"Doble's Steam Car, In the Heat of Invention
How the Steam Automobile Almost Displaced Gasoline Cars
By: John Shepler
Howard Hughes had a secret weapon. No, it wasn't an airplane. This was something he acquired long before Hughes Aircraft became famous. He was only 19 years old then, an obscure Houston teenager. But Howard had something fast, something few others had or could beat. It was a very special car. Extremely quite and surprisingly quick. With it, Howard Hughes out-raced all the rich young men of Houston. When he moved on to California, he left his Cadillac in Houston, but with him came his Doble Model E...an incredible steam car."
Most of the later steam cars ran on fuel oil / kerosene, since it was easier to use. The Doble car is said in the article to get "10 to 14 miles per gallon on fuel oil".
Admittedly we could do better today, and perhaps build vehicles based on fluidised bed coal heat, but replacing oil as a transport fuel is basically impossible (today) - which is why there's renewed interest in coal-to-liquid technology which leverages known coal reserves into a fuel compatable with a massive existing infrastructure.
Joined: Oct 04, 2004 Posts: 243 Location: the Village
Posted: Wed Oct 06, 2004 9:05 am Post subject: what the hell are you trying to do?
It doesn't say that at all, how come you think you can get away with such a blatant lie and quote something that doesn't exist, you're sick.
It does say this,
"By the time they incorporated these advances, the Doble steam car could travel 1,500 miles on 24 gallons of water. There was no steam visible in the air, and the car was ready to run in a minute and a half after starting. The almost silent Doble would accelerate from 0 to 60 in 15 seconds, remarkably fast at the time. In factory tests of the Model E chassis, one launched from 0 to 75 miles per hour in 10 seconds."
Joined: May 17, 2004 Posts: 1969 Location: Democratic People's Republic of Washington
Posted: Wed Oct 06, 2004 12:26 pm Post subject:
62.5 miles per gallon of water would be the figure for this car for this steam engine, which I will admit that is damn good, with automobile combustion engines now only nearing that figure. However, to quote from the article, "... and a flash kerosene heater activated by an electric switch on the dashboard." Since Kerosene it the fuel used to heat the water to generate steam, it still does not eliminate the problem of a fuel shortage for motor vehicles. Kerosene is derived from petroleum, as commonly used today as a fuel in jet engines, as well as common household heaters, (at least my home). One gallon of kerosene contains 131,890 BTUs, while gasoline contains 114,000 BTUs per gallon.
One BTU, (British Thermal Unit), is the amount of energy required to raise one pound of water by one degree Fahrenheit. Since one gallon of water weighs 8.33 pounds, it requires 8.33 BTUs to raise the temperature of one gallon of water by one degree Fahrenheit. Since this article indirectly implied that this vehicle had the capacity of 24 gallons of water, it would take 199.92 BTUs to raise the temperature of the water by one degree Fahrenheit. Assuming an initial water temperature of 70F, (which is about room temperature), it would be necessary to raise the temperature by 142 degrees Fahrenheit* to get to the point of boiling. For ease of calculation, I will assume that it will flash-boil, (transform directly into steam), and not lose heat after initial heating. Giving these factors, it would require 28,388.64 BTU's** to generate enough steam to power this vehicle. This would be equivalent to 0.21524482523314883615133823640913 gallons of kerosene, or 0.24902315789473684210526315789474 gallons of gasoline to power this vehicle 1500 miles. This would equate to 6,968.808650220651640938065366996 MPG for kerosene as a fuel, or 6,023.5361750333936391457991647541 MPG for gasoline as the fuel.
This would help the transportation problem, and would help reduce the peak oil problem now facing humanity, but keep in mind that for this to make a very large difference, the global fleet of roughly 700,000,000 combustion powered vehicles would need to be replaced with these steam powered vehicles. Considering the average length of a vehicles life, (about 20 years on average), it would take until roughly 2024 until all vehicles worldwide were replaced with these vehicles. By then, we as a globe will be very deep into the downside of Hubbert's peak, and this will only lessen the burden of an energy decrease, not eliminate it. It would have been much better if this was implemented during the early automotive history, and not delayed until now.
*=assuming the universal 212 degrees Fahrenheit boiling point of water at sea level with 101.325 kPa, (kilo-pascals, [one pascal is equivalent to one newton of force per square meter of area]) of pressure.
**=Assuming 100% efficiency _________________ Here Lies the United States Of America.
1500 (Miles) / 0.21524482523314883615133823640913 (gallons of kerosene)= 6968.808650220651640938065366996 MPG.
