From: 01crmeyer@leo.bsuvc.bsu.edu (Craig Meyer)
Newsgroups: sci.energy
Subject: Continuing Steam-Car Discussion
Date: 19 Nov 92 14:03:50 GMT
Organization: Ball State University, Muncie, In - Univ. Computing Svc's


> Steam engines normally use the wet steam as a cylinder lubricant. 
> No additional oils are required. The "rings" are normally leather
> wetted by the steam. In old locomotives, they lasted 6 months of
> *continous* hard pulling between servicing. Remember that a piston
> steam engine develops maximum torque at stall and is a low RPM 
> device. Bearing lubrication can be a simple drip oiler.

All I know is that the passage about the GM SE 101 steam car (in an
industrical-arts textbook) said that they had to mix the lubricants with the
steam at "elevated temperatures and pressures" and then separate it from the
steam before heating.

And that thing ran at just 370C (My mistake saying it was 700C)

This may be good news, though, in that they WERE able to deal with it.  It may
have been tricky, but they were SUCCESSFUL in lubricating the engine, albeit
further development could perfect the system.

Does this offset one of the big problems of 800C steam--lubrication?

Could corrosion be successfully fought with newer corrosion-resistant
materials?


> That's hard to say. The very best superheat compound cycle steam plants
> have an efficiency of around 50% while the best IC engines have an 
> efficiency around 28%. To approach a big compound plant in a car though,
> that would be really tough. I'd *guess* from what I've read that the
> steam plant would be about 30% worse than the IC plant for the same
> peak horsepower. One thing should be noted, however, the characteristics
> of the two engines are wildly different and a lower peak horsepower steam
> plant should offer the same driving characteristics as a bigger IC plant.

That looks like a prescription for delivery vehicles & buses.

Big-rigs would be big business, though.  I know the Carnot equasion and all,
but practically, would raising the working temperature from 370C to 800C have
a drastic effect on efficiency.  Carnot ideal for 370C: 36.7%  Carnot ideal for
800C: 65.2%.  (But if even the stationary plants have trouble cracking 50%, why
should we do any better, eh?)

 
>>3.  Given a closed system is there a better choice of working fluid than
>>water (Something that wouldn't freeze, and could act as a lubricant.)
> 
> Higher molecular weight fluids wouldn't
> develop as much pressure at the same temperature in a dynamic system.

News flash, folks:
Was leafing through a different book, trying to learn more about steam engines,
and there was a little paragraph about a automotive plant that used "an organic
fluid several times heavier than water" as a working fluid, which made for
"a smaller power plant."
                                          
I wonder just what it was!

CM
-- 
       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