Steam Hybrid Car from BMW 663
RMX writes "BMW is unveiling its turbosteamer hybrid engine, which uses the excess heat in the exhaust system and reclaims 80% of it by powering a steam engine that assists the gas engine. Overall, this gives a 15% more efficient engine; and significant additional performance (power and torque) with practically no downside. "This project resolves the apparent contradiction between consumption and emission reductions on one hand, and performance and agility on the other," commented Professor Burkhard Göschel. Are steam engines the future of environmental-friendly hybrid vehicles?"
Downsite? (Score:5, Insightful)
Additional moving parts, and servicability? How many modern garages know how to service a steam engine?
Re:Downsite? (Score:5, Funny)
Just kidding, of course. It's probably a closed system, but the headline of this story certainly produces some amusing mental images.
Re:Downsite? (Score:2, Funny)
but i'd rather have a steam engined harley davidson, imagine that woosh-woosh sound when you leave the central square of the city
that 'woosh woosh' also makes you remember your deadlines at work which just wooshed by
Re:Downsite? (Score:5, Funny)
Unfortunately there's no way to make a steam engine loud enough to satisfy the average Harley owner. Too bad, since they're already accustomed to steam-engine performance.
Re:Downsite? (Score:2, Insightful)
Re:Downsite? (Score:2)
Re:Downsite? (Score:2, Informative)
To
Re:Downsite? (Score:5, Informative)
This is why Saab developed this [popularmechanics.com].
Re:Downsite? (Score:5, Interesting)
It is interesting to note that Volkswagen has come up with a new engine that is just 1.4 liters, yet it utilizes a supercharger and a turbocharger. The supercharger supplies boost until the turbo spools up, then an electro magnetic clutch disengages the supercharger. It peaks at 170 hp with a fuel consumption of 47.9 mpg.
Twin Charger [vwvortex.com]
Re:Downsite? (Score:2)
Perhaps there will be a steam-electric-fuel hybrid (tribrid?) at some point...
Re:Downsite? (Score:3, Interesting)
I sa
Re:Downsite? (Score:3, Informative)
Re:Downsite? (Score:5, Funny)
We'll go straight to Quadbrids. Steam/Electric/Fuel/Gravity (for when the other three, through a loose screw somewhere, interact themselves into a tangled mess). You can use the fourth drive method to coax it home. Wait, maybe it's a Pentabrid. Add the Biomechanical drive to push it home.
Re:Downsite? (Score:3, Informative)
A supercharger need to be "always on" any more than the driving wheels are "always on". It it was attached using a centrifugal clutch it would only operate above a certain RPM...
Re:Downsite? (Score:3, Informative)
I can't imagine a reason why a turbocharger couldn't be used at the same time as an exhaust-heat-powered steam engine. The steam engine uses the heat from the exhaust to drive the car (efficiency + performance gain), while the turbocharger uses kinetic energy from the ex
Re:Downsite? (Score:4, Informative)
because the heat is kinetic energy. if you transfer the heat to a steam system, you're slowing down the exhaust molecules. if you take the kinetic energy to run a turbine in a turbocharger, you're cooling down the molecules. you only have so much energy to work with. one set of numbers i do know: turbodiesel pickup truck towing a 12,000lb trailer up a hill. exhaust temperature before the turbo: 1200F. exhaust temperature after the turbo: 900F. the energy turning the turbine cooled the exhaust by about 400F.
one thing that i don't think has been mentioned yet, is that cool gasses resist flow more than hot ones. the cooler exhaust gasses will create more backpressure (==work for the engine) in the exhaust, just like adding a turbo - so that's one downside. over all, i think the turbosteamer is kinda neat though.
Re:Downsite? (Score:3, Informative)
Re:Downsite? (Score:2, Interesting)
The article doesn't state whether it would be necessary to periodically stop and fill up with water, whether it will be a closed system, and if not, will the water supply last as long as the fuel in the tank?
They mention extracting energy from the cooling water as an additional source of energy. But is this related to the water being used in the steam engine?
