Acknowledgemnt:
Some of the contents on this page have been adapted from
Wikipedia > Stirling Engine Open Source Encyclopedia; June 15, 2004
Preface
"There are lots of little advantages that can be played with Stirling
engines and phase change materials, but in general there is nothing there for
utilization that will boost us to a higher level of energy utilization.
"What the world could use to good advantage is a cheap Stirling
design. Don't know of any great ones. I only know of Dean Kaman's
design with Decca Engineering (I think it is called, or Deka?) in Manchester,
NH. Cheap and simple, but not cheap and simple enough."
-- Ken
Rauen, PES Network Inc, Science Advisor (Feb. 9, 2006)
World's
largest solar installation to use Stirling engine technology -
20-year purchase agreement between Southern California Edison and
Stirling Energy Systems, Inc. will result in 20,000+ dish array
covering 4,500 acres capable of generating 500 MW, more than all other
U.S. solar projects combined. (PESN; Aug. 11, 2005)
Stirling
Energy Systems - Developing equipment for utility-scale
renewable energy power plants and distributed electrical generating
systems. Their most remarkable achievement is the recent contract with
Southern California Edison to install a 4,600-acre solar system that
will generate 500 megawatts. (PESWiki; Aug. 11)
Sunpower
Unveils 2007 Micro Co-Generation Technology - Device uses
Stirling engine to efficiently use natural gas to generate heat and 1
kW of electricity. Designed for kitchen installation in Europe. Brings
distributed energy concept home. (PESN; Mar. 3, 2006)
WhisperGen
Gearing Home Use - Whisper Tech has received a $300 million
contract to supply tens of thousands of its WhisperGen
units to homes in the UK. Powered by natural gas, it provides
electricity and heat at a cost savings and cut in CO2
emissions.
Feasibility > Could
a 200-year-old engine solve today's petrol crisis? - a leading
expert on the Stirling engine has claimed it could reduce petrol and diesel
consumption in motor vehicles by more than half. "The problem was that
it would cost a pile of money to re-tool up to build Stirling engines."
(The Scottsman; June 5, 2004)
Open
Sourcing > Stirling
Engine -- Simplified Plans - Collection of proof of concept
designs that you can build for as little as $99. "This
small-scale model situated on one boiling cup of boiling water and
cooled by a cube of ice, can turn for 35 minutes." English
translation of photologie.net French site, by Pure Energy Systems.
Book > Around
the World by Stirling Engine by Brent H. Van Arsdell Probably the best general book on Stirling engines. Explains how
Stirling engines work. Covers all the current power producing
uses of Stirling engines along with how to contact the people who
build them. Covers everything from Stirling engines in military
submarines, to a Stirling engine that powers the rotisserie for an
Oklahoma mechanic's barbecue.
The Stirling engine was invented in 1816 by the
Rev. Robert
Stirling who sought to create a safer alternative to the steam
engines of the time, whose boilers often exploded due to the high
pressure of the steam and the primitive materials of the time.
Stirling engines convert heat (actually, any temperature
differential) directly to movement: they use a displacer piston to
move enclosed air back and forth between cold and hot reservoirs. At
the hot reservoir the air expands and pushes a power piston,
producing work and displacing the air to the cold reservoir. There
the air contracts and pulls the power piston, closing the cycle.
In more sophisticated Stirling engine a regenerator,
typically a mesh of wire, is located between the reservoirs. As the
air cycles between the hot and cold sides, its heat is transferred
to and from the regenerator. In some designs, the displacer piston
is itself the regenerator.
Stirling engines can also work in reverse: when applying motion,
a temperature differential appears between the reservoirs.
Incidentally, one of their modern uses is in supercooling. However
they are difficult to construct and require precise machining, and
thus never replaced the steam engine despite being much more fuel
efficient than steam engines or even the modern internal combustion
and Diesel engines.
Stirling engine types
Stirling Engines come in three distinct types:
An alpha Stirling contains two separate power
pistons, one "hot" piston and one "cold"
piston. The hot piston is situated after the higher temperature heat
exchanger and the cold piston is situated after the low
temperature heat exchanger. This type of engine has a very high
power-to-volume ratio but has technical problems due to the
(often) high temperature of the "hot" piston and its
seals.
A beta Stirling has a single power piston
arranged coaxially with a displacer piston. The displacer piston
does not extract any power from the expanding gas but only
serves to shuttle the working gas from the hot heat exchanger to
the cold heat exchanger. This engine does not require moving
seals in the hot portion of the engine and can achieve high
compression ratios due to pistons being able to overlap in their
motions.
