tdmidget Stirling engines are a curiosity, nothing moree. The wikipedia article, which appears to be written by others in love with it , admits that is is "cost competitive" with the internal combustion engine up to 100 kw. That is 134 horse power, not exactly locomotive range. It is dramatically heavier and larger. In short it is everything a locomotive engine cannot be. Apparently it is everything that no engine should be or they would replaced the internal combustion engine long ago. There will not be a successful engine internal or external combustion , that does not involve a phase change for at least part of its charge. Even natural gas fueled combustion turbines change from gas to plasma in the flame area.
Stirling engines are a curiosity, nothing moree. The wikipedia article, which appears to be written by others in love with it , admits that is is "cost competitive" with the internal combustion engine up to 100 kw. That is 134 horse power, not exactly locomotive range. It is dramatically heavier and larger. In short it is everything a locomotive engine cannot be. Apparently it is everything that no engine should be or they would replaced the internal combustion engine long ago.
There will not be a successful engine internal or external combustion , that does not involve a phase change for at least part of its charge. Even natural gas fueled combustion turbines change from gas to plasma in the flame area.
I'm no fanatic of the stirling engine, I simply think that its characteristics make useful for rail use. My post was kinda biased but many of the things I stated were simply facts. Power to weight ratio could be better, but power to weight ratio isn't as important in a locomotive as it much larger than a car or airplane. Consider the Diesel engine has been limited by power to weight ratio in areas such as aviation but has found itself useful in rail use and stationary power generation. Just my take though
Railroad to Freedom
It cannot be "no emissions" if it involved the combustion of any of those fuels you described. When you burn those things there is a byproduct created.
Dave
Lackawanna Route of the Phoebe Snow
Stirling engine are a curiosity, nothing more. The wikipedia article, which appears to be written by others in love with it , admits that is is "cost competitive" with the internal combustion engine up to 100 kw. That is 134 horse power, not exactly locomotive range. It is dramatically heavier and larger. In short it is everything a locomotive engine cannot be. Apparently it is everything that no engine should be or they would replaced the internal combustion engine long ago.
Post edited by moderator
http://en.wikipedia.org/wiki/Stirling_engine
http://www.howstuffworks.com/stirling-engine.htm
I know I talked about it before but I think there should be serious consideration for using a Stirling engine in a locomotive. Why? Well stirling engines have shown effectively used as electric generators, so the stirling engine could be used as a way to create electricity for the electric drive system and motors. A stirling engine has no emissions and doesn't "breathe" like a traditional combustion engine does, this enable it to burn anything from toxic dead plants to petroleum to coal. Stirling engines create minimal noise making them effective for use in residential areas unlike gas turbines. Stirling engines are on of the most efficient form of combustion engines period. This is a big one they are simple low maintenance machines by comparison to other engines, so simple to the the point where you can cram one into something the size of a Toy. A stirling engine also gains efficiency at higher altitudes and colder temperatures which makes it ideal for going up those mountain grades. Power output is also constant, when moving goods at slow speed this is an ideal characteristic. Power to weight ratio isn't perfect but there have been stirling engines that have achieved the same power to weight ratio as internal combustion and also consider a locomotive is a large piece of equipment there is a lot more space for it. The issue of it taking a while to start up is minor because there are stirling engines that start in 20 seconds, plus consider a lot of time is spent inspecting and preparing a train for a journey.
As the Mythbusters went to considerable pains to prove, they couldn't develop a plausible scenario where an ordinary car in an ordinary accident would erupt in a flaming fireball. That's a Hollywood special effects myth.
I wouldn't say "NEVER":
http://charlotte.news14.com/content/top_stories/658309/driver-killed-in-fiery-overnight-crash-on-i-485--body-burned-beyond-recognition
CSSHEGEWISCH Thomas 9011: The main problem with steam powered buses, trucks, and cars is not so much how to make them run. The problem is what happens when they have a bad accident. This is one of the reasons the cars that ran off of hydrogen was never mass produced. If you have a serious accident you are basically going to be in the middle of a big explosion that is certain to kill you. Propane does slightly better in a accident but not much better. I have often thought about having a steam powered car. But the idea of having a boiler in the trunk of my car that would rupture and explode during a rear end collision made me think twice about it. Even a minor rupture would spray scalding steam on everyone in the car. It's a terrible way to die. So what happens when the fuel tank on your gasoline-fueled internal-combustion powered automobile springs a leak in a collision?
Thomas 9011: The main problem with steam powered buses, trucks, and cars is not so much how to make them run. The problem is what happens when they have a bad accident. This is one of the reasons the cars that ran off of hydrogen was never mass produced. If you have a serious accident you are basically going to be in the middle of a big explosion that is certain to kill you. Propane does slightly better in a accident but not much better. I have often thought about having a steam powered car. But the idea of having a boiler in the trunk of my car that would rupture and explode during a rear end collision made me think twice about it. Even a minor rupture would spray scalding steam on everyone in the car. It's a terrible way to die.