This article is very thin on specifics, but constantly having to stop and fill up with water sound
Re:Downsite? (Score:5, Informative)
Heat plant in the car [spiegel.de]. It uses a high temperature (up to 550 Celsius) circuit using water and a low temperature one using ethanol (alcohol) (operating at 150 Celsius). Both are closed systems.
Repairs... (Score:5, Insightful)
How many modern garages know how to service a steam engine?
I would think that BMW dealerships would be able to service BMW autos, no? Yes, I understand the rush to FP, but do you think maybe they'll have this covered by the time they go into production?
I am glad to see some innovation to the standard IC engine.
But I guess it's just easier to sit in your armchair and criticize real engineering...
Re:Repairs... (Score:5, Insightful)
Sure, the dealership will know how to service it, but that wasn't what I was referring to by "garages". I was referring to those independent garages where you can often get cheaper, better service. I don't take my 1991 Plymouth Voyager to a Chrysler dealership; They're booked solid and will want to replace half the car. I take it to a small guy on the outskirts of the city who comes up with cheaper solutions .
Oh, and fooey on FP. I really don't give a damn; it just happens more often because I'm a subscriber.
Re:Repairs... (Score:4, Funny)
sorry couldn't resist.
Re:Repairs... (Score:5, Insightful)
Re:Repairs... (Score:3, Interesting)
I live in Detroit. And yes, I see a ton of hybrids too.
If that's not a clue that hybrids are here to stay, I don't know what is.
BTW-- a good business plan would seem to go like this:
1. Start/buy a garage.
2. Wait for hybrids to come out of warranty
3. In the meantime, train your mechanics on hybrid technology
4. Be one of the first garages in your area to service hybrids
5. ???
6. Profit!
Re:Repairs... (Score:3, Funny)
Before electrical probs forced me to park it, I could spank nearly everyone in the land barge... er, '79 Cadillac Coupe DeVille. That big-ass car has a big-ass 7L V8 under the hood. You're forced to drive the damn thing like a grampa. Otherwise you just sit at the green light spinning the wheels. I ended up putting most of my tools in the trunk, just to add traction.
Seriously, it's not di
Re:Repairs... (Score:3, Interesting)
A while back one of the museums that I visited had a steam engine that was about 200 years old (hope I remember that right :-)). What I got out of the demo was:
1) It is fairly simple, construction is simplier than an ICE (internal combustion engine). Someone who knows how to service an ICE can learn to service steam quickly. Of course the question is how easy is it for the mechanic to master the interface between the two engines.
2) Steam engines are very reliable and last a loooong time. I
Re:Repairs... (Score:2)
Re:Downsite? (Score:3, Interesting)
The nice thing about a steam hybrid is that you don't have any high-voltage electrical cables running through the car -- so after an accident, firemen and police won't need to worry about getting electrocuted when cutting you out of your car.
Re:Downsite? (Score:2)
Re:Downsite? (Score:4, Interesting)
Most efficient car available is the Honda Insight M5, getting 83.1MPG and having the lowest CO2 emmisions of any car (80g/km, which is about 25% lower than the next contender). Unfortunately they're damned near impossible to get - the best quote I've found is £62,000 and no honda dealer I've talked to has even heard of it...
Next you've got a bunch of diesels (Citroen C2 1.4HDi at 68.9mpg & 108g/km), the Prius is quite a way down the list at 13th (65.7mpg but with lower co2 emissions).
The most efficient petrol engine available (Peugot 107) is only 61.3mpg... I'd like to see the figures for this BMW to see if it can beat that.
(source: http://www.vcacarfueldata.org.uk/ [vcacarfueldata.org.uk])
Comment removed (Score:4, Informative)
Real world value ... (Score:5, Insightful)
Re:Real world value ... (Score:4, Insightful)
New every 2 isn't such a problem... (Score:5, Insightful)
The trouble is when people buy new cars that are NOT environmentally friendly, those cars also continue to guzzle for as long as they're on the road. If the average vehicle coming off the assembly line were more efficient, then we'd be pushing out the older crap with newer, better stuff. But the average fuel economy of ALL manufactured vehicles has actually DROPPED since the 1990s: from Automobile and Light Truck Fuel Economy [policyalmanac.org]
An assumption (Score:4, Informative)
You're assuming the new owner doesn't have to drop a few k on new batteries. If a used car is going to take many thousands to make right, how well will it do in the used market?
