> low ambient temperatures,economizer bypass duct may be provided along with necessary dampers,expansion joints, structures etc. Even in case economizer bypass isprovided, the sizing <strong>of</strong> air preheaters shall ensure that the rated milloutlet temperatures are achieved, <strong>for</strong> complete range <strong>of</strong> specified coals,with economizer bypass fully closed.APH inlet/ outlet flue gas/ air ducts shall have aerodynamic design <strong>for</strong>even distribution <strong>of</strong> air/ flue gas at all loads.iv) The air pre heaters shall be <strong>of</strong> rotary regenerative, Lungstorm orapproved equivalent type with axis <strong>of</strong> rotation as vertical. Theconstruction <strong>of</strong> air pre heaters shall con<strong>for</strong>m to the following:a) Heating Elements1. Cold end : Corten steel, minimum 1.2 mm thick2. Hot/intermediate end : Carbon steel, minimum 0.8 mm thickb) Bearings (<strong>for</strong>ced lubricated and oil cooled)1. Cold end : Spherical roller thrust bearing2. Hot end : Radial guide bearingNote: Only metallic hoses shall be used <strong>for</strong> bearing cooling/lubrication. Rubber hoses shall not be acceptable.c) Air heater seals 1. Externally (manually/ automatically) adjustableand easily replaceable type.2. The maximum air-in-leakage to flue gas after3000 hours continuous operation <strong>of</strong> the SteamGenerator with coal shall be guaranteed anddemonstrated. It shall also be demonstrated thatthe drift in air heater leakage (percentagechange in air-in-leakage) does not exceed 1%,one year after demonstration <strong>of</strong> aboveguaranteed air-in-leakage.3. Seals shall have life <strong>of</strong> not less than 2 years(with leakages not exceeding guaranteedlimits).46
Change language