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The efficient choice among combustion engines
Phys.Org ^ | 09-12-2013 | by Claudia Naegeli

Posted on 09/12/2013 8:20:16 AM PDT by Red Badger

ETH researchers redesigned the conventional diesel engine of a VW Golf to run on 90% natural gas. Credit: Tobias Ott / ETH Zurich

Video at link.

Researchers at ETH Zurich have developed an internal combustion engine that emits less than half the CO2 compared to a regular engine without compromising performance. This corresponds to fuel consumption of less than 2.4 l per 100 km. This natural gas-diesel hybrid engine is based on a system of sophisticated control engineering.

The global energy markets are changing. New extraction methods are tapping into oilfields and natural gas deposits that have been inaccessible until now. The US, for example, is able to cover up to 83% of its total energy needs today; the government is even planning to increase exports of natural gas in the future. And there are new developments on the horizon: natural gas may also become an important fuel for vehicles on America's roads, thanks to the work of Swiss researchers at the Institute for Dynamic Systems and Control at ETH Zurich. They have developed a natural gas-diesel hybrid powertrain that emits just half the CO2 without compromising performance.

Diesel fuel injection instead of an ignition plug

ETH researchers redesigned the conventional diesel engine of a VW Golf to run on 90% natural gas. Instead of a spark plug as is standard with natural gas engines, the engine is ignited with a small amount of diesel injected directly into the cylinder. In doing so, the researchers were able to achieve a highly efficient combustion with a maximum efficiency of 39.6%.

Natural gas-diesel engines already exist, and are used industrially where power is generated and used in one place – for example to operate large machinery. "In a vehicle, the engine speed and load change constantly, which means the engine system is far more complicated," explains Tobias Ott, a doctoral student in Professor Lino Guzzella's research group.

Innovative electronic combustion control

Ott developed the innovative electronic combustion control together with senior scientist Christopher Onder as part of his dissertation. A sensor that measures pressure in the cylinders plays a key part: using complex control algorithms, the researchers were able to adapt the amount and timing of diesel continually, allowing an engine system with highest efficiency. The researchers also linked the innovative natural gas-diesel engine to a small electric motor to further reduce consumption. However, it could also be installed in a vehicle without electric hybridisation, which would be crucial for industrial production in larger quantities.

Mass production – a possibility in five years' time

The researchers demonstrated the reduction in emissions with experiments on a specially designed test rig and recently published the results in the specialist journal Energies. This proof of concept also involves solving final technical problems. "At the moment, we are concentrating particularly on the temperature in the catalytic converter," says Ott. For the converter to get up and running, it has to reach at least 300 degrees. "Our combustion engine converts heat energy into mechanical energy with such efficiency that the exhaust gas is not warm enough to create sufficient heat, particularly after start-up," adds Ott. The researchers want to solve the problem by modified control of the engine during the warm-up.

Christopher Onder is convinced that the natural gas-diesel engine can be produced in series production in five years. "The prerequisite is that we find an industrial partner who can take charge of developing a prototype," he explains. The researchers believe that the success of their engine depends critically on its production costs. They stress that their solution may not be cheap, but it is comparatively cost-effective. And because their concept is based on technology that already exists, it can be implemented quickly and is the perfect bridging technology for the next 10 to 20 years. The researchers are already engaged in negotiations with a car manufacturer.


TOPICS: Business/Economy; Culture/Society; Technical
KEYWORDS: auto; car; cng; diesel; energy; engine; naturalgas

1 posted on 09/12/2013 8:20:17 AM PDT by Red Badger
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To: sully777; vigl; Cagey; Abathar; A. Patriot; B Knotts; getsoutalive; muleskinner; sausageseller; ...

Rest In Peace, old friend, your work is finished.....

If you want ON or OFF the DIESEL ”KnOcK” LIST jut FReepmail me..... This is a fairly HIGH VOLUME ping list on some days.....

2 posted on 09/12/2013 8:21:31 AM PDT by Red Badger (It is dangerous to be right in matters where established men are wrong. .....Voltaire)
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To: Red Badger

This doesn’t sound practical to me.