From that standpoint this new "Snobby Steamer" is better as there are not lots of nasty batteries that eventually wear out.
Re:Real world value ... (Score:2)
The only way that you can live in the US and not drive is to live in a city center where you have access to public transit or can walk to work and shopping. That isn't going to happen until it becomes too expensive to live in the suburbs, and that isn't going to happen in the near future.
Re:Real world value ... (Score:3, Interesting)
Re:Real world value ... (Score:3, Insightful)
i'm sorry, but this is either troll or
if everybody in the world would be scrapping car after two years, we would be in seriously deep shit.
here, in "eastern europe" - ex-ussr, most cars are > 10 years old, some are > 20. they run relatively ok (though some lack stuff like air conditioning etc), are very cheap to maintain (they are simple and fixing them is easy). gasoline
Re:Real world value ... (Score:3, Insightful)
Compared to what, your fe
Re:Real world value ... (Score:5, Interesting)
And how much effort goes into raising obscure questions nobody is likely to have the answer for?
But in this case, intution with a little math can be a reasonable guide. Most people have no idea of the fabulous amount of energy the expend by driving around. A gallon of gasoline contains about 131 megajoules of energy, or roughly 124000 BTUs.
To melt steel, according to Google, is 377 kWh/mt. Since a kWh is about 3.6Mjoules or 3413 BTU. So, a single gallon of gasoline has enough energy, in a modern electric furnace, to melt over thirty six metric tons of steel in a modern electric furnace.
Now granted, we have to include the energy of the entire process, including mining transportation, and so forth. Supposing the cost of melting the steel is 1% of the total energy costs in creating the extra components. In that case a gallon of gasoline is sufficient to produce not 36000 kg of steel component, but 360 kg. Let's generously guestimate that is approximately the weight of a single unit.
Suppose with the added weight the net gain in efficiency is not 15%, but say 1.5%. Thus a car getting 25mpg now gets 25.25 mpg. Suppose the user drives the car 15,000 miles per year. In that time on the pre-unit version he uses 600 gallons. On the post unit vehicle, he uses 594 gallons, for a savings of six gallons.
Under these highly pessimistic assumptions, the energy for creating the unit is paid back in two months.
However, I doubt the unit weighs nearly 800 lbs; nor that a 15% increase in powerplant efficiency with modest weight addition would result in only 1.5% increase in vehicle efficiency. Note that the article is claiming that the net efficiency of the car increases by 15%. It's not inconceivable that the manufacturing energy could be recouped in a single fill up.
Americans for some reason have a weird bias against efficiency; I always hear these kinds of objections when an idea to make something more energy efficient comes up. It's almost like we're afraid of it.
Re:Real world value ... (Score:3, Insightful)
Sorry to jump in anonymously here but that is an interesting point, and one that is relevant to most developed countries, including here in England.
My theory is:
The whole point of 'modern' living, is to reach a state where we have so many machines and resources available to each of us, that we neve
Re:Real world value ... (Score:4, Insightful)
I know exactly what you are talking about. I have spent a lot of time arguing energy technology and efficiency on peak oil message boards and it kind of goes like this:
Unabomber: Oh goody, peak oil is going to happen we're all going back to live on subsistance farms and industrial society and all those idiots with SUVs will be punished!
Me: Hey, but what about technology X?
Unabomber: Look at the EROEI (Energy Returned on Energy Invested). To get all the steel out of the ground to build that would cause huge amounts of global warming.
Me: Ok, but it's something right? It will make life better right and the investment will eventually pay off?
Unabomber: Ha Ha! Nothing can stop the doom of technological society. Your puny inventions are no use!
Me: But I kinda like technological society.
Unabomber: Nature must punish you for your hubris to rise above the other animals. Repent and move back to an organic farm while there is still time!!!
Me: Well I'm going to ignore you and build technology X anyway.
Unabomber: But you'll cause global warming and keep perpetuating your unsustainable way of life.
Me: Better than going back to the stone age.
