From: 01crmeyer@leo.bsuvc.bsu.edu (Craig Meyer)
Newsgroups: sci.energy
Subject: Re: steam electric hybrid ...
Date: 23 Nov 92 17:42:42 GMT
Organization: Ball State University, Muncie, In - Univ. Computing Svc's


> How big would a steam turbine and generator be for, say 10-15 kW?
> 
> I would expect it to be far smaller than the mass of batteries
> it would replace in a pure electric car.  

It's the boiler that takes up the most space, not the turbine.
  
> So where are the technological 'gotchas'?  
> 
> Complexity?  

You bet it'd be comlex, in order to even match the efficiency of an IC.  Sure,
we could make a simple, big one like the GM SE 101 (which was pretty darn
complex in itself, mind you), but that woulnd't be as efficient as an IC.
                                                                         
> I can't quite see how a simple steam turbine/generator with
> flash boiler for 10 kW could be any more complex than a modern IC engine
> with turbo & intercooler & smog gear & ...  

You're right there, though.

> Heck, wasn't the Tesla design
> for a turbine just recently reserected by someone in a new and improved
> form?  (It was, basically, a set of disks on a shaft with steam spiraling
> radially between the rotating disks.  Very simple...).

Whoa, hyah!

I read about those things a year ago, too.  But since it recieved so little
attention, I guessed that it wasn't very efficient.  'Just couldn't believe
that it'd work, I guess.

Please do tell, WHAT'S THE SCOOP ON THE TESLA TURBINE?!

> Efficiency?  Fuel being burned external to the boiler will burn cleaner,
> but do you loose too much energy in the boiler/turbine/generator/motor,
> and occasionally battery charge/discharge, cycle?

All depends on the operating temperature, it seems.  You know--Carnot and all. 
Getting the temp up there will take some work, though.  But hey, work happens.

> Given that commercial power steam plants can get to very high efficiencies
> I have trouble believing that this is a killer... but maybe it would
> cost too much to make small plant that efficient?

That's my guess.  The central station turbines have DOZENS of stages--thousands
of buckets (blades)

> The idea of an external combustion generator onboard an electric 
> hybrid solves a bunch of problems (low smog, lighter weight than
> an all-electric, good acceleration from batteries, good efficiency
> from turbine, long range on fuel, all-electric mode for short trips, etc.)
> so where does it fall down?

Well, just how practical is the hybrid concept at all, anyway?  Knee-jerk
engineering tells me that the added complexity and cost of a fuel-driven
prime mover AND an electrical system makes it all look silly!

If the steam system is clean and efficient, why bother with the batteries?  
(I know this a pretty juvenile question, but I'd appreciate the advantages of
hybrid systems laid out in from of me.)

       Craig Meyer                 01CRMEYER@LEO.BSUVC.BSU.EDU
       Indiana Academy for Science, Mathematics, and Humaities.
       Muncie, IN  47306                          317-285-7433

       Opinions expressed are mine alone, and not necessarily
       shared by the Indiana Academy.
Newsgroups: sci.energy