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

[Guy Morin <xnet@videotron.ca>]

The use of a fuel cell does provide it's own solutions.

The heat comes out mostly in the form of hot water. The water
produced by the fuel cell has to be ejected outside the sub
anyway, either via the bilge, or a dedicated pumping system.

BTW, a 30-40 kW fuel cell is considerable. Not so much in
terms of the unit itself, but in terms of the fuel storage
requirements, more specifically the oxygen.

There are other factors to consider as well in terms of
energy storage. Some products have been successfully used
with liquid fuels. A catalytic reaction is used to convert
the liquid hydrocarbons into hydrogen, and CO2. Such systems
could reduce the requirement for compressed gas storage
to oxygen only.

Guy


Carsten Standfuss wrote:
> 
> 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.
> > >