BMW an innovator in alternative fuels (Score:5, Informative)
Current fuels will eventually go the way of the steam engine, or wait, maybe not the steam.
Interesting site: http://www.bmwworld.com/hydrogen/ [bmwworld.com]
Re:BMW an innovator in alternative fuels (Score:3, Informative)
The only way I know how to get pure hydrogen around here right now is to put magnesium into vinegar (or any other acid
Tiny little difference (Score:2)
Hydrogen is not yet mature while petrol and steam engines are.
You Hydrogen People (Score:3, Interesting)
The only thing hydrogen is good for is to reduce emissions from the vehicles themselves, but you only end up pushing the polluti
Re:You Hydrogen People (Score:4, Insightful)
And which are signifcantly more efficient than masses of cars spewing less refined emissions, especially nuclear plants.
Essentially your post says "punish auto owners, and reward mass transit users" while completely ignoring the fact that mass transit is impractical in many places and always will be.
Re:You Hydrogen People (Score:5, Informative)
> vehicles themselves, but you only end up pushing the pollution to
> power generating stations, which we'll need a lot more of if the
> 'hydrogen economy' takes off.
Except that you're missing a critical piece here: since hydrogen extraction facilities are very large and stationary (something most cars are not), they can use fuels that would simply not be an option for the cars themselves, such as wind, solar, wave or nuclear power. And even if you do keep producing hydrogen by burning fossil fuels, because of the size and relatively low number of production facilities you have the economic luxury of investing in technologies that burn fossil fuels more efficiently and transform waste into more benign forms than would be feasible in the cars themselves.
turbosteamer eh? (Score:3, Funny)
BMW Philosophy. (Score:5, Funny)
"A reduction in consumption amounting to a few percentage points over the entire model range exerts higher overall effects on the general population than high percentage points for a niche model."
Now the company just has to make BMWs available to the "general population"!
VW has a pretty amazing protype as well (Score:3, Interesting)
http://www.canadiandriver.com/articles/gw/vw1litr
Pretty amazing .
A model made with less expensive materials would still exceed 100 mpg .
Ex-MislTech
Heat Recovery Steam Generator? (Score:3, Insightful)
Downsides - A few (Score:4, Insightful)
* More parts == higher maintenance (pumps, special catalytic convertor, etc)
*at least 24 ft of piping that may be impacted by even minor collisions
*Steam systems extra sensitive to corrosion from impurities in coolant.
Where's the Condenser? (Score:4, Interesting)
Re:Where's the Condenser? (Score:5, Informative)
Hey Stan... (Score:4, Funny)
It hardly reclaims 80% of the energy (Score:3, Interesting)
There's a much simpler and more effective solution... Go full electric drive hybrid. Decouple the engine from the drive.
Re:It hardly reclaims 80% of the energy (Score:2, Informative)
Re:It hardly reclaims 80% of the energy (Score:4, Insightful)
There's a much simpler and more effective solution... Go full electric drive hybrid. Decouple the engine from the drive.
So you want to go from:
gasoline->motion->electricty->motion
instead of
gasoline->motion
I can't really imagine that's any more (and probbably less with all those energy form transformations) efficient than the current hybrids. Engine efficiency comes from small engines running at constant speeds. That's already accomplished with the hybrids.
Re:It hardly reclaims 80% of the energy (Score:4, Insightful)
Electical motors, on the other hand, are linear: turn up the juice, and the thing turns faster.
The philosophy of using a diesel with electric drive is to keep the diesel engine turning at exactly the right RPMs to maximize efficiency, supplying power to the electrical drive as needed. This way, the locomotive gets the same efficiency moving slowly as it does at speed (as opposed to cars, which would really rather be in 5th gear going 80 km/h).
Re:It hardly reclaims 80% of the energy (Score:3, Insightful)
The advantage of the fully decoupled engine is that it is at the same efficiency all the time, and around town that's a win.
Justin.
