Re: [PSUBS-MAILIST] Hydrogen Fuel Cells coming closer for Psubs?

[MerlinSub@t-online.de (Carsten Standfuss)]

I was thinking to use the fuelcell only underwater and vent via a
ventilation system the heat all over the compartments. 

But with a - say using of about 30-40 Kw FC Power for the drive ..
the fuelcell will produce still 20-30 KW heat - to much to heat only the
compartments. So there should be something like a watercooled
heatexchanger. So I am able to control the heatwater flow with a vale in
both directions : Inside to the heating system or dump outside via a
closed keelcooler pipe. 

Maybe I can use the watercooling system of the diesel for this - because
the diesel is not running underwater- and the FC not on the surface. 

For the Euronaut the fuelcell heat system will be a good solution 
- because on deep dives with using the diverchamber - the chamber will
be filled with about 30° warm helium to keep the divers alive.. 
.. and this compartment has no insulation. 

regards Carsten


Ian Roxborough schrieb:
> 
> On Thu, 05 Dec 2002 22:53:05 +0100
> MerlinSub@t-online.de (Carsten Standfuss) wrote:
> 
> > - heat.. a 1000 watt fuel cell with a efficency of say
> >   50 % produce also 1000 watt heat..
> >   if they build something with 75 % you get still 333 watt heat.
> 
> I was thinking about the heat problem and I wonder if
> there is anyway to usefully recover the heat from the fuel
> cell, for heating the crew compartment or heating fresh water
> for tea or coffe or a bathing.  I would imagine it would be
> useful to beable to dump the heat over board as well.
> With a well thought out heat exchanger system you could have
> a comparement heater, a water heater and an external heater
> to removing excess heat, all powered from the heat of the fuel
> cell(s).
> 
> Ian.
> 
> 
> > Ian Roxborough schrieb:
> > >
> > > On Thu, 5 Dec 2002 14:29:54 -0600
> > > David Buchner <buchner@wcta.net> wrote:
> > >
> > > > Coooool! Can't you get hydrogen cylinders from places that do welding
> > > > gases? Maybe I imagined that. But it does have to be straight-up
> > > > hydrogen, not methane or propane (or acetylene?) or other more popular
> > > > and available fuel, like some ideas I'd heard of. Hm. Like
> > > > hydrogen-fuelcell cars, that becomes a "they don't sell that around
> > > > here" type of problem.
> > >
> > > I don't think you cold use anything but hydrogen in this model.
> > > Finding H2 might be a big problem,  I know the fuel cell's proton
> > > exchange membrane is sensative to polutants in the hydrogen
> > > and will loose effiency and finally fail with no way to clean
> > > the membrane (it's too fragile).  The web page says you need to
> > > use Fuel Cell grade hydrogen, which is probably very pure, I
> > > don't know, but I would guess wielding shop hydrogen might not
> > > be pure enough.
> > >
> > > There is a 'Fuel finder' on the website, the closest to me
> > > is about 50 miles a way.
> > >
> > > The website also mensions ventilation systems so they may
> > > be other problems to solve before one could be using in
> > > a Psub.  I might be pretty dangerous to operate one in the
> > > same compartment as a person.  Also I've not found out
> > > how much O2 these things use.
> > >
> > > Ian.
> >