Info on modern steam engines? 2

[FEMdude]

Well, as petrol price is now over 8$/gallon (here in Europe), I am going to replace my stationary engine/generator by steam piston engine (3-10kW output).

I have been looking for information on the latest developments in steam engine design, but it looks like they haven't changed much since late 1800s, allthough materials and manufacturing technologies have developed a lot.
However I know, that at least in 1960 they manufactured rather efficient small steam engines in Hambur Spillingwerk Germany, and that several car manufacturers did some good work during oil crisis in early 1970s.

Any suggestions where to find technical information on these systems or on more recent ones? Google gives pages only for hobby engines, or home built ones, which are not very reliable or efficient.

 

[chief]

CHECK OUT 'Marine Steam Engines & Turbines' Author S.C. McBirnie, Published by Butterworths 4th Edition 1980.
Probably out of print, but will be available on Amazon. Good article on the 'Hamburg' engine, which incidentally includes an exhaust turbine.

Offshore Engineering&Design

 

[rmw]

Seems like I remember that Skinner Engines were going to revive the use of steam engines back about the mid '80's.

I did a google of "Skinner Engines" and found some interesting reading.

Start there and see where it takes you.

rmw

 

[FEMdude]

Thanks for your tips, they are much appreciated!

It looks like BMW have managed to make a small steam engine (10 kW) which uses waste heat from exhaust gases:

http://www.mwerks.com/artman/publish/bmw_news/article_921.shtml

or us patent 6834503 in

http://www.google.com/patents?q=6834503

If they get it working properly in a vehicle, it really should not be too difficult to even improve it in stationary power station use, as weight, size or hermetic sealing is not an issue any more?

 

[MJCronin]

FEM dude..

You do, of course, realize that you are embracing an inefficeint 1890s technology with the steam engine.. . ?

Virtually no one is producing piston driven steam engines because of thier inherent limitations when compared with the modern steam turbine.

http://en.wikipedia.org/wiki/Steam_turbine

If you can get a source of fuel, clean water and a condenser, then a small turbine may satisfy your needs.

My opinion only

-MJC

 

[rmw]

While I have had no contact with them for years, what I remember about Skinner's approach to getting back in the business was that at the tail end of lots of processes is lots of low pressure steam that is just too low to be efficiently utilized by a steam turbine. They thought that they could utilize their type of engine inefficient as it is because of the large cross sectional areas of the engine's piston. Fifteen PSI steam can produce a lot of work in one of those babies.

I guess the world just wasn't ready for them at that time.

There were some of those beauties (not necessarily Skinner) still running when I was just a pup entering the engineering world. Boy what a rush; chook plop, chook plop.

rmw.

 

[FEMdude]

MJC,
Steam turbine is less efficient than piston engine in power level under 500-1000 kW due to poor Reynold's number. The reason why some piston engines are less effective is that they are either copied from 1890s design, or poorly constructed, whereas turbines have been intensively developed for the last 100 years.

In 1968, they manufactured a piston steam engine for car, which had operating effectivity of 30% (680C steam temp). This has been documented in "90th congress second session on the automobile steam engine... number 90-82", which I unfortunately don't have. This efficiency is very similar to modern gasoline cars, and only slightly smaller than in turbo diesel cars.

With modern material and technologies, I still have every reasons to believe that pressure and temperature can be further increased in piston steam engine. Even with 1890s technology, the $-efficiency in my use would be superior to gasoline, as I can get wood for free, but have to pay terrible taxes for gasoline.

 

[chief]

The limitations of the reciprocating steam engine were mainly caused by the inherent inefficiency of the cycle and the unavailability , at that time, of an effective cylinder oil to withstand the high superheat temperatures, when they attempted to push the envelope of development using higher pressures and superheat.
The addition of the Bauer-Wach exhaust turbine helped to improve the cycle efficiency a great deal.
The 'Hamburg' engine incorporated all these developments, but was overtaken by the oil crisis of the 70's.

Offshore Engineering&Design

 

[davefitz]

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