BMW Goes Old School With Steam Power

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BMW Turns to Steam to Boost Power, Improve Fuel Economy

MUNICH, Germany -- BMW is applying steam-engine technology in an auxiliary drive that the automaker says can boost both power and fuel efficiency in ordinary piston-driven cars.

The automaker is testing a two-stage device called the Turbosteamer on a stationary conventional 1.8-liter engine at BMW headquarters here.

The device works entirely on the waste heat from the engine.

Turbosteamer converts more than 80 percent of the heat energy in the exhaust into usable power, says Raymond Freymann, head of BMW's advanced research and development subsidiary.

BMW could start building production vehicles with the system by the first half of the next decade, Burkhard Goeschel, BMW board member for r&d, said during a briefing.

The system can be used on any combustion engine.

In trials on a test rig, the system when attached to a regular BMW four-cylinder, 1.8-liter Valvetronic engine reduced fuel consumption by 15 percent. It also generated an extra 13 hp and 14.8 pounds-feet of torque.

The concept is hardly new. The first patent for a steam auxiliary drive harnessing exhaust heat was issued in 1914 to Wilhelm Schmidt of Germany.

The sheer size of a heat-recovery system had been the biggest problem. But the Turbosteamer fits in a regular 3-series body.

"All we lose is a bit of ground clearance," says Freymann.

BMW knows that a production version of the Turbosteamer system must provide enough benefit to justify the higher price tag.

Says Freymann: "The clients have to save more fuel than the system's extra cost."

How the system works
BMW's system uses two fluid-circulating systems to recover exhaust heat from the gasoline engine. The primary high-temperature circuit pumps water through a heat exchanger, surrounding the exhaust gases immediately behind the catalytic converter. Water is heated to 1,022 degrees Fahrenheit.

Steam is converted into mechanical energy in an expander and transferred by pulleys to the engine crankshaft.

The steam flows through another heat exchanger and transfers its remaining heat to a second circuit filled with ethanol. This lower temperature system replaces the engine's regular coolant system.

This system also collects heat in a heat exchanger in the exhaust-gas flow. It releases its energy in a second expander unit that transfers the energy to the crankshaft.

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1. Radiator/ low temperature condenser 2. Pump 3. Steam generator 4. Steam generator/ high temperature condenser 5. Superheater 6. Steam generator/ low temperature condenser 7. Low temperature expander 8. High temperature expander



I have no idea what's going on, but I thought that you guys would like it.

Autoweek.
 
Hahaha.

It's no wonder BMW decided to go turbo. Hotter engine = better steam. I wonder if the exhaust note is going to have a chuggalug sound added on.
 
Awesome idea!.... Only doubt is, there is no mention of the additional weight it adds...

You could also adapt regenerative braking to this system, hook up a compressor in the driveline and engage it during braking to compress the steam for further "boost" (don't steal my idea BMW!).
 
Vonie
The primary high-temperature circuit pumps water through a heat exchanger, surrounding the exhaust gases immediately behind the catalytic converter. Water is heated to 1,022 degrees Fahrenheit.
:odd: That doesn't seem possible.
 
I don't know how hot a turbo engine's exhaust is, but it sounds reasonable. My technician friend says that most catalytic converters on normal engines don't get up to "operating temperature" until they reach about 600F-700F. The first cat, nearest the engine, probably gets well over 1000F. It has to in order to heat the water to that high a temperature. I wonder how long the water takes to travel through the cat, because it doesn't heat up very easily.
 
I believe it adds about 150 lbs, as its mostly empty piping with high pressure gas, and a couple extra accessory drives.

It is a neat idea, quirky as hell too, very BMW.
 
keef
The first cat, nearest the engine, probably gets well over 1000F. It has to in order to heat the water to that high a temperature. I wonder how long the water takes to travel through the cat, because it doesn't heat up very easily.
The exhaust would have to be well over 1000 degrees to vaporize the water, and then heat it another 800 degrees, especially considering how short a time the exhaust spends in the system.
 
Well considering many performance cars have unburned gas ignited at the exhaust tips, taking into account that the uncombusted air-to-fuel ratio is around 14:1 when you're up there in the rev range, and straight gasoline ignites at roughly 500 degrees Farenheit, the exhaust tempurature would have to be quite considerable to ignite the air-fuel mixture.

