Steam Blow into Condenser 1

[akifozmen]

Flushing, chemical cleaning and steam blow are consequent steps to achieve a clean HRSG and piping system in a Combined Cyle Power Plant. Conventional method for steam blow purges the steam produced at the HSRG's. On continous steam blow method, there is an opportunity to divert the steam to condenser following purge to atmosphere at beginning step. Afterwards, installing a filter to upstream of the condenser, the blow steam is directed to condenser. It is said that this method reduces demineralized water consumption considerably.

Please share your thoughts and experiences in terms of pros and cons for steam blow to condenser.

 

[Strong]

Can your startup schedule and budget afford to repair condenser damage, if it occurs?
Walt

 

[akifozmen]

Thank you very much for your kind reply. In fact no. I have heared condenser tube cracks and consequent falures after sometime of operation. Therefore I wished to ask if there are succesful examples of this method.

 

[crshears]

Not that I know how it's done, but I seem to recall that some CANDU nuclear reactor steam cycles involve the use of "condenser steam discharge valves" [ CSDV's ] that permit a degree of steam turbine unloading while allowing the reactor to remain at full power; obviously a loss of efficiency ensues, but the operational benefits of not having to maneuver the reactor power output around as much reduces the likelihood of the reactor "poisoning out" during excursionary events as well as reducing the loss of demineralized water from the steam cycle as compared with ASDV [atmospheric steam discharge valve] equipped cycles. Perhaps someone else can offer more details...?

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[akifozmen]

Thanks crshears, that is valuable info. I will look at that.

 

[byrdj]

many decades past, when I was ask to comment on Steam Blows as the turbine rep, I said I would be glad to, but they needed to know, we sold spare parts!
the little info I have stumbled accross in the last years sitting at home, it sounds like SPE is pretty common (ie poor steam blow cleaning).

 

[macmet]

In my past job I was a field service engineer for a HRSG company who recommended continuous steam blows. We had a large plant where the customer almost elected to do a steam blow into the condenser because of the difficulty and cost of water, but at the last minute they changed their mind and we stuck with our normal steam blow to atmosphere procedure. I would think the process would work assuming your trash blows go to atm like you mentioned, but unfortunately I never actually saw it happen.

I believe the company that did the pre-planning work for the steam blow to condenser was Boyle Energy Services. They ran a few steam blows for us and although they were a lot to deal with, I thought they were quite good.

Cheers,

Macmet

 

[EdStainless]

The real risk is that if you start blowing to the condenser too soon you will have a lot of crap in the condensate and it will all need to be polished before use. And of course the condenser cleaned as well. Better to dump the suspect grade steam and play it safe.

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P.E. Metallurgy, Plymouth Tube