Steam Condenser Not Working: Pressure & Temperature Issues

[Nirmsing1411]

The condensate drain from a steam condenser is expected to be about 50 deg C. It's only 38 deg C or so. There's a mix of steam and non condensable gases coming into the condenser. Its pressure seems slightly higher, being about 0.25 bar abs instead of 0.2 bar. What does it indicate? Also, no significant difference in cooling water flow and the inlet outlet temps, compared to other healthy units under similar load conditions.

 

[anorlunda]

You should do a heat balance on this condenser and one of the others and compare the numbers. It sounds wrong that you have these differences but zero difference in the cooling water flow or temperatures.

You don't really give enough information, but it sounds like the flow rate (pounds per second) of moisture and/or steam into that condenser is different than the other condensers. Presumably, they should be the same. Look for differences in the upstream drains between this condenser and the others.

Are these condensers catching exhaust from steam turbines? If so, also check for differences in reheat spray, and for abnormal sealing steam flows.

 

[jim hardy]

The condensate drain from a steam condenser is expected to be about 50 deg C. It's only 38 deg C or so. There's a mix of steam and non condensable gases coming into the condenser. Its pressure seems slightly higher, being about 0.25 bar abs instead of 0.2 bar. What does it indicate? Also, no significant difference in cooling water flow and the inlet outlet temps, compared to other healthy units under similar load conditions.

How's the air ingress on those other units?

In a condenser, steam flowing toward the tubes should reheat the water dripping from them back up to nearly saturation.
Too much air interferes with that.
Our condenser had trays interspersed in the tube bundle to catch the condensate and route it out of the tubes on an inclined plane, providing lots of surface area for heat transfer from incoming steam. That brings condensate back closer to saturation temperature.

image courtesy of these guys
http://www.hts.org.uk/downloads/TroubleshootingSteamSurfaceCondensers.pdf

Cooling water temperature rise shouldn't be much different between your condensers,,, .
Compare :
the enthalpy change between saturated vapor and saturated liquid
to
the enthalpy change between saturated vapor and your twelve degrees subcooled liquid.
Divide one by the other, i wager you get pretty close to 1.That's my guess.

Is the air ejector howling ? What tests can you run ?

@Nirmsing1411 have you gone away ?