Referring to the efficiency, I was referring to for 100% efficiency in BTUs, it would be required to be in the exact same conditions as when the unit of measure was specified in the modern form. Any variations in atmospheric pressure, temperature, altitude, humidity, prevailing winds, etc would skew the actual amount of required BTU's necessary to power this vehicle. As a steam engine is only about 80-85% energy efficient, achieving 100% energy conversion would be impossible. Energy conversion of 100% is not possible under any circumstance due to the second law of thermodynamics, but it is possible to replicate a laboratory setting where units of measure were specified. _________________ Here Lies the United States Of America.
k_semler - perhaps the anomally lies partly in the BTU requirement, and maybe arises from the differences between British and US measures ?
1.0BTU (British Thermal Unit) = the ammount of heat needed to raise the temperature of 1.0 pound (British) by 1.0 degree farenheit. There are 10 pounds (British) of water in a gallon (British).
In addition, steam at 240 degrees F is little use for driving pistons. For this it has to be far hotter.
Its an old but none the less valid question: if steam propulsion would allow us to raise fuel efficiency 100-fold, why can I find no reputable research institute on the web that is researching it ?
You have made a major calculation error. The largest part of the energy in heating water to steam goes into the phase change, i.e. the latent heat of vapourisation. It takes approximately 1100 Btu/lb to convert water to saturated steam at the boiling point. Therefore it would take an additional 220,000 Btu to convert 24 gallons of water to steam. Assuming your other numbers are correct, total energy of water to steam = 250,000 Btu.
One small addition! There is an efficiency in getting heat from combustion of kerosene in to the water to produce steam. If this process is 80% efficient, then you actually need 1.9 gal/0.8 = 2.4 gal of kerosene.
VMA - Putting 631mpg as a 25-fold increase in energy efficiency, together with the utter lack of interest by Research Institutes, including those in Japan that lacks oil reserves, there is plainly some further factor we've yet to identify. Any ideas ?
Joined: Jul 18, 2004 Posts: 198 Location: S. Yorkshire, UK
Posted: Wed Oct 06, 2004 2:08 pm Post subject:
There are several problems with those numbers:
1) No mention is made of water recycling - much of the steam will condense into water and can then be reheated into more steam. You only need a tank to replace losses through seals, etc. Of course, the water you use has to be distilled, otherwise you will clog up your engine.
2) There is that no account is taken of the energy needed to actually boil the water in the first place. (k_semler ignores this energy, but calculates the energy needed to heat the water to boiling point. The reverse would be closer to being correct, as the energy needed for heating is dwarfed by the energy needed to actually boil the water - the latent heat of vaporisation).
3) There is no account of efficiency. All heat enegines are limited by the Carnot efficiency, which is a function of the maximum and minimum temperatures of the working gas or steam. The reason why gasoline/diesel engines can get such high efficiencies (approaching 40% for big diesels) is because of the immense temperatures achieved by the burning fuel/air mix. Unless you use high-temperature superheated steam, you will be limiting your efficiency to a terrible level. 29% is the theoretical limit for 150C steam and 25C coolant temperature. A more realistic coolant temperature in summer, will take you below 20%.
Joined: May 17, 2004 Posts: 1969 Location: Democratic People's Republic of Washington
Posted: Wed Oct 06, 2004 2:16 pm Post subject:
I would imagine that the difference between US and Imperial conversion rates probably did distort my figures some, as I assumed US measurements. Do you have a larger gallon, or a smaller pound? Over here, a pound is 16 oz, and a gallon is 128 oz. And as I said, the figures I gave were for a flash-boil where the water is converted directly into steam, (with no transient point); at an atmospheric pressure of 101.325 kPa, with the factor of 100% energy conversion, (which cannot under any circumstance happen--ever). I also assumed that 212 degree Fahrenheit steam would be sufficient for driving this engine. As I also said, these "perfect conditions" were put in place to ease the calculation process. Considering you factored in the actual variants, I will trust your final number at ~631 MPG. _________________ Here Lies the United States Of America.
Joined: Sep 26, 2004 Posts: 40 Location: Australia
Posted: Sun Oct 10, 2004 5:19 pm Post subject:
G'Day All,
The trouble with theory is that it is theoretical. Anyone interested in steam should take a good hard look at the work of Ted Pritchard from Brisbane, Australia.
I first saw Ted on TV in the late 60's and he is still pursuing steam - the fact that they can run on a variety of fuels makes them ideal in the Post Peak Times. Mileage is not very good -- http://www.pritchardpower.com/
But it would run on powdered macadamia or walnut shells!!
The name of the game should be conversions not wait until new manufacture. Just imagine how happy a grey haired gypsie would be if it did not cost anything to run the mobile home!!
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
News
Discussions
Resources
Members
Forum FAQ
Search
Usergroups
Profile
Log in to check your private messages
Log in
