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The new technology was tested on a Caterpilllar heavy duty diesel engine. It achieved a thermal efficiency of 53 percent much better than the most efficient auto diesel engines (about 45 percent) and better even than the most efficient diesel engine in the world -- a turbocharged maritime engine that is 50 percent efficient.  (Source: Caterpillar Equipment)

The new engine could cut U.S. oil consumption by 4 million barrels a day -- roughly the amount that the U.S. imports from the volatile Persian Gulf.  (Source: Flickr)
New engine could get better gas mileage than mild hybrids even

Diesel and gasoline are both great fuels from a chemical standpoint, each with its own unique advantages.  Diesel burns more completely, lubricates the engine better, produces less carbon monoxide, and is safer as it does not produce as much flammable vapors.  However it has its disadvantages -- older engines can have a greater danger of incomplete combustion, overall engine power is a bit lower, and diesel engines weigh more.

Gasoline on the other hand burns faster and produces more power (due to the faster burn, not the energetic content).  However, it also typically yields worse gas mileage than diesel, combusts less completely (in well-maintained engines), usually requires a spark to ignite, and produces more pollutants and flammable vapors.

Researchers at the University of Wisconsin-Madison, led by Professor Rolf Reitz have come up with an innovative solution -- an engine which blends diesel and gasoline fuels to get the best of both worlds.  They have designed an engine which they say will be 20 percent more efficient than traditional gas engines, while also lowering the emissions.  The new engine works via a technique called "fast-response fuel blending", which means that the engine mixes the diesel and gas to the perfect ratio for the current conditions.

Heavy loads (like that of commercial trucks) would warrant a 85 percent gasoline to 15 percent diesel mix, while light loads would typically induce a roughly 50-50 mix.  Normally the gas wouldn't combust in a diesel engine, but by adding just the right amount of diesel fuel, combustion is achieved.  In fact, the special mix lowers engine temperatures by as much as 40 percent drastically reducing the amount of energy lost to waste heat.  This allows the diesel engine to use cheaper low-pressure injection (typically in gas engines only), and burns the fuel more cleanly, producing less pollutants.

The researchers estimate that if all cars and trucks in the nation adopted the new engine, it would cut U.S. oil consumption by a third -- by 4 million barrels per day.  States Professor Reitz, "That's roughly the amount that we import from the Persian Gulf."

The engine was developed using theoretical models, then built using a Caterpillar heavy-duty diesel engine as a base.  The new engine achieved 53 percent thermal efficiency, an admirable result, considering the best diesel engine -- a massive turbocharged two-stroke used in the maritime shipping industry -- gets 50 percent.

Professor Reitz concludes, "For a small engine to even approach these massive engine efficiencies is remarkable.  Even more striking, the blending strategy could also be applied to automotive gasoline engines, which usually average a much lower 25 percent thermal efficiency. Here, the potential for fuel economy improvement would even be larger than in diesel truck engines.  What's more important than fuel efficiency, especially for the trucking industry, is that we are meeting the EPA's 2010 emissions regulations quite easily."

The one major downside is that the engine necessitates a second tank.  However, in order to meet EPA nitrous oxide emission regulations the only alternative for large diesel vehicles would be urea injection -- which would likely be more expensive, less efficient, and still require a second tank.  While there's no telling how soon the engine will start popping up in cars and trucks, it appears to be the best solution yet and the best alternative to mild hybrids.  Of course it could be combined with hybrid electric technologies for even great fuel efficiencies.



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well but for vehicle usage
By VultureTX on 8/4/2009 9:56:09 AM , Rating: 0
They never seem to mention the added weight over a similar power gas engine. Typically these occupy about 1.5 times the volume and at least twice the mass of a gas engine. Then you add in the weight of a diesel tank on top of that. Based on these added factors this makes for better sense for commercial trucks than for your micro two-seater passenger.




RE: well but for vehicle usage
By tastyratz on 8/4/2009 10:32:22 AM , Rating: 5
not necessarily. Diesel engines today aren't the same as the ones of yesteryear. There is a great likelihood that this will fit in your standard engine bay around the same size as any other engine. The only difference is a fuel mixing that takes place - likely some sort of regulator/splitter right at the fuel rail. While more complex its not that much different.
For example as well: The jetta and jetta tdi are reported as being the same weight on msn auto's

Today's diesel is EXCELLENT,and FUD like that is why its not so widespread in the states. Its extremely comparative.