Re:It hardly reclaims 80% of the energy (Score:4, Insightful)
Consider a redesign of the combustion engine that has just cylinders that use 2 a modified 2 stroke compression cycle on each end, and just move the cylinder in a tube that has an electric coil. Put a magnet in the middle and you can transmit power without needing to connect the cylinder to any mechanical transfer system. It'll produce a pretty standard AC sine-wave, and because there's no direct mechanical coupling it can run at optimal efficiency or power rates instead of having to deal with constant acceleration/deceleration. You could even shut down and power up individual cylinders on demand, and since there's no mechanical connections, using say, dozens or hundreds of smaller cylinders for better efficiency and more flexible power would be possible.
On the electric side, motors have far better low end torque, and less moving parts overall. If you did the design right you might even be able to eliminate the mechanical transmission for different gears completely. Not having mechanical transfer means you can easily do things like 1 motor per wheel directly coupled. This would again provide more robust redundancy, better efficiency, scalability (only run 2 motors when needed i.e. highway driving), better driving properties (full time all-wheel drive), etc.
Granted you're still going gas->motion->electricity->motion, but you're not replacing just gas->motion. You're replacing gas->several thousand moving parts with friction losses and failure rates->motion with gas->electricity->maybe a couple dozen parts->motion. The removal of the complex mechanical transfer system is where you'll get the efficiency AND reliability boost. But that would make cars last for 20 years, and nobody wants that, right?
Re:It hardly reclaims 80% of the energy (Score:4, Interesting)
I realize why none of the current hybrids do this - their whole selling position is that the public API is just like the current gasoline vehicles - but having the option makes a lot of sense. This means that its cheaper to "fuel" the batteries at home during the night, and cleaner too thanks to more efficient power plants, but you can treat it just like a regular car for a cross-country trip. Not a bad idea. Currently the conversion is expensive, ~$5K, but that's mainly because its a complex, low-volume retrofit.
Steam engine options (Score:5, Funny)
It certainly would get the attention of the person in front of you preening themselves in their rearview mirror!
Thermo? Weight? (Score:2, Interesting)
I'm holding out... (Score:4, Funny)
Next Thing They'll Invent... (Score:5, Funny)
The obvious next step (Score:3, Funny)
Chiti Chiti BMWang BMWang (Score:2)
Band-aid upon a larger problem (Score:2)
Solutions like this still have a few problems though. a) still using gas. b) short term solution. What happens when we run out of gas? c) much more complex and more moving parts. It could be argued that an engine that uses these technologies
Re:Band-aid upon a larger problem (Score:3, Interesting)
No. All a turbo allows you to do is burn the fuel in the engine more rapidly. You get more power, but at an increase of fuel economy. This solution is making use of the currently wasted byproduct of internal combustion; i.e heat to get more power from the same amount of fuel.
Well, it depends on how you use the turbine. As the exhaust gasses expand through the turbine they cool down. Having a steam engine is just another way of extracting part of the heat that goes out the tailpipe.
So, usually with a turboch
Could be combined with conventional hybrid... (Score:5, Interesting)
I'm a bit skeptical that really make this practical, but it's an impressive idea; a combined cycle automobile-sized piston engine.
Re:Could be combined with conventional hybrid... (Score:3, Interesting)
Re:Could be combined with conventional hybrid... (Score:3, Interesting)
I drive a civic hybrid in Arizona and we have lots of mountains to drive through. Many times I run the batteries completely down while climbing mountains and then I am stuck with the 95hps of the gass motor and none of the 15hps of the electric. While the engine just runs faster and I can still cli
Steam with Fuel Cells (Score:3, Interesting)
Re:Steam with Fuel Cells (Score:2)
I have no idea how much waste heat most fuel cells generate once they're at their operating temperature. You'd want to be very careful about how much heat you skim off the top to run a steam engine.
My Beamer is a Steamer (Score:3, Insightful)
Re:My Beamer is a Steamer (Score:3, Interesting)
A used vehicle for $11500 hardly puts things in the realm of "super rich".
Even if you compare prices for new vehicles, the perception of BMW as a "rich man's car" is odd. A new 3-series (which, I know from experience, *can* fit 5 rather rotund adults comfortably) can be had f
Re:My Beamer is a Steamer (Score:3, Insightful)
Honda Pilot 18/24 (city/highway) (2wd)
Toyota Highlander 18/24 (city/highway) (4wd)
Ford Explorer 15/10 (city/highway) (4wd)
Now granted the real mileage of a lead foot driver will be lower, and these aren't necessarily the absolute maxed out versions of these vehicles (biggest engine, heaviest load), but I'd say that you're the one who's full of shit.
