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50% Efficiency Boost From New Fuel Injection System

chudnall notes a Technology Review story on a new gas engine injection system that promises increased efficiency of up to 50%. "The key is heating and pressurizing gasoline before injecting it into the combustion chamber, says Mike Rocke, Transonic's vice president of business development. This puts it into a supercritical state that allows for very fast and clean combustion, which in turn decreases the amount of fuel needed to propel a vehicle. The company also treats the gasoline with a catalyst that 'activates' it, partially oxidizing it to enhance combustion."

14 of 379 comments (clear)

  1. Not just "similar" to a diesel by John+Hasler · · Score: 4, Insightful

    It is a diesel.

    When is the two-cycle version coming out?

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    1. Re:Not just "similar" to a diesel by 0100010001010011 · · Score: 4, Interesting

      Yep, sounds exactly what it is.

      Transonic's injection system varies from direct injection in two ways: it uses supercritical fluids and doesn't require a spark to ignite the fuel. The supercritical fluid mixes quickly with air when it's injected into the cylinder.

      Not sure what is considered 'super critical' but diesel fuel under 180 MPa/26,000 psi is pretty super critical to me.

      Once the fuel is injected into the piston, the heat and pressure are enough to cause the fuel to combust without a spark (similar to what happens in diesel engines), which also helps provide fast, uniform combustion. Ignition can be timed to happen just when the piston is reaching the optimal point, so it can convert as much of the energy in the gasoline into mechanical movement as possible, without wasting energy by heating up the combustion chamber walls, as happens in conventional technologies. The company has developed proprietary software that lets the system adjust the injection precisely depending on the load put on the engine.

      So it sounds exactly like a diesel engine or VW's TSI gasoline engine.

  2. Those "up to" words again. by onion2k · · Score: 5, Insightful

    I hate "up to". Anything that claims an improvement of "up to" something is a essentially misleading. You won't get a real world improvement anywhere close.

  3. Re:Same old snake oil by eldavojohn · · Score: 4, Insightful

    Same snake oil that was being pitched at county fairs in the 1970s. Nothing to see here, please move along.

    Well, I don't understand how their scam is supposed to work if you're right. From the article

    The company has demonstrated the technology in its own test engine, and says it is currently testing it with three automakers. One key question is the impact the high pressures and temperatures will have on how long the engine lasts, Rocke says. The company, which is supported by venture-capital investments from Venrock and Khosla Ventures, plans to manufacture its system itself, rather than licensing the technology. It plans to build its first factory in 2013, and to introduce the technology into production cars by 2014.

    So pretty much I just have to sit back and wait for the major automakers to offer these cars? Sounds like the fresh country rube is insulated from the snake oil salesman by the car manufacturers who apparently are prepared to buy into it. On top of that, it looks like they're not looking to license this technology to these companies but instead build a plant to manufacture them. So, they're at quite a bit of risk and are probably pretty interested in seeing this thing through if they want a piece of the manufacturing action. If you're selling snake oil, you usually just want to be selling it and not heavily invested in it.

    If you have a citation of high pressure transonic combustion in the 1970s, I'd love to read about it.

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  4. I'm sceptical by Moraelin · · Score: 5, Insightful

    Actually, by the end of TFA (which I'll assume _you_ have read before making a RTFA demand of others) they get even more generous with the claims, and say it gets 98 MPG at 50 mph. (I.e., in a range where, sorry, but it's not _that_ aerodynamic.) I.e., basically 2.4l per 100 km on the highway.

    I'm sceptical of anything which proposes to simply double the amount of energy extracted from that gasoline, because, well, physics is physics. The efficiency of the cycle is capped the hard way by the max and ambient temperature difference, and short of inventing an engine which runs at thousands of degrees, the alternative would be that conventional engines were spewing out half the gas unburned. Which just isn't the case.

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    1. Re:I'm sceptical by Kotten · · Score: 5, Informative

      I'm sceptical of anything which proposes to simply double the amount of energy extracted...

      They claimed 50% increase of efficiency.

      ...the alternative would be that conventional engines were spewing out half the gas unburned. Which just isn't the case.

      The efficiency of combustion engines are ~20% so you could say that more than half is lost (80% actually). An increase with 50% would but it in the 30% range which seems reasonable to me.

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    2. Re:I'm sceptical by bkaul01 · · Score: 4, Interesting

      Modern gasoline engines running at their peak thermal efficiency points are at about 35%. Diesels are typically in the 40% range. But those thermal efficiency numbers are a bit tricky ... it's not even theoretically possible to get any work out of an engine using a thermodynamic cycle that's 100% efficient - the ideal Carnot cycle would be on the order of 70-80% across the same temperature difference. In the real world, something on the order of 50% thermal efficiency is probably attainable. Right now, we're working to push Diesels towards 45%, and it's requiring things like waste heat recovery systems - running a bottoming cycle to recover some of the wasted exhaust energy. There are a variety of more advanced cycles and combustion modes being actively researched too.

      Generally speaking, a gasoline engine's peak efficiency is achieved when it's wide-open and running at peak load. At other operating conditions, the efficiency is lower due to a variety of factors. One of the ways we're looking at improving low-load operation is by using what's called HCCI (homogeneous charge, compression ignition) combustion - like diesel, compression ignition is used, but like gasoline engines, the fuel and air are premixed. It sounds like that's what they're probably using here, with the supercritical injection being used to help enhance and control the ignition process (a big difficulty with HCCI).

