Re: [Starlink] some post Starship launch thoughts

[Dave Taht <dave.taht@gmail.com>]

On Wed, Apr 26, 2023 at 1:41 PM Rodney W. Grimes
<starlink@gndrsh.dnsmgr.net> wrote:
>
> > As always I enjoy the flood of information we get on this list!
> >
> > still, so far, my research on a nitrogen deluge system (instead of
> > water) has come up empty for me, except as a fire suppressant. So it?s
> > either crazy or brilliant. Or both! I really liked the idea of
> > something cooler that was a natural byproduct of the LOX process...
>
> I dont think cooler does much, isnt it the "energy of vaporization"
> that is actually doing all the "work" in this type of system?
>
> H2O is 40.7 kJ/mol and LN2 is 5.6 kJ/mol so you would
> need ~7 times as much LN2 to do the same work.

Now that! was the kind of numbers I was looking for!

Still, water has to come from somewhere, and be stored. I will keep
thinking about it. I like that they seem to think that a water cooled
steel plate will suffice.

> And the reason N2 is used as a fire suppressant is again not
> because of temperature, but because it displaces the O2 and
> suffocates the fire.  N2 is also easier on our ozone layer
> than the prior used Halon.  Finally, this is usually
> compressed N2 gas, not LN2.
>
> --
> Rod Grimes                                                 rgrimes@freebsd.org


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