Re: OT: Blast From The Past - steam - hot and cold
- From: "The Librarian" <zootwoman@xxxxxxxxx>
- Date: 30 Apr 2006 21:20:30 -0700
bring back the steam engine ;) First the Cold one
Cold engine powers car with efficiency
A source of pollution free and intrinsically safe motive power becomes
a practical reality after much effort. Tom Shelley reports
A car powered by liquid nitrogen may be seen cruising the streets of
Bishops Stortford. Cylinder injection of a heat transfer fluid followed
by liquefied gas has raised efficiency to a point where fuel costs are
comparable with petrol, but, more importantly, without the pollution.
As well as solving a problem which has long plagued all Rankine cycle
engines, it leads to pollution-free vehicles without the associated
cost and weight penalties incurred by batteries. They will also be
intrinsically safe - a matter of great interest to the oil and gas
industries. The idea of providing motive power from the boiling of a
liquid and the subsequent expansion of a gas has been around since the
end of the eighteenth century, steam power being the most obvious
proponents. However, it still suffered from the problems of heat
transfer which resulted in very poor thermal efficiencies. The only
answer to this problem is to have machines the size of power stations.
To give some idea of efficiencies, the most efficient steam locomotives
ever built, the American Union Pacific 'Big Boys', are said to have
attained 14% efficiency, while the best achieved in Britain was around
8 to 9%. Similar figures pertain to another idea kicked around for more
than a few years - the running of cars on liquid nitrogen which is
allowed to boil and expand using heat from the ambient environment. The
two liquid nitrogen powered developments most prominent on the Web are
one at the University of Washington, now abandoned, and one at the
University of North Texas. The best, the latter, seems to have achieved
power a car for 24km using 180litres of liquid nitrogen. Where all the
liquid nitrogen engines to date have fallen down is that while they
make use of the expansion effect of liquid nitrogen's boiling at 77°K,
they fail to make full use of the expansion of that gas from 77°K to
ambient 300°K, and keep it at ambient as it expands. The efficiency of
a heat engine depends on the difference between source and sink
temperatures being as far apart as possible. Failure to keep the
temperature of the gas up during expansion results in a heat engine
which is less than optimally efficient. A particular difficulty with
nitrogen is that, typical of gases in general, it is a good thermal
insulator, making it difficult to transfer heat into the gas unless it
is turbulent. One solution suggested by the University of Washington
was to make an engine using a lot of small cylinders, each only 10mm
across but with a 100mm stroke. Another of its ideas required building
a radiator into the cylinder head, and another, a 110kg external heat
exchanger. The University of North Texas suggests injecting a hydraulic
fluid into the cylinder along with the nitrogen, in order to provide an
internal source of heat and also lubrication. The University does not
seem to have ever either tried or developed this, but in making the
suggestion in a paper published in November 2001, the team put its
fingers on the breakthrough which Peter Dearman has been exploiting .
His engine is two stroke. The induction stroke starts by drawing in the
heat exchange fluid, which, in his case, is a conventional mix of
ethylene glycol based car anti-freeze and water. Liquid nitrogen is
then injected from a separate nozzle (if it was injected
simultaneously, the liquid nitrogen would freeze the heat transfer
fluid as it entered, blocking the injection port). The heat transfer
fluid possesses sufficient heat capacity to both boil the liquid
nitrogen and heat it all the way up to ambient temperature. The
pressure pushes the piston down and, as it does so, it absorbs more
heat from the heat transfer fluid, maintaining its temperature at
ambient. At bottom dead centre, the exhaust valve opens, and the
expanded nitrogen and heat transfer fluid are allowed to escape. Before
reaching the atmosphere, the mixture passes through a separator to
recover the heat transfer fluid which then passes through a radiator to
warm it up to ambient ready for the next cycle. The prototype 400cc
single-cylinder engine has been fitted into a Ford Orion. Dearman says
that it allows the car to be driven at up to 20mph and achieves a
mileage of 1mile/litre. At a cost from Air Products of 10p/litre, this
allows the car to achieve a similar fuel cost per mile to that achieved
using petrol. He expects a new two cylinder engine he is building to
raise maximum speed to 40 mph. Judging by the working engine model
shown on his stand at the British Invention Show, held at London's
Barbican Exhibition Centre, it looks relatively simple and inexpensive
to make being made from aluminium alloys. This contrasts with
conventional battery electric cars which tend to cost more than twice
as much as their conventional IC equivalents, and require additional
expenditure of around £100 per month in order to lease the batteries.
Furthermore, should the World suddenly turn to battery electric cars in
a big way, there is insufficient nickel to give them all either nickel
cadmium or nickel hydride batteries. Alternative lead acid batteries
are too heavy, and lithium based batteries are too expensive. The other
big advantage of liquid hydrogen powered engines over other
alternatives is that they are not only totally clean, but intrinsically
safe. This inspired great enthusiasm from one of the judges at the
show, who happens to work for a company with heavy commitments in the
oil and gas industry. It was probably this factor which helped Dearman
win both the Gold award in the industrial category and the Invention of
the Year title. The other niche market that Dearman had already
identified is the underground mining industry, which currently uses
either electric or diesel motive power, as appropriate. Liquid nitrogen
would offer considerable operating advantages over both. And for those
environmentally oriented, liquid nitrogen engines, being made of
aluminium, are easy to recycle, unlike nickel cadmium batteries.
http://www.eureka.findlay.co.uk/eureka_editorial/news_reference/FI-Nitrogen..htm
http://peswiki.com/index.php/Directory:Liquid_Nitrogen_economy
A Liquid Nitrogen (LN2) economy is a proposal for a future economy in
which the primary form of energy storage and transport is liquid
Nitrogen. It is proposed as an alternative to petroleum and as a means
of locally storing energy captured from renewable sources. An analysis
of this concept provides insight into the physical limits of all energy
conversion schemes.
