[ExI] Electric cars without batteries

[spike]

> -----Original Message-----
> From: extropy-chat-bounces at lists.extropy.org 
> [mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of 
> Keith Henson
> Sent: Sunday, October 24, 2010 7:14 PM
> To: ExI chat list
> Subject: Re: [ExI] Electric cars without batteries
> 
> On Sun, Oct 24, 2010 at 5:14 PM, spike <spike66 at att.net> wrote:
> >
> >> ...On Behalf Of Keith Henson
> >
> > Well OK Keith, I need to do some more work on this idea 
> then.  I just 
> > can't imagine a gas turbine spinning slowly enough to have 
> any kind of 
> > generator hold together.
> 
> Steam is a gas, virtually all of the large steam and gas 
> turbines turn at 3600 RPM...

Oooookaaaaaayyyy, now I know why we were talking past each other.  Ja, steam
turbines can be made to turn slowly, but we are talking about two completely
different things.  Steam is cold.  Even superheated steam is cold.  Products
of hydrocarbon combustion are hot.  A steam turbine is a big thing, good for
power generation, not good for carrying around to generate power in a
Detroit.

OK no problem, proposal: let's see if there are any steam turbines of 20-ish
kw, I will estimate the boiler needed to make the steam and the condenser
requirements (because that will be possibly as big and heavy as the rotor if
not moreso) and I think we will both see why this notion has never been used
as far as I know for automotive use.  If instead of a condenser, we throw
the low pressure steam overboard after it passes the turbine, the idea would
require too much water mass for a typical trip.

> Next time you have the hood on a vehicle up, take a look at 
> the diameter of the alternator and the driving pulley on the engine.
> Typically the ratio is from 4 to about 7.  So if the engine 
> red lines at 4500 RPM, the alternator speed would be 18,000 
> to 31,500 RPM.
...
> Keith

Hmmm, well OK, with those numbers we should be able to get these two to meet
somewhere in the middle.  With that in mind, we might be able to get a hot
gas turbine to run efficiently down at 30kRPM and a generator that can
sustain those speeds without overheating.

spike