(1) Carbon build up will eventually cause pre-det issues with the natural gas being sucked in through the intake stroke, as the engine ages.

(2) Have to put two fuels in your car, granted it won’t be a lot of diesel all told, still annoying.

More practical would be if they had figured out a reliable injector pump design that could inject CNG into the cylinders at the required pressures for diesel ignition of natural gas. That is probably a very tough problem though... mechanically speaking. Also, increasing engine robustness while reducing weight, to handle the higher compression ratios required (ethanol takes 23:1, I’d expect natural gas to be somewhere between ethanol and diesel... have not looked this up).


3 posted on 09/12/2013 8:39:10 AM PDT by Aqua225 (Realist)
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To: Red Badger
I worked on partial Propane injection for a while about 10 years ago.

A sensor that measures pressure in the cylinders plays a key part...

...aaaand there's one of the major technical hurdles, at least as I'm aware of. I haven't looked into it in a while. That pressure sensor is going to see on the order of 100 million pressure cycles over the life of the engine. That's a lot.

4 posted on 09/12/2013 8:43:10 AM PDT by Jack of all Trades (Hold your face to the light, even though for the moment you do not see.)
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To: Red Badger
This corresponds to fuel consumption of less than 2.4 l per 100 km.

2.41 what per 100 km?

5 posted on 09/12/2013 8:43:46 AM PDT by saminfl
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To: saminfl

2.4 LITERS, That’s an ‘L’ not a ‘1”.........


6 posted on 09/12/2013 8:47:20 AM PDT by Red Badger (It is dangerous to be right in matters where established men are wrong. .....Voltaire)
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To: saminfl
If its Europe it must be Liters

And in the years prior to invention of petroleum fueled engines....machinery (pumps and lifts for coal mines) were fueled by pulverized coal.

7 posted on 09/12/2013 8:49:52 AM PDT by spokeshave (While Zero plays silly card games like Spades - Putin plays for keeps.)
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To: Red Badger

It doesn’t look to me like they’ve solved an important issue in natural gas-diesel engines. Surprisingly, it’s soot. Liquid fuel disperses quite evenly in a diesel combustion chamber. Gas doesn’t disperse evenly. This leaves pockets of gas rich zones which have insufficient oxygen, and create soot. You know, the black stuff you see coming from diesel trucks when they accelerate. It seems like some in the “Green” community don’t like this.


8 posted on 09/12/2013 8:52:05 AM PDT by norwaypinesavage (Galileo: In science, the authority of a thousand is not worth the humble reasoning of one individual)
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To: Red Badger
There are several new kinds of IC engines in the wings, two of which are unusually interesting:

http://www.angellabsllc.com

http://ecomotors.com

9 posted on 09/12/2013 8:59:42 AM PDT by varmintman
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To: Aqua225
(2) Have to put two fuels in your car, granted it won’t be a lot of diesel all told, still annoying.

We have "dual fuel" trucks in the US, that run on natural gas or diesel. While there's natural gas, it runs with gas plus a little diesel. When the natural gas tank is empty, it runs on pure diesel. This is a more practical arrangement until the natural gas infrastructure is built up better.

10 posted on 09/12/2013 9:06:04 AM PDT by PapaBear3625 (You don't notice it's a police state until the police come for you.)
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To calculate the CO2 emission from a fuel the carbon content of the fuel must be multiplied with the ratio of molecular weight CO2 (44) to the molecular weight Carbon 12 -> 44 / 12 = 3.7

Carbon Dioxide emission can be calculated as

qCO2 = cf / hf CCO2/Cm (1)

where

qCO2 = specific CO2 emission (CO2/kWh)

cf = specific carbon content in the fuel (kgC/kgfuel)

hf = specific energy content (kWh/kgfuel)

Cm = specific mass Carbon (kg/mol Carbon)

CCO2 = specific mass Carbon Dioxide (kg/mol CO2)


11 posted on 09/12/2013 9:09:24 AM PDT by smokingfrog ( ==> sleep with one eye open (<o> ---)
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To: varmintman

Angel Labs has a very old engine concept. Probably doomed to wankel status.

