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Steam Hybrid Car from BMW
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?"
...with practically no downside.
Additional moving parts, and servicability? How many modern garages know how to service a steam engine?
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Although the idea seems nice on the surface, how much more energy goes into refining the metal for the additional engine? How much weight is added? How much cost is added? Although many of these schemes seem beneficial, when evaluated over the lifespan of the product it may be a net zero or net loss from the existing technology. If people would stop buying new cars every two years, we would be better off than everyone buying the newest, latest greatest enviro-trendmobile constantly.
BMW has the ability to make Hydrogen-powered production cars, it is a shame that they have not caught on yet.
Current fuels will eventually go the way of the steam engine, or wait, maybe not the steam.
Interesting site: http://www.bmwworld.com/hydrogen/
He who knows best knows how little he knows. - Thomas Jefferson
Let's just hope this isn't comming from their Cleveland factory.
Quote from the company's press release about BMW's philosophy towards efficiency:
"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"!
If I clone myself, can I call it a thread?
If a girl winks to us, can I call it a race condition?
Combined cycle power plants aren't exactly revolutionary. They're more efficient, but more expensive to buy and maintain.
Here are a few downsides off hand:
* 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.
"God fights on the side with the best artillery." - Napoleon, Marshal of France - speaking truth to power
Steam engines need to carry lots of water or provide a large cooler/radiator to condense the exhaust steam back to water for recycling. Bill Lear's plan to put "modern" steam engines into trucks and busses failed because he couldn't solve this problem. The article doesn't address this issue.
...I thought that idea ran out of steam decades ago...ba-da-boom!
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
I wonder if they will offer a steam whistle as an option to replace the car's horn.
It certainly would get the attention of the person in front of you preening themselves in their rearview mirror!
If "disco" means "I learn" in Latin, does "discothèque" mean "I learn technology"?
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...
A house divided against itself cannot stand.
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
...for a Mr. Fusion Home Energy Reactor add-on for my Delor..er...Nissan.
How you see the world is how the world sees you.
... a network of metal tracks to operate them on.
Anybody want a peanut?
I'm a bit skeptical that really make this practical, but it's an impressive idea; a combined cycle automobile-sized piston engine.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
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.
AccountKiller
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?
...Open Source isn't the only answer -- but it's almost always a better value than the alternatives...
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:
"Fundamentalism" isn't about divine morality. It's about human authority.
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 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 only thing hydrogen is good for is to reduce emissions from the 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."
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.
How pathetic are you that you follow me from topic to topic and waste all your mod points at once modding me down?
There are some interesting people out there doing Prius conversions - my in-laws are looking at one. Basically they increase the battery capacity (using more efficient parts, IIRC, so it doesn't significantly increase the weight, but this is 2nd hand) and install a house charger. The new cars get ~200 miles on a full "charge" but, unlike traditional plug-in electrics, the motor is there for when you want to go further without plugging in.
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.
You're special forces then? That's great! I just love your olympics!
" I think you are confusing fuel and engine form. Diesel is just a fuel, it doesn't dictate the engine type."
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).
" I think you are confusing fuel and engine form. Diesel is just a fuel, it doesn't dictate the engine type."
;-)."
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.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
> The only thing hydrogen is good for is to reduce emissions from the
> 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.
The power curve put out by an internal combustion engine isn't linear; it prefers to stay at a particular range of RPMs for maximum efficiency. This is why cars have transmisisons to change gears, trying to keep the engine at that preferred RPM range no matter what RPM the wheels are turning at.
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).
This idea isnt new, doing it in a potentially production car is.
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.
>To complex? Compared to what? This is a BMW not some american car. Germans may suck as human beings >but they know how to make cars. Cars that actually just bloody work instead of needing to be fixed >every ten miles.
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 hard time with reliability issues these days.
Germans do make cars that are a hoot to drive, but they sure as hell aren't as reliable as you think.
You can't take heat from the catalytic converter because that heat is required to catalyze the gasses. That's why emissions suck for the first 5 or so minutes that you run your car - the catalyst is cold and not doing its job. That's also why urban areas use MTBE and other oxygenates in fuel in the winter time - so that the mal effects of the cold catalyst are mitigted.
The used cars don't get crushed as soon as the first owner is done with them, they go onto the used market and hopefully allow less enviro-trendy people, who just want a new car, to replace the old gas-guzzler they'd been driving.
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.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
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.
Well you're assuming we'd keep the design of the gasoline engine similar. If we start using the idea of electricity as a virtual transmission then it's possible to make gains.
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?
Introducing the new Occam Fusion! Now with sqrt(-1) fewer blades!
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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 liter engine. Also, the seats were uncomfortable, and my ignition switch assembly caught fire while I was driving one day.
The 2006 VWs may be better, but my sister-in-law bought a 2004 Jetta, new, and it was totalled when the electric seat heater caught fire.
BMW, on the other hand, is fine. I have fond memories of my Dad's 1984 318i, and wish I still had it.
-- Jeff Paulsen