Also, if your afraid of gas tank size... who said you need to carry more fuel? You just need DIFFERENT fuel... so you would likely have a dual spout on the side and run 2 half sized gas tanks (or 60/40 or whatever they choose to go with for the split)... if you have 1 15 gallon tank or 2x 7.5 gallon tanks you have the same qty of fuel overall. Because of the staggering increase of efficiency however you will likely see this used frequently in sub compacts with SMALLER gas tanks achieving the same range.

The question with this is if we will see adaptations at the pump to idiot proof a system like this... and are people competent enough to monitor 2 gas level gauges. What happens when it runs out of 1 fuel, can it limp home on the other?


RE: well but for vehicle usage
By JediJeb on 8/4/2009 10:50:42 AM , Rating: 5
With lower compression as stated in the article if you also include a spark plug in the design then you should be able to make it running on 100% of either fuel when needed.

This reminds me of what International Harvestor did back in the late 40's early 50's with their farm tractors. They had a small Gasoline tank, and a larger Kerosene tank. You started the engine on gasoline, then once it was hot switched to kerosene. Kerosene is about half way between gasoline and diesel on flamability/volatility so it would be similar to this mixture. Back in the 40's kerosene was cheaper than gasoline so this made sense to farmers. The engine would not start using kerosene because when cold it would not vaporise well enough to iginte, but once the engine was hot it ran great. I wonder if this is where they got the idea?


RE: well but for vehicle usage
By tastyratz on 8/4/2009 10:58:03 AM , Rating: 5
Actually you bring up another VERY valid point without realizing it:

This engine actually opens up the possibility of using a 100% biofuel diesel.

The issue with a lot of fat based biodiesel is solidification at lower temperatures... but if the engine can start and warm up on gasoline every time they can run coolant lines parallel with the diesel fuel line and back to the tank to heat it up. Then when the engine is up to temperature they can switch over and begin blending. A lot of biodiesel conversions do this manually with switches... but this really opens up the possibility to do it from the factory intelligently.


RE: well but for vehicle usage
By AEvangel on 8/4/2009 12:07:06 PM , Rating: 5
Yeah it would be nice if this was pursued more as a viable option, I know of a couple of local Midwest based VW TDI owners that use 100% Bio-diesel, they have a small like 2.5 gallon tank installed in their trunk for regular diesel to start their car on then flip a switch and start running on the 100% Bio-diesel that they make in their basement for like half to a third of the price of regular diesel.


RE: well but for vehicle usage
By Lord 666 on 8/4/09, Rating: -1
RE: well but for vehicle usage
By quiksilvr on 8/4/2009 2:15:48 PM , Rating: 2
What does that have to do with anything? Did you think people would actually rate that up or do you get off posting stupid comments to see if the -2 rating exists?


RE: well but for vehicle usage
By FITCamaro on 8/4/2009 3:12:26 PM , Rating: 2
Given the poster, I would assume he was joking.


RE: well but for vehicle usage
By Lord 666 on 8/4/09, Rating: -1
RE: well but for vehicle usage
By RivuxGamma on 8/4/2009 9:54:10 PM , Rating: 3
Biodiesel sounds nice and all, but it does produce more CO2 and more nitrogen oxides when burned than normal diesel.

I'm a bit skeptical of the findings, anyway. There's just plain less energy in the mixture when diesel is mixed with gasoline, regardless of how it's burned. It's possible that it's only something that can work in gigantic engines and the article does say that it's expensive.

I'll wait until there's further proof of this technology before I hang my hat on it.


RE: well but for vehicle usage
By Samus on 8/5/2009 10:40:03 AM , Rating: 2
a golf tdi is 179lbs heavier than a golf 2.5, and the golf 2.5 doesn't even have a turbo.


RE: well but for vehicle usage
By Amiga500 on 8/4/2009 12:53:43 PM , Rating: 2
Yup.

Ferguson did the same with TVO on the TE20 - a mix of petrol and paraffin - to start the engine, and diesel as a regular runner.


RE: well but for vehicle usage
By rudolphna on 8/4/2009 11:15:44 AM , Rating: 2
We already have one. I live in upstate new york, we have alot of diesel pumps up here at gas stations. The diesel nozzle is much thicker around than the gas one does, and won't fit in. I know this, because one day I wasn't paying attention, and picked up the diesel nozzle, and it didn't fit. Good thing. I would have been stranded at HESS till I could get my tank drained. DOH. The real problem is going to be keeping people from putting gas in the diesel tank. Maybe a square nozzle for Gas, big round one for diesel, or something.