The main problem with steam powered buses, trucks, and cars is not so much how to make them run. The problem is what happens when they have a bad accident. This is one of the reasons the cars that ran off of hydrogen was never mass produced. If you have a serious accident you are basically going to be in the middle of a big explosion that is certain to kill you. Propane does slightly better in a accident but not much better.
I have often thought about having a steam powered car. But the idea of having a boiler in the trunk of my car that would rupture and explode during a rear end collision made me think twice about it. Even a minor rupture would spray scalding steam on everyone in the car. It's a terrible way to die.
So what happens when the fuel tank on your gasoline-fueled internal-combustion powered automobile springs a leak in a collision?
As the Mythbusters went to considerable pains to prove, they couldn't develop a plausible scenario where an ordinary car in an ordinary accident would erupt in a flaming fireball. That's a Hollywood special effects myth. (IIRC, they needed to arrange an explosive-incendiary somethingorother to finally get the car to become an inferno.)
The real hazard with a present-day steam powered car would probably be the possibility of breaking lines. The boiler itself would be a pretty tough object. Years ago I saw a grainy old movie of a Stanley Steamer crash. The boiler went bouncing away, spewing steam from a variety of places where lines and fittings had broken. It never exploded.
Some basic facts remain. Steam propulsion calls for more weight, more maintenance and has a slower response time than its internal-combustion counterparts. It also requires more skill, and more attention, on the part of the person in immediate control. This is true whether the machine is on rails, mounted in a floating object, rolling on rubber tires or flying through the air. Things would have to change drastically to get the bottom line to a point where it would be truly competitive.
Chuck
There are many reasons that hydrogen powered vehicles are currently impractical but the "Hindenburg effect" you mention is not one of them...Hydrogen fuel when ignited burns very rapidly in an upward direction (which is why a number of experimental hydrogen vehicle have had high mounted storage tanks)...Hydrogen doesn't produce a fireball in all directions like you describe and burns itself out very quickly...
As far as Propane fuel, it has a good safety record and powers a fair number of road vehicles in the U.S (ditto Natural Gas)...
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Thomas 9011 The main problem with steam powered buses, trucks, and cars is not so much how to make them run. The problem is what happens when they have a bad accident. This is one of the reasons the cars that ran off of hydrogen was never mass produced. If you have a serious accident you are basically going to be in the middle of a big explosion that is certain to kill you. Propane does slightly better in a accident but not much better. I have often thought about having a steam powered car. But the idea of having a boiler in the trunk of my car that would rupture and explode during a rear end collision made me think twice about it. Even a minor rupture would spray scalding steam on everyone in the car. It's a terrible way to die.
In terms of steam car, there was a GM exp. car in the early/mid 70's, built on a stretched Pontiac Grand Prix. It was operational with AC, But was two to three time heavier compared to a 455 V-8 model and the excitement wasn’t there. Can’t recall if it was documented in High Performance Pontiac or the Pontiac Oakland Club International newsletter. Amazing, in the story she still exist. But the single piston cylinder was frozen solid by rust from sitting so had to be pushed around when displayed. With the end of Pontiac, don’t know what happen to it. Can’t recall if she was propane, oil or alcohol fired.
A comment on gas turbine engines:
Aircraft gas turbines are subjct to damage from ingested birds, so all of them have armor rings around the thrust fans, compressors and turbines. When Sully's flight ingested a squadron of geese, all the broken parts either stayed inside the engine casing or departed through the exhaust duct. Not many of the latter - no reports of falling shrapnel in Da Bronx. That, at least, is one form of damage that a rail-based turbine is unlikely to suffer.
We tend to think of locomotives as large - but they are really a very tight fit for any kind of complex technology. A fixed power plant has room for gasifiers, high-efficiency pulverizers, exhaust scrubbers, etc, etc, etc. Just where do you put all of that in a carbody that will fit the loading gauge and not be excessively long?
As for the anti-nukers, they are quiet because no one has mentioned their favorite hate object lately. Let one speaker, whether technological or political, mention Yucca Mountain and they will be out in full song!
To Thomas 9011: Yes, I know spent nuclear fuel is shipped by train on a regular basis, but trust me, the anti-nuke crowd doesn't like that either. They're not howling about it right now because there's no alternative way to ship it. But in the future, who knows? They just might start up again.
