Start-up curve for HRSG 2

[barbe]

Hallo,

I dont know , how fast I can be with my boiler (HRSG behind gas turbine) on desired parameters from cold start. How fast I can change a temperature of boiler drum, and how fast I can change a pressure ........
I know something about trend with 3°C / minute . But Im curious how look a material properties, how look this process in reality , what are experience with boiler starting .....

Thank you for everything what you can help me.

Best Regards
jaro kuruc

 

[davefitz]

The limitations to starting up a HRSG are asociated with the folowing:
a) thermal stress in HP steam drum

b) thermal stress in HP main steam outlet header

c)temperature differnence between tube stubs and outlet header on HP superheater and reheater outelt headers, if a partial penetration weld was used.

d) transient end ractions and bending moments associated with temperature diferentials during unusual thermal-hydraulic events. Some examples are temporary lack of downcomer circulation ( due to hi pressure driop in the drum sepearators causing a natural circulationloop to form within the first several rows of evaporator whiel the last severla rows are stagnant), Ledineg static flow instability in the LP economizer/preheater.

The limits of items a and b are defined in the german boiler code TRD 301 annex 1 or EN 12952-3:2001 annex B

Other limits not associated with the HRSG are the time to preheat the HP main steam line and turibne inlet valve and HP casing.