      I don't buy that they could increase the peak thermal efficiency by anywhere near 50%, or that they could increase the thermal efficiency at a given operating condition by that much through supercritical injection alone. If they're comparing HCCI to traditional stoichiometric SI combustion, though, it could get close to that at low-load points where the throttled SI engine is at its worst efficiency points. The supercritical injection isn't the direct cause of that gain, but an enabling technology to help facilitate HCCI operation. All else being equal (i.e. same combustion regimes, etc.), the injection technology could only have an impact on the fuel/air mixing and thus the combustion efficiency (i.e. how much of the fuel is burned completely), which is already well over 90%; there's just not much room for improvement there.

      Even if it doesn't increase the peak thermal efficiency of the engine at all, though, it could make a significant difference in vehicle fuel economy by increasing the efficiency at low-load, off-peak conditions. Most of the FTP and NEDC drive cycles (US and Europe, respectively) are at low speed conditions, with quite a bit of idling and cruising, but very little hard acceleration. Increasing the low-load efficiency of the engine will have a disproportionate effect even if the peak efficiency remains unaffected.

  5. Re:If you post before this by Socguy · · Score: 4, Insightful

    No, they REPORT that they get 64 miles/gallon. Who verified this? Lots of startups make outrageous claims to suck in investors. Is this under optimal conditions? In the lab, the Prius gets amazing mileage too. How heavy is their prototype? That's one funky, aerodynamic looking car... why not use a standard automobile... you know, something that might actually be driven by you on your way to work.

    Oh, but I'm sure when the technology never quite makes it to market, die hard conspiracy nuts will claim some Oil company bought the technology only to destroy it so they can sell more oil.

  6. Fascinating... by nanoakron · · Score: 4, Funny

    Does the exhaust also smell like bullshit?

  7. Running Very Lean Re:Same old snake oil by AJ+Mexico · · Score: 5, Interesting

    It's been known for a long time that engines will run very efficiently if you run them very lean. In TFA, you will see that's what these guys are doing. The problem is that the engine then runs very hot, and the thing wears out in short order, or you have to make it out of unobtanium. They are also using unusually high pressures and temperatures. In the fine print, you will see they still have some work to do on verifying that the engines will last very long under this treatment.

    So, yes, it will get great miles/gallon, but probably not very many miles/engine.

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  8. Re:Same old snake oil by mcgrew · · Score: 5, Insightful

    Fuel injection wasn't very widespread in the 1970s. The snake oil then was a carburator, not fuel injector. I knew a mechanic who actually got hold of the plans and built one; it increased his gasoline mileage slightly (it was supposed to triple it), but the car performed like a dog. It did NOT actually increase efficiency.

    If an engine's efficiency is increased, not only will you get better mileage but better performance as well, although you can increase mileage without increasing efficiency (back in the old days it simply took a smaller carburator). There have been a LOT of engineering enhancements since the '70s. I had a '74 Pontiac with a four barrel carb, dual exhaust, milled heads on a 350 CI V8, it got 19 mpg tops on the highway (stick shift). That car was fast, would burn rubber in all gears. The car I'm driving now is an '02 Concorde. It's as roomy as the Pontiac, nearly as fast (automatic tranny, will burn rubber without a clutch to dump), but has a far smaller V6. At 50 mph I get 35 mpg, 28-30 at 68 mph (that's 100 kph for those of you in more civilized parts of the world; 1 km = .6 m iirc), and gets up to 20 mpg in the city, depending on traffic lights, etc.

    THAT'S increased efficiencey. Today's automotive engineers are awesome.

  9. Re:Same old snake oil by YeeHaW_Jelte · · Score: 4, Funny

    No no they don't propose using a different oil ... just preprocessing the gasoline ... I mean, who can imagine a car running one snake oil? How many snakes to the mile would that take?

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  10. Sounds like something else... by sackvillian · · Score: 4, Interesting

    This article describes a very similar process from a New York company that uses supercritical diesel fuel -- and they report much more sensible efficiency gains of up to 10%. They've only tested in a lab setting so far though.

    I found the article because I was looking for the supercritical points of gasoline, which is a complex mixture of many different hydrocarbons, making the critical points very tricky to estimate. Turns out they are 720K and 60Mpa, from the article above. Their system achieves temperatures this high (almost 400 degrees higher than normal fuel system operations) using exhaust heat. Given that higher temperatures mean improved efficiency, I'd buy the 10% they propose -- though I remain very skeptical abut the 50% proposed in this article.

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  11. Re:Same old snake oil by radtea · · Score: 4, Insightful

    On top of that, it looks like they're not looking to license this technology to these companies but instead build a plant to manufacture them.

    That alone should be a red flag, for several reasons.

    1) They are an engine technology company, not a manufacturer. How much experience to they have in mass production, supply-chain management, etc? Not a small learning curve.

    2) Tooling costs are high, increasing their capital needs, which is a convenient way of pulling more money out of their investors and therefore creating more opportunities to skim.

    3) By manufacturing themselves they don't have to reveal the "secret secret", just the "secret". Any attempt to independently verify their claims will be made vastly more difficult by not having a full and public disclosure of their trade secrets in patent documents or under NDA to a licensed manufacture. So this approach puts off the day of reckoning for a good long while, and during that time company insiders can happily pay themselves big fat bonuses. It will also be much harder to prove they were lying about the technology's potential when the house of cards falls.

    An engine technology company that's going to manufacture rather than license? Sounds too good to be true. Because it probably is.

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