"Condensate" Line Definition

[StevenHPerry]

After a let down valve, a condensate line flashes ~14% by mass to steam.

Is H20 at quality X=0.14 steam or condensate?

After working out the mixture's volume, this condensate line has been sized (by "others") for ~100 ft/s flow.

-SP

 

[SNORGY]

Looks like whoever sized the line considered it to be "steam".

Hydraulically, I would be inclined to treat it as horizontal two-phase flow and use the Baker Chart in combination with Lockhart & Martinelli.

Regards,

SNORGY.

 

[MisterDonut]

By volume, it is mostly steam, so treating it as steam should be conservative. Limit velocity to 50 ft/sec.

 

[racookpe1978]

The "instaneous" conditions stated aren't.

That is, a few seconds before, and a few aeconds after the problem's 14% quality steam and water mix, the line will actually be heating up, or at a continuous temeprature, or be changing again as the control valve changes position.

The only conservative answer is to assume steam conditions for the max flow rate and limit fluid velocity as if there were 100% steam "sometimes" - Because "sometimes' there will be 100% steam flow. (Most of the time? No. It will be mixed flow. But when is your erosion and problems occurring?