Nav wrote:

I think it's also pretty
sloppy to call the inlet prssure to a turbine a vacuum. Don't you guys
traditionally use mmHg for near vacuum pressures?

We sometimes us inHg and sometimes we use psia, depends on the
shipbuilder and machinery supplier. It is reasonable to assume a metric
ship displays mmHg ... makes no matter as far as operation is concerned.

It is hardly "sloppy" to call inlet pressure the condenser a vacuum. It
is engine exhasut and as long as it is less than atmospheric it is a
vacuum.

Condenser pressure is engine exhaust pressure for engineering purposes.
We determine condensate depression and other operational factors by
calculating condenser vacuum based on exhaust temperature.

Rick

Rick wrote:
We determine condensate depression and other operational factors by
calculating condenser vacuum based on exhaust temperature.

Here's a good homework question for Navvie/Navjax/Navsprit:

Define "condensate depression" and explain it's significance in steam
plant operations.

DSK

DSK wrote:

Rick wrote:

We determine condensate depression and other operational factors by
calculating condenser vacuum based on exhaust temperature.


Here's a good homework question for Navvie/Navjax/Navsprit:

Define "condensate depression" and explain it's significance in steam
plant operations.


Good lord. How childish. No wait, it's a genuine question right? Well
Doug, it's a temperature difference that is impoertant to overall
thermodynamic efficiency which can be defined as P/Qh-Qc. For a steam
plant, the steam temperature and it's dryness fraction times the mass
flow rate determine heat fluxes in that equation.

Yes Doug, I did freshman thermodynamics. Did you?

Cheers

Nav wrote:

Good lord.

That may not be the response you were looking for ...

You guys have fun, it is time to bow out of this one.

Rick
USCG Chief Engineer
Steam/motor/gas turbine

Define "condensate depression" and explain it's significance in steam
plant operations.


Nav wrote:
Good lord. How childish. No wait, it's a genuine question right? Well
Doug, it's a temperature difference

Right.

Where?

I mean, between which two points in the steam cycle?

... that is impoertant to overall
thermodynamic efficiency which can be defined as P/Qh-Qc.

How else could it be defined, in more everyday terms?

... For a steam
plant, the steam temperature and it's dryness fraction times the mass
flow rate determine heat fluxes in that equation.

Yes Doug, I did freshman thermodynamics. Did you?

Yep. But your answer is mostly gobbledy gook to me. What's a dryness
fraction? Are you saying that condensate depression relates to degree of
superheat?

Rick can you make any sense of this?

DSK

DSK wrote:

Yep. But your answer is mostly gobbledy gook to me. What's a dryness
fraction? Are you saying that condensate depression relates to degree of
superheat?

Rick can you make any sense of this?

You both have really muddled and overcomplicated the issue.

Condensate depression is simply the difference in temperature between
the temperature at which steam will condense at the pressure existing in
the condenser and the temperature of the condensate in the hotwell.

Too much cooling (beyond about 10* below condensation temperature) means
that BTU's are needlessly tossed overboard and must be replaced by
burning expensive fuel.

Rick

Rick wrote:
You both have really muddled and overcomplicated the issue.

All I did was ask the question.


Condensate depression is simply the difference in temperature between
the temperature at which steam will condense at the pressure existing in
the condenser and the temperature of the condensate in the hotwell.

Absolutely & precisely correct.


Too much cooling (beyond about 10* below condensation temperature) means
that BTU's are needlessly tossed overboard and must be replaced by
burning expensive fuel.

Yes.... although the Navy cares less than they should about fuel
economy. We used to shoot for 5 degrees.

Here's a fun thought... let's list all the unexpected things found in
main condenser headers. How about a case of beer (unfortunately mangled
& empty)?

Fresh Steam
Doug King

Rick wrote:

DSK wrote:

Yep. But your answer is mostly gobbledy gook to me. What's a dryness
fraction? Are you saying that condensate depression relates to degree
of superheat?

Rick can you make any sense of this?


You both have really muddled and overcomplicated the issue.


It's Dougs fault. He always does this (asking ever more arcane
irrelevant questions) when when he's painted himself into his corner of
ignorance. He goes on and on until he finds something that you can't be
bothered to answer and then he'll jump around the playground claiming he
scored some point. I can see he's trying to do it to you now...

Cheers

DSK wrote:



... For a steam plant, the steam temperature and it's dryness fraction
times the mass flow rate determine heat fluxes in that equation.

Yes Doug, I did freshman thermodynamics. Did you?


Yep. But your answer is mostly gobbledy gook to me. What's a dryness
fraction? Are you saying that condensate depression relates to degree of
superheat?



You claim to have done freshman thermodynamics in engineering and you
don't know what the dryness fraction is? How strange. Perhaps you had
better look it up -'cos I know nothing! Try a google and you'll learn
some freshman engineering on steam plants.

Cheers