Rick wrote:
The balance is taken for granted, at a given vacuum I can remove a given
amount of heat ... removing a given amount of heat will produce a given
vacuum for a given steam flow, it is very simple, don't put any more in
than you can remove.

Simple in theory, complicated in practice.

... Loss of vacuum equates to a loss of power in a
steam plant, it's like putting a potato in an exhaust pipe, if you can't
get the potato out quick enough the engine stops ... no magic there.

Exactly. That is what I've been getting at all along. If vacuum starts
going down, you have to start redcing steam in.


There is no need to "shut down" if you completely lose vacuum,
everything shuts down all by itself ... especially if you are relying on
SSTG's for electrical power.

Sure, but hopefully you don't let it get that far.

...Have been faced with losing vacuum many
times but have never seen or heard of having to shut a plant down in
order to restore it ... most vacuum comes from the condensation of steam
in the condenser so stopping all that steam from entering is the worst
thing you can do.

Never had a condenser get a slug of air from the glands? Never flooded
the hotwell when a condensate pump craps out?

Anyway, if you keep dumping too much steam into a condenser as it loses
vacuum, it can get really hot and make it difficult to restore vacuum
without shutting down and starting over with the air ejectors.

I make no bones that most of my experience, and all my training, was in
the Navy, which practices these things regularly and tends to run all
drills out to their end point. It looks to me like we agree on many
things but have widely different experiences in widely different plants.

Regards
Doug King