Not sure about the other design from EcoMotors. Looks very interesting. Submarine and some locomotive motors used that opposed piston tech, just not the opposed cylinder part.

The motors that were so reliable in subs, were never really popular in locomotives, they tended not to hold up in over the road use.


12 posted on 09/12/2013 9:13:38 AM PDT by Aqua225 (Realist)
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To: Aqua225
The Angellabs engine is not old.

http://www.angellabsllc.com/resourse.html

Best is to download the excel demo and watch it.

13 posted on 09/12/2013 9:16:11 AM PDT by varmintman
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To: Jack of all Trades

“...aaaand there’s one of the major technical hurdles, at least as I’m aware of. I haven’t looked into it in a while. That pressure sensor is going to see on the order of 100 million pressure cycles over the life of the engine. That’s a lot.”

Piezo might be able to do it.


14 posted on 09/12/2013 9:17:19 AM PDT by The Antiyuppie ("When small men cast long shadows, then it is very late in the day.")
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To: Red Badger

Thanks.


15 posted on 09/12/2013 9:32:47 AM PDT by saminfl
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To: varmintman

No disrespect: but lookup Otto Lutz and the swing piston engine. Old news, terrible design, all the Wankel sealing issues. The Wankel is dead for a reason, and the swing piston engine has not seen a commercial application yet.


16 posted on 09/12/2013 9:36:13 AM PDT by Aqua225 (Realist)
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To: Red Badger
Researchers at ETH Zurich have developed an internal combustion engine that emits less than half the CO2 compared to a regular engine without compromising performance.

And in a world where CO2 emissions don't matter because AGW is no longer an issue, we need to concentrate on the highest possible efficiency, regardless of the CO2 levels.

Lowering CO and NOX I can understand...

17 posted on 09/12/2013 9:42:14 AM PDT by Yo-Yo
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To: The Antiyuppie

That’s what we use - Kistler. They’re pricey and finicky. Not sure how well they last in continuous use. Not saying 100e6 + cycles isn’t possible. I just think it’s dicey for a low cost automotive part.


18 posted on 09/12/2013 9:47:37 AM PDT by Jack of all Trades (Hold your face to the light, even though for the moment you do not see.)
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To: Aqua225

Not even close, the swing-piton engine is a reciprocating engine, the Angellabs engine is not. Download the excel file and watch it.


19 posted on 09/12/2013 9:53:43 AM PDT by varmintman
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To: Aqua225

http://www.youtube.com/watch?v=i0XTU7gCZV4


20 posted on 09/12/2013 9:57:55 AM PDT by varmintman
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To: Red Badger
Hybrid?

Cummins Heavy-Duty Natural Gas Truck Engine is already on the market and Clean Energy Fuels is building a series of LNG fueling stations across the US Interstate highway system. Who needs a hybrid?
21 posted on 09/12/2013 10:04:10 AM PDT by slumber1 (My real name is Rusty Shackleford)
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To: varmintman

I looked at it, it’s swing piston, just a minor variant.


22 posted on 09/12/2013 11:45:22 AM PDT by Aqua225 (Realist)
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To: Red Badger; Yo-Yo
the researchers were able to achieve a highly efficient combustion with a maximum efficiency of 39.6%.

Is this a big jump? I thought the average for an internal combustion engine is 18-20%.

But, I'm finding claims that with direct injection, gasoline engines can get as high as 35% and diesel engines as high as 40%.

23 posted on 09/12/2013 12:09:54 PM PDT by justlurking (tagline removed, as demanded by Admin Moderator)
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To: justlurking

It’s a pretty good jump only if it can be done cheaply. As he said in the video, it’s uses only off-the-shelf hardware. Getting mfrs to adopt it is another matter entirely.....


24 posted on 09/12/2013 12:14:33 PM PDT by Red Badger (It is dangerous to be right in matters where established men are wrong. .....Voltaire)
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To: Red Badger

My goal is rollin coal.... Black smoke from my cummins irritates the hell out of Prius drivers for some reason.