RE: well but for vehicle usage
By Lord 666 on 8/4/2009 12:37:43 PM , Rating: 2
There are actually two sized diesel nozzles; one for cars and the higher rate intended for trucks.

While I understand the idea behind it, as diesels become more popular, they do need to standardize on size/form factor. Driving to and from Florida last year, came across one station that only had the large nozzle off of I85. Other than that, all other stations have the smaller and some have both.


RE: well but for vehicle usage
By tastyratz on 8/4/2009 3:08:48 PM , Rating: 3
well that's just it. While we have one now, its usually seperate. Filling a tank like that would be cumbersome and generally loathed by the public.

A dual feed single connector fuel nozzle that plugged in 1 way with 2 outlets would be a good adaptation if enough manufacturers agreed to make these engines with a true market penetration.


RE: well but for vehicle usage
By monomer on 8/4/2009 4:57:54 PM , Rating: 2
Lots of older model Ford Trucks had dual gas tanks, and I realy never heard anyone complaining about them. In fact, some guys loved them since they could just run two pumps and fill in half the time than if they had only one tank.


RE: well but for vehicle usage
By MrPoletski on 8/5/2009 3:38:58 AM , Rating: 3
Here in the UK we simply colour code the pumps, green is unleaded petrol, red (used to be) 4 star leaded and black is diesel.

The nozzles are the exact same size.

If you screw up and put the wrong fuel in your car, it's your own stupid fault.


RE: well but for vehicle usage
By axeman1957 on 8/5/2009 11:59:49 AM , Rating: 2
Pretty sure the US does that too... every diesel pump I have ever seen has been green, and the unleaded are black


RE: well but for vehicle usage
By MrPoletski on 8/6/2009 5:26:42 AM , Rating: 2
quote:
Pretty sure the US does that too... every diesel pump I have ever seen has been green, and the unleaded are black


uh-oh, opposingly colour coded pumps, that's a recipie for disaster if coming over here to visit;)

but that's ok, we don't mind foreigners breaking their cars over here and having to pay our mechanics to fix it :)


RE: well but for vehicle usage
By Spuke on 8/5/2009 1:04:08 PM , Rating: 2
quote:
The nozzles are the exact same size.
The nozzles are a different size here but the color coding is the same.


RE: well but for vehicle usage
By teldar on 8/4/2009 3:54:52 PM , Rating: 4
There you go with the logic and truth about diesels. Don't know what you're thinking.....

Realistically, I don't understand how someone can be alive today and posting on this site and not have ever heard of BMW, Mercedes, or VW diesels.

Incredible.

Apparently these cars are NOT too heavy to accelerate decently or get decent mileage.


RE: well but for vehicle usage
By tjr508 on 8/4/2009 5:06:12 PM , Rating: 2
They don't travel a million miles like an International either...


RE: well but for vehicle usage
By Ammohunt on 8/5/2009 3:51:08 PM , Rating: 2
you absolutely correct, I have personally driver on the german autobahn 140Mph in a na Audi with a 1.9L turbo diesel man that car hauled ass 140Mph at 3k rpm.


RE: well but for vehicle usage
By kattanna on 8/4/2009 12:02:54 PM , Rating: 2
the thing that scares me most about this is having 2 different fuels.

when i pull up to the pump, sometimes i see people who look like they are confused with 2 pump handles at the same pump, gas and diesel. but now.. they might have to use both, and i can EASILY see people putting the wrong gas into the wrong tank.


RE: well but for vehicle usage
By mvpx02 on 8/4/2009 1:32:06 PM , Rating: 2
If this takes off, I'd imagine we'll see a standard pump nozzle for it too... something with 2 seperate spouts next to each other.

Think of the positive & negative terminals on an electric plug, they go into seperate holes and 1 is too big to fit into the smaller hole, so there is only 1 way to fit it in.


By wetwareinterface on 8/5/2009 1:09:27 AM , Rating: 2
that's the beauty of this engine in case you missed it in the article it can run on 100% gas or a mixture of gas and diesel. if some tard at the pump puts gas in his diesel tank side by accident he simply can drive till the gas is gone from the diesel tank if the manufacturer of the engine puts in a fuel sensor or the engine sensor registers too much of a power increase over what it's predicting for the fuel mix to be and assumes it's got gas in the diesel tank. diesel is thicker at lower temperatures than gas and can be sensed by flow and pressure required at the fuel pump. add in a temp gauge to the onboard engine computer and it could easily calculate if gas is in the diesel tank and come close to measuring the current fuel's mixture levels by the pressure level at the fuel pump and flow rate at the mix nozzle


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