A gamma Stirling is simply a beta Stirling in
which the power piston is not mounted coaxially to its displacer
piston. This configuration produces a lower compression ratio
but is often mechanically simpler and often used in
multi-cylinder Stirling engines.
StirlingEngine.com
- Features array of kits, includes instructions of how to build a
Stirling Engine (from a kit). SeeSan
Diego Union Tribune feature article June 1, 2004: "Stirling
engines, invented nearly 200 years ago, are being built by North
County man."
NewEnergyShop.com
/ Sterling-Engines.net - " Sophisticated demonstration
models, using alternative energy technologies for
universities, schools and interested individuals like Stirling and
Steam engines, fuel cells, photovoltaic objects, toys and more."
From: ken rauen Sent: Tuesday, June 15, 2004 10:51 AM
Stirling engines qualify for "free energy" designation when they allow
us to tap previously inaccessible sources of naturally occurring energy.
Stirling cycle engines are very efficient for a given temperature difference
between the heat source and the heat sink. Actually, steam engines (the Rankine
cycle) fall into this category, too; depending upon what kind of hardware and
its maintenance you prefer, one or the other will be preferred. Steamers have
fewer parts and higher power density. Other fluids, such as a variety of
refrigerants, can be used instead of water. Stirlings avoid fluid containment
problems, as they can run with air as the working fluid, and will have less
maintenance issues.
Solar collectors are a source of low grade thermal energy that has largely gone
untapped for electricity. Mount Stirlings of a variety similar to what is show
in the aforementioned website, though more robustly designed and constructed,
along the back wall of a solar collector, and let the cold side of the Stirling
engine bank radiate the waste heat into the shade. 100 W per square foot
insulation can translate to almost 10 W/sq ft of electricity with the hot side
of the collector reaching only 150F with ambient T at 70F. No high-tech
materials are needed. A 25 square foot collector can generate about 200 W of
cheap electricity! This competes with solar cells.
Steamers can utilize this size very well with a tube boiler and just one
expander connected to one generator. I recommend a "steamer."
(Good
information to builders:) Why Aviation Needs the Stirling Engine by Darryl
Phillips, main
address(http://www.qrmc.com/),
mirror
Quote: "...This 4-part series appeared in the March 1993 through March
1994 issues of Stirling Machine World...Common four cylinder engines such as
Lycoming and Continental show torque that varies from a negative 100% to a
positive 350% of the nominal torque...A Stirling with the same number of
cylinders and identical power has a torque variation of +/- 5%!..."
Quote:
"...This Stirling Engine with 8 cylinders is twice double acting.
Its special highlight is the facility for the heat transfer from a liquid [eg.
water] to the working fluid [eg. air] which results in extremely low
temperature losses....Because of the nearly isothermalized heat transfer the
efficiency is near carnot's ..."
World's
largest solar installation to use Stirling engine technology -
20-year purchase agreement between Southern California Edison and
Stirling Energy Systems, Inc. will result in 20,000+ dish array
covering 4,500 acres capable of generating 500 MW, more than all other
U.S. solar projects combined. (PESN; Aug. 11, 2005)
Stirling Engines > Segway
Inventor Focusing on Green Cars - Dean Kamen has spend over
$40 million in the last decade developing stirling engines technology,
and now appears to be developing a green car using that technology. (EcoGeek;
Aug. 11, 2007)
The
Stirling and Miller-Cycle Engines Quote: "...The main advantage of
the Stirling engine is that it is remarkably efficient. It extracts up to 50
percent of the possible mechanical energy contained in the fuel it uses,
compared to a high of about 25 percent for a standard internal combustion
engine (ICE)..."
EMF Safety Store
LessEMF.com is the place
to buy Gauss meters, RF
meters, shielding.
ADVISORY: With any
technology, you take a high risk to invest significant time or money
unless (1) independent testing has thoroughly corroborated the
technology, (2) the group involved has intellectual rights to the
technology, and (3) the group has the ability to make a success of
the endeavor.
All
truth passes through three stages:
First, it is ridiculed;
Second, it is violently opposed; and
Third, it is accepted as self-evident.
--
Arthur Schopenhauer (1788-1860)
"When you're one step ahead
of the crowd you're a genius.
When you're two steps ahead,
you're a crackpot."
Ready-built
unit of dimensions 3.5 x 5 inches. "This little charmer
will run on any warm surface (the warmer the faster), even the palm of
your hand and, amazingly, backwards (anticlockwise) on a shallow tray
of ice cubes."