We do have a TDI Veeeee DubYa Passat that gets great mileage . Actually hit 50mpg once, going down hill in a tail wind but average about 43mpg if we keep our foot easy on the pedal.

Sure wish EPA was never invented (jimmy carter sucks duck eggs) .... Some really nice turbo diesels across the pond that get 50+ mpg all the time and they can scoot to boot. The technology exists... Bring it here yesterday !

Stay safe Red Badger ! Thanks for the ping .


25 posted on 09/12/2013 2:43:17 PM PDT by Squantos ( Be polite, be professional, but have a plan to kill everyone you meet ...)
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To: Squantos

Nixon created the EPA..........


26 posted on 09/12/2013 2:51:44 PM PDT by Red Badger (It is dangerous to be right in matters where established men are wrong. .....Voltaire)
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To: Red Badger

My bad .... Jimmy carter still sucks duck eggs...:o)


27 posted on 09/12/2013 3:28:17 PM PDT by Squantos ( Be polite, be professional, but have a plan to kill everyone you meet ...)
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To: saminfl

It’s about 98 mpg.


28 posted on 09/12/2013 3:32:39 PM PDT by B Knotts (Just another Tenther)
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To: Red Badger

I have a new golf diesel. Is it the diesel engine?


29 posted on 09/12/2013 3:37:20 PM PDT by Chickensoup (...We didn't love freedom enough... Solzhenitsyn.)
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To: Red Badger

Ford had natural gas engines until about 10 years ago.


30 posted on 09/12/2013 3:37:40 PM PDT by KYGrandma (The sun shines bright on my old Kentucky home.....)
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To: Red Badger
Researchers at ETH Zurich have developed an internal combustion engine that emits less than half the CO2 compared to a regular engine>>>

Big whoop, what the hell difference does that make?

"Anthropogenic global warming" is a hoax, and since there hasn't been any warming for 19 years...the whole thing is a hoax.

31 posted on 09/12/2013 3:41:40 PM PDT by ROCKLOBSTER (Celebrate "Republicans Freed the Slaves Month")
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To: Squantos
Sure wish EPA was never invented (jimmy carter sucks duck eggs)

I thought it was Nixon.

32 posted on 09/12/2013 3:43:06 PM PDT by ROCKLOBSTER (Celebrate "Republicans Freed the Slaves Month")
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To: Aqua225

The pistons in the Angellabs engine are not swinging, nor ae they moving back and forth in any manner, they are moving around continuously in a circular race. Download the Ecel file and watch it.


33 posted on 09/12/2013 8:32:39 PM PDT by varmintman
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To: varmintman

I watched the video of the mechanism turning in the lab. It has vanes or pistons, whatever we want to call them, and there is still a lot of stopping and starting in that design. From the video, I couldn’t tell if it was complete stops or not, but that is no savior of the design.

Basically, you have to have this type of method to compress the fuel charge and flush the cylinders, and the translate the expanding gas into movement.

It will have sealing issues, longevity issues, oiling issues, and just general energy loss from components which accelerate and decelerate to provide the necessary actions to produce power. Not to mention due to the sealing issues, reduced compression, which also harms thermal efficiency.

There is just no working around that. Computer controls can boost combustion efficiency, optimize spark, etc. but they can’t extract water from rock, as it were.

This engine is much like a Wankel. It can support very high _power density_, but it is inherently inefficient. This is also a major limitation with gas turbines. Very high power density, low thermal efficiency due to low compression and sealing issues (there is no “seal” in a gas turbine).

True alternative power is the electric motor. Even the cheapest blender or golf cart motor is around 40% efficient. Electric is the future, should we ever run out of petrol to burn in our diesels or direct injected gasoline engines. Even if you take system efficiency into account with fuel cells, and take the worst fuel cell and the worst electric motor, the combined thermal efficiency (energy out over energy in), you will get 24%. A typical car engine while cruising at part throttle is around 10 to 15% (a gasoline engine increases in efficiency as the throttle opens, probably nearing 35% nowadays), due to pumping losses.


34 posted on 09/14/2013 10:44:04 AM PDT by Aqua225 (Realist)
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