By the way, all this talk about steam engines in cars reminds me that in the early 70's Bill Lear ( of LearJet fame) had an experimental steam car in the works. Even produced a pre-production model that worked pretty well, but unlike his jet, it never took off.
tdmidget 54light15, the turbine shown in the diagram was single stage, quite capable of producing more than enough power for a bus. Dave the condenser is not "reusing steam". The condenser is an essential part of the Rankine cycle and could not be set up like their diagram. The turbine needs to exhaust directly to the condenser to produce the vacuum on the exhaust side. There are turbines set up similarly but they lose substantial power due to low vacuum.
54light15, the turbine shown in the diagram was single stage, quite capable of producing more than enough power for a bus.
Dave the condenser is not "reusing steam". The condenser is an essential part of the Rankine cycle and could not be set up like their diagram. The turbine needs to exhaust directly to the condenser to produce the vacuum on the exhaust side. There are turbines set up similarly but they lose substantial power due to low vacuum.
tdmidget, I think we're talking about the same thing here: Rankine cycle = closed steam-water circuit, just as is found in most electricity-generating plants. I agree that the diagram could be better. But, I think it is trying to demonstrate the cycle we're both referring to.
Regards
Firelock76 As far as a nuclear powered train is concerned I think we can all put it out of our minds. Ain't gonna happen, no way, no how. Can you imagine the screams from the people who are anti-nuclear power plants when they hear "Coming soon to a railroad near you, the new GE U-235!" My eardrums are shattering just thinking about it! And to 54light15: Oh yeah, I've seen those shots of Jane Russell in "The Outlaw." Not bad, not bad a'tall, but a bit before my time, don't ya know. Jenny's a contemporary, a "Boomer" like me.
As far as a nuclear powered train is concerned I think we can all put it out of our minds. Ain't gonna happen, no way, no how. Can you imagine the screams from the people who are anti-nuclear power plants when they hear "Coming soon to a railroad near you, the new GE U-235!" My eardrums are shattering just thinking about it!
And to 54light15: Oh yeah, I've seen those shots of Jane Russell in "The Outlaw." Not bad, not bad a'tall, but a bit before my time, don't ya know. Jenny's a contemporary, a "Boomer" like me.
They ship spent fuel rods and nuclear waste on trains on a regular basis. Granted those cars are built to with stand just about every catastrophe you can think of including being struck by a locomotive going over 100 mph. There has never been a incident that I have been aware of in all the years they have been shipping nuclear waste by train.
Hi 54light! Jane Russell, Sophia Loren, ah yes, I see. Dark, sultry, and slightly dangerous. Now Jenny A was an absolutely beautiful girl, sweey faced, just the type you wouldn't be afraid to bring home to meet Mom and Dad. Just like the girl I married. However, SHE turned out to be dangerous herself, hence the reason I call her Lady Firestorm! Still married after 35 years I might add.
And I though I was the only one who remembered "Supercar"! "Satisfactory, MOST satisfactory!"
54light15 Nuclear trains? Jeez- didn't I see a "Supercar" episode about that around 50 years ago? Nuclear generated electricity is well and good but Switzerland has water-powered trains.
Nuclear trains? Jeez- didn't I see a "Supercar" episode about that around 50 years ago? Nuclear generated electricity is well and good but Switzerland has water-powered trains.
Yeah, I remember the same episode - the reactor vessel in the train looked like a scaled down Dresden unit 1 vessel laid horizontally. Don't remember seeing much in the way of shielding, so Dr Beaker must have picked up a lethal dose of radiation on his ride...
The Milwaukee, BA&P, GN and sundry Pacific Northwest trains were also water powered - BART is now a combination of water, geothermal, wind, gas, nuclear and what-not powered...
- Erik
I wonder if in this case "reusing" steam means that the device has a closed steam-water circuit. So, after exiting from the turbines the steam goes through a condenser where it is turned in to water just below boiling point, which is then fed back in to the boiler (already having some preheat) to start the cycle all over again. No steam is exhausted to atmosphere. I presume the heat recovered in the condenser is used to preheat the secondary-air for combustion.
So all round, a more efficient arrangement than your conventional steam locomotive. However, the South African Railways had their remarkable 4-8-4 class 25 condensing locomotives. These had extraordinarily long tenders with giant fans to condense the exhaust steam fed by a pipe from the cylinders. The condensed water was then ready for return to the boiler already preheated. As all of the exhaust steam was returned to the tender, there was none to be used for creating a draught in the smokebox. Hence, as steam left the cylinders, it powered small turbines which drove a fan in the smokebox that created the draught instead. A very successful design for running through the arid Karoo, except that the smokebox fan did suffer somewhat in its abrasive environment. I've never heard whether the condensing feature resulted in improved efficiency. Also, the condenser equipment was not used to pre-heat the combustion air (although I believe the class 26 "Red Devil" did have some form of combustion-air preheat, but no condensing).
