Re: GAS-L: efficiencies of steam engines

[Peter Singfield <snkm@btl.net>]

Bare with me Skip -- we'll be crossing into that territory soon. Your right
about the price of the turbine. Your right about using waste furnace heat
for fuel drying and preheating combustion air. But using a condenser -- do
not expect steam exhaust temps to be high -- as you will see in the
following days.

I have in front of me a complete set of quotes with all the math for a 3
mwe biomass cogen plant (Citrus peels). 

So I can give you all the real figures. We go at this bit by bit -- until
it is well understood.

The great loss in efficiency is not in flue gasses -- but turbine "steam"
exhaust -- it always is!

I am also getting a lot of input from the "other" list (Tesla turbines).
Just of the top of my head -- it appears there is no more than a few
percent dif in efficiencies. But the price of a Tesla Turbine would be only
a fraction of the equivalent blade turbine. And yes -- they multi stage
Tesla turbines to do that.

I have also been referred to a new innovation -- a rotary engine. At first
glance it looks like a mechanical monster. I remember designing and
building a prototype sliding vane motor 32 years ago -- that was very
simple to make and reliable. 

Think of a hydraulic vane pump -- but with special body curves. I do
believe that is  just the right combination of piston and turbine
technology. Smooth rotary motion -- well balanced for high RPM. A rotary
design is always a unaflow -- by the way. These can be built very small --
and much easier than any piston engine. Wish you were here with your shop
Skip -- I'd turn one out for you in a couple of days.

In the example I will be giving -- it is a fire tube boiler over a gasifier
furnace bed. Very relevant to the interests of this list.

I was wrong about the pressure and temps. But not much -- pouring over all
the specs -- I see it is 400 psi and 750 F.

This is a "plant" that is 3rd world oriented. Small!

I plan to use this as a "practical" example for our present discussions. 

I just have to find the time to write this book. So patience --

Peter in Belize or:

Peter Singfield
COROGEN
Executive Director
Xaibe Village
Corozal District
Belize, Central America
Tel 501-4-35213
E-mail: snkm@btl.net




At 05:46 PM 3/15/00 -0600, you wrote:
>Peter, you should consider a couple of things.
>There is no such thing as an efficient impulse turbine.....at any size.  The
>efficiency comes from going into reaction turbines (and boy does that get
>expensive).
>
>If you want to capture lost heat, a good rule of thumb is that everything
>under 600 degrees both boiler and engine exhaust, should be used to heat
>combustion fuel and air.  It is also cheaper.
>
>Skip
>www.sensiblesteam.com
>
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The Gasification List is sponsored by
USDOE BioPower Program http://www.eren.doe.gov/biopower/
and PRM Energy Systems http://www.prmenergy.com
Other Sponsors, Archives and Information
http://www.crest.org/renewables/gasification-list-archive
http://solstice.crest.org/renewables/biomass-info/gasref.shtml
http://www.crest.org/renewables/biomass-info/
http://www.crest.org/renewables/biomass-info/carbon.shtml