11 April 2012


Supercritical Boiler
 1.        Operating Pressure >  225 Kg/Cm2,  It Is Called A Supercritical Boiler.
2.           The Most Techno-Economical Parameters For Supercritical Plants Envisaged Are:
 Main steam Pressure
@ SH outlet  is 250 Kg/Cm
540 Deg.C
Main Steam Temperature At Sh O/L.
566 Deg.C
Hrh Temperature At Rh O/L.
3.          Improvement In Cycle Efficiency for above Parameters Is Of The Order Of 3%.
4.       There Are Two Types Of Water Walls  Arrangements In The Case Of  Once Through Boiler:
A)             Spiral Wound WW.
B)              Vertical Ribbed WW.
5.               Most Of The Once Through Boilers In The World Are With Spiral Wound WW.  This Arrangement Has The Advantage Of Equal Heat Absorption By All The Steam Generating Tubes.
     The Disadvantage Of This Arrangement Is That The Tubes Are Not Self-Supporting.  Hence, Extra Supports Are Provided To WW For This Arrangement.
  Typical Materials Used For Super critical Boiler

Elements Of Boiler

Carbon Steel
Water Wall
Low Alloy Ferritic Steel
Pressure Vessels
(Separator, Drain Tank)
Low Alloy Ferritic Steel
Sh Tubes (Heating Area)
Austenitic Steel
(Tp347h / Tp321h)
Sh Tubes (Non-Heating Area)
Medium Alloy Steel
Main Steam Pipe
Medium Alloy Steel
HRH Pipe
Medium Alloy Steel