help needed about steam turbine 1

[bilalamd]

Greetings!

I am working at a 1223 MW CCPP installed with 2 x GE H class gas turbines and 1 x Alstom triple pressure steam turbine. We are having a shutdown these days and got a chance to go inside the condenser or LP turbine exhaust section. There, we saw an open flange at either side of the LP turbine after its final stage and before de-superheating nozzles manifold. That open flange is associated to a line that is going vertically in the upward direction but it cant be traced because of space issue.

I have checked the cross sectional diagram of the steam turbine and according to my knowledge both of the above mentioned flanges are shown there ( attached please find the drawing) .

Can anyone please help me and my follows in understanding the purpose of these two lines ending on open flanges? any help in this regard will be very beneficial

link to the diagram (

https://files.engineering.com/getfi...7e70-49cd-8d79-cd52bd62a6a4&file=Capture1.PNG

)

thanks in advance

 

[stgrme]

The flanges, shown in the cross-sectional diagram, are for moisture removal from upstream of the last LP stage. I have enclosed a PDF file with the holes highlighted in yellow to show the connection of the chamber above each flange to the chamber above the last stage stationary blades at each end of the LP turbine.

Each moisture drain is usually routed to the condenser through a plug-resistant orifice. The orifice limits the amount of steam carried into the condenser with the moisture.

In your turbine, the flanges are open directly to the vacuum space of the condenser. I suggest that you contact GE (now responsible for Alstom designs) to determine if an orifice is required for each drain, and if required, the appropriate size of the orifice.

Best of luck!