Possibly what is meant by 'reusing" steam in the turbine is that as the pressure decreases, volume increases hence the use of steam progressing from small to larger turbine rotors and stators before the steam is directed to a condenser similar to marine and power-plant practice.
Firelock, Jane was before my time as well and so was the 1949 Sophia Loren but so what. (now you know the kind of women I like) My father did see her in person at the Chicago premier of "The Outlaw" in 1945 when he was in the U.S.A.A.F. and he said she was way more gorgeous to see in the flesh than on the screen. Nuclear trains? Jeez- didn't I see a "Supercar" episode about that around 50 years ago? Nuclear generated electricity is well and good but Switzerland has water-powered trains.
ontheBNSF A film showing the development of steam technology use in intercity transit buses. The results were similar efficiency to GM Diesel buses with much lower emissions. Three prototypes were produced. What I find even more interesting is that it required one to operate this, usually a steam engine requires someone to monitor boiler pressure. It was capable of being operated by a normal bus driver with no extra training. Anyways in a matter of months the developers of the project achieved what took the automotive industry years to achieve, essentially the researchers fixed the steam engine's flaws. The most interesting thing of all of this is that the steam is reused unlike older steam engines where the energy would be unused and not contribute to drawbar performance. A lot has changed in both the realm of internal and external combustion since the videos were made in the 70s but they are interesting none the less. Part 1 http://www.youtube.com/watch?v=blGTfgc0gpk Part 2 http://www.youtube.com/watch?v=ZbxZWThuYqo Some other modern steam implementations Steam ford falcon http://www.youtube.com/watch?v=LJq2Hc_mXFI Cyclone engine http://www.cyclonepower.com/
Not sure what you mean by "reusing steam". The whole looks pretty bogus when they call a turbine an "expander".
what about thorium http://energyfromthorium.com/
While the weight requirements for an aircraft reactor are more stringent than for a locomotive, both would have concerns for fuel cladding integrity when using direct heating of the air serving as the working fluid for the gas turbines. The shielding challenge for a nuclear locomotive is not weight, but getting an adequate neutron shield that will fit in the loading gauge.
Most critical aspect of collision proofing the reactor would be decay heat removal.
FWIW, the French generate more than 70% of their electric energy from nuclear and thus a alrge percentage of their rail traffic is nuclear powered.
- Erik ('78 MSNE UCB)
Modern steam? Gentleman, I give you the Tornado! LEDs for headlights and a cab (I've been in it) full of computer equipment. It's nice to put your feet up and dream but the Brits make it reality!
Jenny Agutter? Nice, but I would dream of the 1941 version of Jane Russell but that's just me!
The nuclear aircraft engines were shielded only enough to protect the cockpit crew. There was little danger from radiation at altitude. Even enough air will attenuate radiation. This would not be the case with a locomotive. Very heavy shielding would be required and to make it completely collision proof would be impossible.
CSSHEGEWISCH Nuclear power is just steam generation using a different type of heat source, a controlled nuclear reaction instead of coal, oil, natural gas, etc.
Nuclear power is just steam generation using a different type of heat source, a controlled nuclear reaction instead of coal, oil, natural gas, etc.
While that's true for central station generating plants and naval nuclear propulsion, there have been proposals for gas turbine cycle power plants (General Atomics HTGR-GT) along with nuclear gas turbines for aircraft nuclear propulsion. Then there were the nuclear rocket engines (NERVA) and nuclear ramjets (Project Pluto AKA Supersonic Low Altitude Missile).
The gas turbine would be my first choice for a nuclear locomotive as it would allow efficient operation with a high heat reject temperature - or even simpler using an open-cycle gas turbine IF the core could be as to not leak fission products or activated cladding into the airflow (same constraint as for aircraft nuclear propulsion). Economics and safety concerns make a nuclear locomotive extremely unlikely
P.S. Nuclear power generation on a small scale (under 1kW electric) is usually done with a radioisotope thermal generator.
P.P.S. Heinlein's 1940 short story, "Blowups Happen", describes a U-235 fueled nuclear plant using a mercury topping cycle in combination with a steam cycle - it's amazing what he got right and what he got wrong was fairly subtle (though crucial).
As far as the price of coal, if railroads returned to steam locomotion, this would greatly increase the demand for coal and consequently drive up the price. Also to be considered is the cost and energy involved in maintaining the supply chain (much of which no longer exists) for a solid fuel. Also to be considered are the various EPA regulations concerning the burning of coal, PRB coal may be relatively clean but other sources are much less so. Also, fitting scrubbers to steam locomotives may be impossible.
For a variety of reasons, a return to steam locomotions just isn't going to happen and wishing won't make it so.
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