HRSG Stack Temperature
HRSG Stack Temperature
(OP)
We currently operate 4 ABB HRSGs in combined cycle orientation. On one of the four HRSGs the stack temperature is around 60 degrees higher than the average of the other three. What would be some of the causes for this? What should I look into in getting the heat transfer across the boiler tubes back? Any ideas? If it is indeed true that I al loosing thermal effiecency in this particular HRSG how can I determine if it is real? Would steam flows be less in this HRSG as compared to the others?





RE: HRSG Stack Temperature
RE: HRSG Stack Temperature
a) the LP economizer recirc pump may be
b) the LP economizer bypass valve is open
c) excessive buildup of ammonium bisulphate- due to firing high sulphur fuel with excessive ammonia slip past the scr- time for a washing
d) LP drum pegging steam was left open- check pressure of LP drums for the 3 units
e)other possiblities depending on how the total plant is integrated together
f) LP steam block valve to stg is closed
g) gas thermocouples in error.
RE: HRSG Stack Temperature
RE: HRSG Stack Temperature
There are sooooooo many variables that could cause that it would be impossible to reasonbly determine the cause without a whole lot more information from you.
rmw