Certainly the biggest SUV, with biggest engine, pulling its maximum rated towing lo
Misconceptions. But this is a GOOD thing. (Score:3, Insightful)
Of course at this point this is just a concept system, it remains to see if it ever makes it into production.
My hope would be to see the steam engine addition connect to an electrical hybrid system, and that the main power source be a low-rev/high torque diesel engine. Do that with dynamic braking, etc. and you might just get an automobile engine that is say, 70% as efficient as the big diesel locomotive engines have been for what, 30 years?
Mr. Burns at a BMW Dealership (Score:3, Funny)
Why it's a ....... Beamer Steamer (Score:3, Funny)
Been done before: Stanley Steamer, c. 1906 (Score:4, Interesting)
There had been previous steam-powered cars -- at least three decades before Stanley -- but they seemed to be taking off at right around the same time people like Benz (in Germany) and Daimler (in France) were coming out with gas internal combustion models.
As far as the tradeoffs, Stanley's assessment is described this way by About.com:
No, this is a Combined Cycle (Score:5, Interesting)
Curtis-Wright did something similar with the turbo-compound engines, where exhaust turbines were coupled to the crankshaft - got about 20% more power for a given fuel consumption - and allowed the DC-7C and L-1649's to go from New York to London/Paris nonstop.
Minimizing energy loss is good (Score:4, Interesting)
Heat in the form of engine exhaust, and in the form of friction braking are two major areas of energy loss for a vehicle as well, but only recently has capturing this lost energy been a potentially desirable goal.
This BMW heat capture system seems like a great idea. Ford also has a regenerative braking system called Hydraulic Launch Assist [designnews.com] which could capture much of the energy lost in braking as well. Electrics and hybrids already reclaim some of this energy by using it to generate electricity to charge the storage batteries.
It will be interesting to see if the ultra efficient cars of the future use any or all of these technologies.
The idea is old (Score:4, Informative)
35+ years go we did a paper exercise in a thermodynamics class to evaluate the potential efficincy of a Rankine cycle (steam) engine running off waste heat from an internal combustion engine. IIRC, we got efficency numbers about like what BMW is claiming.
One weakness is that the systems aren't very efficent at low power, such as stop and go traffic or slow driving. There just isn't enough waste heat in the cooling system to do anything useful until you start making a reasonable amount of horsepower.
Some ships and stationary power plant use steam engines (usually steam turbines) that run off waste heat from gas turbine engines to boost efficency. Celebrity's Millenium Class cruise ships are one example.
I've been waiting for this (Score:3, Informative)
Re:I've been waiting for this (Score:4, Informative)
Re:Choo choo (Score:2)
Re:Choo choo (Score:2)
Re:Choo choo (Score:2)
What I'm waiting for... (Score:2)
Re:Choo choo (Score:3, Interesting)
The (only) difference between (1) internal and (2) external combustion is that the fuel energy is used to create an expansion due to (1) a chemical reaction and (2) a state change in some other material. The expansion is then used to drive a piston and after that it's all gears!
The biggest problem with internal combustion is that the heat of the reaction can't be avoided and is absolutely not wanted,
Re:Choo choo (Score:5, Informative)
Oh yes it does! Just try putting diesel fuel into your Otto Cycle automobile!
The Diesel Cycle is inherently different from the Otto Cycle in that there are no sparkplugs. As opposed to an external ignition source, diesel engines use nothing but the compression in the cylinder to ignite the air-fuel mixture. Overgenerallizing a little, diesel engines operate entirely on what you would call "knock."
I could go on about temperature vs. entropy comparisons between the Diesel and Otto cycles, but your eyes would glaze over.
