OT Nuclear U-Boats; how do they condense the steam?

After following the Vigil TV series (with all its
reported errors) and also the prog on HMS Trenchard,
when a Brit U-boat is powered by nuclear fuels, how
do they condense the steam?
With sea water? If so, there must be difficulties
in sealing the intakes and outfalls from deep sea
pressures.
Perhaps the steam is heated to 200C and only cools to
100C through the turbines before recirculating
so no condensing is
required. This, of course, will be wasteful
of some thermodynamic energy, but there's so much
in reserve in the nuclear fual that perhaps it does not
matter.
Reply to
gareth evans
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As an aside would you recommend Vigil? A friend of my said the submarine looked like a free gift from a cornflakes packet.
Reply to
Scott
Sea water heat exchanger
The main engineering problem seems to be keeping it from making detectable noise while the boat is running in quiet mode.
Reply to
nightjar
very good thrilling plot (unlike Star Wars which I got less than half way through before giving up on it)
Reply to
gareth evans
That doesn't seem to be an issue, judging by the Vigil films. There's a tannoy system that must be audible miles away, and the crew seem to shout at each other the whole time. What difference would a little gurgling from the reactor make?
Reply to
GB
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Reply to
Spike
I'm talking about real life :-)
However, there is a high power setting fro the coolant pumps, which is relatively noisy. That is used when maximum power is more important than stealth. It is also used when leaving port, as it prevents any spy or spy ship from listening for the boat's silent running signature.
Reply to
nightjar
Tell the authors, not me!
Reply to
GB
:)
That's interesting. I wonder what happens if they forget to do that once? Do they scrap the fleet and buy a new one? If so, it would be quite an expensive mistake.
Reply to
GB
Could they not just alter one of the components, preferably the noisiest one?
Reply to
Scott
Nah! If you're going to do the job, do it properly.
If I had the choice between several dozen new hospitals and a fleet of new nuclear submarines, I'd want to be equipped to start a nuclear war we couldn't survive. Wouldn't you?
Reply to
GB
The more nukes we have deployed the less chance there is that anyone will survive a nuclear war. We have the ability right now to destroy civilization as we know it.
The old saying is "If the next war involved a full nuclear exchange, the war after that will be fought with rocks and sticks".
Reply to
gfretwell
The whole point is that having nuclear armed submarines at sea means that no-one can attack without potentially suffering a retaliatory attack. Hospitals are of no use if someone decides to obliterate your country, knowing that there will be no response.
While it would be better if no countries had nuclear weapons, while some potential enemies do, it makes sense to have your own response of last resort.
Reply to
Steve Walker
Some of the CGI is very good, other stuff is pretty awful.
Reply to
newshound
I'm guessing these will be conceptually similar to those used by conventional power plant, which has an array of tubes about 3 inches in diameter (with similar spacing) through which the seawater passes. In the old days these would have been a copper alloy (good for anti-fouling), now I expect they will be titanium for better corrosion resistance.
1000 feet is about 30 bar / 450 psi, a relatively modest figure for unfired pressure vessels. Obviously, the tube-plates have to be properly designed.
The steam temperature in a commercial PWR is a bit over 300 deg C and I expect the submarine figure is comparable. They will probably be aiming for a condenser temperature around 30 deg C, giving a pretty good vacuum (about 30 torr). A surprising proportion of the energy in a steam turbine is delivered by the Low Pressure rotor(s).
Reply to
newshound
Yes, I think GB is suffering from the "why have nuclear subs with missiles when we aren't going to use them?" syndrome. He overlooks that they have been in use, 24x7, for the last 50 years or whatever it is.
Reply to
Tim Streater
I wonder how they deal with the thermal signature of that much heat being released back into the sea?
It almost makes me wonder if they are not making more of an effort to scavenge that energy, not because they need it but just because they don't want to leave a heat trail.
Reply to
gfretwell
The BIG issues for me about Nuclear conflict is it starting accidentally someone getting a bit trigger happy almost happened in 1979 wasn't it?, some Russian bloke queries odd radar returns instead of referring to higher up the chain, which from what had happened would have provoked a retaliatory strike!..
Nope 1983!, Stanislav Petrov
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Reply to
tony sayer
The Argentinians attacked the Falklands, without us obliterating BA. What better target to attack than one that cannot retaliate?
By not turning the whole of Argentine into radioactive glass, our so-called nuclear deterrent lost all credibility. So, we might as well scrap it. Clearly, if we won't nuke the Argies, we certainly won't nuke the Ruskies.
Reply to
GB
A god-forsaken set of islands with 2000 inhabitants? Not exactly Pearl Harbour, was it.
FFS
So, we might as well
Reply to
newshound

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