I'm not advanced enough to calculate the exact temperatue it would have to be to ignite it, but I'm sure there are some scholars out there that are more capable.
 
The water isn't necessarily boiled by the exhaust, but by the heat exchanger. It heats up quickly and transfers heat easily, so not much would be wasted. I'm pretty shure the exhaust temperature would be well over 1000F, so the exchanger would also be around that temperature, maybe just a little lower. That's plenty hot to vaporize water on contact. Turn on your mom's clothes iron on high and spray some water froma squirt bottle on it. Just drench it. Pssshhhhhhh, the water is gone in no time. It would work, and the steam would be under such high pressure that it would stay scalding throughout the pipe journey.
The only problems I see with this system are the awkwardness of its packaging and its weight. I'm pretty sure those engineers have it figured out, though.
 
keef
The water isn't necessarily boiled by the exhaust, but by the heat exchanger.
Do you know what a heat exchanger is?
keef
I'm pretty shure the exhaust temperature would be well over 1000F, so the exchanger would also be around that temperature, maybe just a little lower. That's plenty hot to vaporize water on contact. Turn on your mom's clothes iron on high and spray some water froma squirt bottle on it. Just drench it. Pssshhhhhhh, the water is gone in no time.
Yeah, but water vaporizes at 212F. You still have to heat it another 800 degrees in this system. Even if the temperature of the heat exchanger tubing is 1022 degrees, the rate of heat transfer slows greatly the hotter the steam gets. The steam itself would never get to 1022 F (theoretically, this would require infinite time and infinite heat exchanger area). So again, the temperature of the exhaust gas would have to be much higher than the purpoted 1000 F to get the steam to that temperature.
keef
It would work, and the steam would be under such high pressure that it would stay scalding throughout the pipe journey.
By my estimate, the steam pressure would be about 3 atmospheres (about 45 psi). That's not particularily high for the type of system they're talking about.

I don't doubt the legitimacy of this system. I just think that some of the numbers they're bandying about are fishy.
 
Big exhaust, small steam pipes. If they're talking about only 13hp, I don't doubt that it's a very small amount of water.

And yes, temperatures post-cat can reach that high. I'd bet this system makes more power the more you rev the engine. If they can keep the price and complexity low, it would be worth the added weight. From the looks of the diagram, it's not that complex at all.

I was confused at first by the radiator lines... but apparently, that's pure eth... it's one of those non-water cooling systems, probably a lifetime-sealed type, like the new Focus uses.
 
Think what happens when some of the near major supercar, and major supercar companies start to use this kind of tech.
 
TVR&Ferrari_Fan
Think what happens when some of the near major supercar, and major supercar companies start to use this kind of tech.

I highly doubt they would, This is more about efficiency not out right performance, the extra weight wouldn't justify the performance increase (which could be made up easily other ways) on a supercar.
 
SRV2LOW4ME
I'd buy one aslong as it comes with a train whistle. WOOT WOOT!

Man, that made me belt out with laughter. Good one.
 
Hah! BMW just started toying with turbos again and has already came up with a way to make them better. :sly: </snob>

VIPERGTSR01
TVR&Ferrari_Fan
Think what happens when some of the near major supercar, and major supercar companies start to use this kind of tech.
I highly doubt they would, This is more about efficiency not out right performance, the extra weight wouldn't justify the performance increase (which could be made up easily other ways) on a supercar.

Yeah, it's kinda like BMW's Valvetronic throttle-less intake system. Great for efficiency, but you won't be finding it on any ///M engine...

Who knows? Maybe this steamturbo has performance-engine potential...
 
Wolfe2x7
Hah! BMW just started toying with turbos again and has already came up with a way to make them better. :sly: </snob>



Yeah, it's kinda like BMW's Valvetronic throttle-less intake system. Great for efficiency, but you won't be finding it on any ///M engine...

True, but you never know, Valvetronic mixed with Double Vanos gives a quite a good Varible valve timing and lift system.
 
I think it's a cool idea. It reduces Co2 emissions, help prevent the effects of global warming, and makes it more powerful and gives it better response. I hope they go along with it.
 

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