For the same compression ratio, the Otto Cycle is more efficient than the Diesel Cycle. However, when engineering comes into play, you can have much, much greater compression ratios with a Diesel engine than an Otto engine. The source of ignition in a Diesel Engine is the pressure in the cylinder, and the pressure is uniform throughout the chamber, ensuring uniform combustion and uniform expansion of the cylinder. You can get away with building cylinders, say, 1 m in diameter. With the Otto Cycle, because you need an ignition source (sparkplugs), combustion in the chamber will be non-uniform and there will be more energy lost because of it, so F-1 and GPX cars use many, many cylinders that are very long but very slender. Only a fool would use an Otto Cycle engine to power a locomotive, let alone a ship.
"So... there's no reason you couldn't make a highly efficient diesel external combustion (probably steam) engine."
No. Diesel means internal combustion. If you want external combustion, you build a steam turbine (far fewer moving parts), and they don't care what you burn. There's no reason to burn something as expensive as refined diesel fuel. Modern steamships burn whatever it is the refineries can't sell to anybody else.
You could try a gas turbine, but, again, diesel fuel isn't designed for that; it will ignite when you don't want it to, and not ignite when you need it to. Go with kerosene.
"So... there's no reason you couldn't make a highly efficient diesel external combustion (probably steam) engine."
Not a mechanical engineer, are we?
"If the water runs out,"
Then you take it back to the dealer. The water isn't supposed to come out, you put your superheated steam through the preheater, getting it back down to saturation before you put it back into the boiler again. You should no less run out of water than you would run out of motor oil or transmission fluid (with similar Very Bad Things happening to your engine if you do).
Re:Choo choo (Score:3, Informative)
Apparently you are right [bath.ac.uk].
(What I want to know is, what do they use as a starter and a fuel pump for this thing?)
Re:Choo choo (Score:4, Informative)
Umm no a Diesel engine it a specific type of engine the correct name is a Diesel cycle engine. It was invented by a man named Rudolf Diesel and uses extermly high compression to ignite an air fuel mixture. The typical car engine is also called an Otto cycle engine after it's inventor.
While by definition any fuel you put into a Diesel engine is Diesel fuel Diesel engines can burn a many differn't types of fuel. Everything from heating oil to jet fuel will work in a diesel cycle engine.
"The biggest problem with internal combustion is that the heat of the reaction can't be avoided and is absolutely not wanted, so you have to carry around cooling systems. For external combustion the heat is exactly what you want, and it's pretty easy to obtain
Again no. The heat is what makes an internal engine work. It is a good thing. You only have to cool an engine because of the limits of the material. The hotter a Diesel gets the better it will work up to the point the lubrication or the material fails. BTW External combustion systems have EXACTLY the same limitations on max temp. A steam turbine is limited by how much heat the material and lubrication system can take before failure. You will still have to a cooling system for a steam engine and limit the temperature of the turbine.
An Otto cycle engine has issues with detonation so there is also a chemical limitation on max temp.
" The downside is you have to carry around some other material (for the state change) which is typically voided rather than cooled and re-used."
Not all external combustion engines use a state change. The Stirling cycle engine for example.
Some of the most efficient prime movers on Earth are massive Diesel cycle engines used in shipping and at power plants.
Re:Choo choo (Score:3, Interesting)
I realise that the US is a different world, but there are parts of Europe where about fifty percent of cars sold are diesel (France) and it's getting on for that here in the UK. My last three have been diesels. They're exactly the same as the equivalent petrol car, except the red line is a bit lower, you can roll onto the power from 1500rpm and they're slightly harder to get as autos. My current car has the awesome VW DSG twin-
Re:Yeah, but how do diesels start in the bitter co (Score:3, Informative)
Re:Don't you just love /. engineers (Score:3, Insightful)
I beg to differ. Do you own a recent vintage BMW? I'm talking about electrical gremilins that will make you pull your hair out. Don't even get me started on VW - disintegrating interior trim, broken window regulators, failing inginition packs. . . etc. etc. Even Mercedes is having a
Volkswagen quality is horrible (Score:3, Interesting)
Speaking as a man who used to own a 1995 VW Golf, I have to take issue with you on this.
Germans made a car that in theory was reliable and well-built and efficient. In fact it was continually breaking down, costly to fix, had exterior parts falling off every summer when the adhesive softened, and rarely got more than 25 miles to the gallon out of a gutless 2