Typically, the demise of the petroleum-age is presented as a
catastrophic collapse. The Liquid Nitrogen Economy is a proposal to
initiate an energy diversification, an alternative to the typical
collapse proposal.
http://www.sequencezero.com/L2N/L2NMap.html
http://www.aa.washington.edu/AERP/cryocar/Papers/sae98.pdf
http://www.pipeline.com/~bkyaffe/altfuel/section/n2.html
then the hot one
http://ghlin2.greenhills.net/~apatter/steamfaq.html
Steam Car FAQ's
1. Steam cars run on water.
No. - Steam engines are (external combustion, Rankine cycle) heat
engines. Water is the working fluid. They convert heat into mechanical
work. The internal combustion Otto cycle engine in your car does the
same. Both the internal and external combustion engines burn fuel
producing heat. The heat of that combustion raises the temperature of a
working fluid in a confined space producing an increase in pressure.
This pressure exerts force against a piston in the engine. The piston
moves turning the crank, turning the wheels moving your car along.
2. Steam cars are likely to explode.
No. - They are less likely to explode as they use less volatile fuels.
Modern steam generators for automotive use are constructed in such a
way that in case of a rupture they have vary little water at the
saturation point, preventing an explosion. The Stanley boiler, a
vertical fire tube design unlike modern generators have large amounts
of water at saturation temperature, was tested at the factory by forced
failure. The failure occurred in the fire tube expansion joints which
acted as a safely valve, safely releasing the pressure preventing an
explosion. Fred Marriott set a world speed record of 127.66 mph in 1906
in a specially built Stanley. In the following year he crashed while
trying to improve on his record. It was estimated that he was traveling
at 180 mph at the time of the crash. The boiler did not explode!! And
Fred luckily lived to tell the tail.
3. Steam is outdated and old fashioned.
No. - Most of our electricity today comes from steam engines. In atomic
power plants, steam is generated by the reactor and drives a steam
engine.
4. The internal combustion engine is used today because it is more
efficient.
No. - At the start of automotive development the steam engine had the
advantage. It was more powerful and easier to operate as it had no
transmission or clutch. Then the electric starter was invented. The
internal combustion engine was now a 'get in and go machine'. Steam
cars of the time needed a lot of preparation that required about 30
minutes or more before they could be driven. On condensing models
lubricating oil mixed with the water which then had to be changed every
other day or so. Very messy. Water also would get into the crank case
of the engine requiring monthly oil changes. Both types of automobiles
at the time where obtaining 8 to 13 miles per gallon of fuel. And the
steam car used less expensive fuel oil or kerosene. Today modern steam
power generating plants obtain 40% to 60% efficiency. The I.C.
automobile engine only gets 25% efficiency.
5. Steam automobiles can use a variety of fuels.
Yes. - Steam is generated in a boiler separate from the engine. The
combustion chamber in the boiler can be designed to accommodate any
combustible substance. The fuel is burned clean producing no more
pollution then a household gas heater. In an automobile the fuel would
have to be restricted to one that can be transported and fed
automatically. Liquid fuels are the best choice as propane or natural
gas are stored under pressure and are vented in case of over pressure
creating a danger of explosion. A Stanley, whose pilot had been
converted to use propane exploded when vented gas from a spare propane
tank carried under the passenger seat ignited killing the driver and
injuring the passengers. Possible liquid fuels are kerosene, fuel oil,
diesel fuel, and soybean distillate fuel. A properly designed burner
system could burn a variety of fuels by using an oxygen sensor in the
exhaust to control the proper fuel air mixture.
6. Steam cars of the past outperform I.C. cars.
Yes. - The Doble cars produced between 1923 and 1930 weighing over 4000
lb. could accelerate from 0 to 75 mph in under 5 seconds. and could
maintain a top speed of over 95 mph. The early Stanley's produced so
much torque that they lifted the front wheels off the ground when the
throttle was opened too quickly.
7. Steam cars are unreliable and require a lot of maintenance.
No. - A Doble E14 produced in 1923 was driven over 600,000 miles
requiring only normal maintenance. The Doble cars required no more
maintenance then their internal combustion counter parts. Other
Doble's are known to have traveled over 200,000 miles having only
routine oil and tire changes.
8. The Doble Steam Motor Company failed because of engineering design
problems.
No. - The company failed because of lack of funding. This is a sad
story for the steam car company that could have been. The lack of
funding was brought about by one Mr. Edwin M. Daugherty, the
Commissioner of Corporations in Los Angeles California. Mr. Edwin M.
Daugherty refused to issue the permit necessary for the sail of
additional stock until 50 cars had been produced and had given
satisfactory service in the hands of owners for six months. This was
all very peculiar as Mr. Edwin M. Daugherty had received the
independent report concerning the excellence of the car under test.
Also the Cooperate Securities Act designed to prevent fraud in the sail
of stock provided that if the Commissioner (Mr. Edwin M. Daugherty)
upon examination of the application finds, that the proposed plan of
business of the applicant is not unfair, unjust or inequitable, that it
intends to fairly and honestly transact business, that the Commissioner
(Mr. Edwin M. Daugherty) shall issue to the applicant a permit . It was
reported that Mr. Edwin M. Daugherty repeatedly stated that he did not
question the integrity of the officers of the company, and at one time
gave them a letter as follows: Pursuant to your inquiry regarding the
Doble Steam Motors Corporation, beg to advise that there is nothing in
our files or that has come to my attention, personally, which reflects
upon the integrity of the promoters of the Doble Steam Car or the
Company.
steam autos of the past
http://ghlin2.greenhills.net/~apatter/oldcars.html
.
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