EA and WYK: Diesels over electrics?

Here's a non-technical story from _The Economist_ on where diesels are going, and why electrics are going to have a very high hurdle to jump:
http://tinyurl.com/n8fundx
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Ed Huntress

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Kidding's only hurdle is clearing GMs dick, before he swings on it.
Electrics *already* have a bit of a hurdle. VW Golf et al lightfoots already claim near-60 mpg, and I think I read somewhere of diesels getting 70. Even tho the 100 mpge's of all electrics sound iimpressive, if you do the $$ calcs, the savings is perty small over 70 mpg..
Sheeit, Ed, you been ig'ing my posts? That closet fagit Kidding ALREADY has a 75+++ year ROI over my shitty li'l 40 mpg Fit... which is ackshooly a great car -- assuming the unwashed asses out there don't require leather seats.... Why assholes prefer to sweat on leather, Idk.... no pun intented.... lol
The main pro'leng with these high effic diesels is they are (apparently) expensive to build, expensive to maintain, very expensive to fix. Proly not as 'spensive to fix as the Volt, but still.....
Now, this article purports that the new diesels, by lowering compression ratio, solve the above costs AND improve efficiency.... I doubt it. If they've dropped the CR to 14 (from a max of 22, iiuc), why not drop it to to 10? or 7? They claim better mixing from the lowered CR, for better effic.... OK But what about effic LOSSES from the lowered CR? Increased effic from reduced engine weight?? PLease.... why not just reduce the weight of the frame/body, instead, and keep the high compression?.
And this:
"Unfortunately, the fuel and air at top dead-centre are rarely mixed as thoroughly as necessary for complete combustion. And because ignition takes place in the presence of a surplus of oxygen (from the highly compressed air), this incomplete combustion produces soot particles and smog-forming nitrogen oxides-the curse of traditional diesel engines."
Incomplete combustion from surplus oxygen??? Dats not what Moi lerntid in chemical school.
So, ahm not really disagreeing with the article, just questioning some of the causal connections. I hope these diesels DO deliver.... I just don't think the above are thoroughly cogent explanations.
AND, the BIGGIE Q: What will the upfront banging of the consumer be?? Will my shitty li'l Fit hand these diesels a(nother) 50+ year ROI ass-whupping?? LOL
Some time ago 2-stroke engines were being bandied about as the New (poh-tential) Green Thing. Long live the Kawasaki H3 750 2-stroke triple. If they put wings on dat thing, it woulda taken off into the air.... lol
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EA




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On Mon, 8 Jul 2013 22:06:41 -0400, "Existential Angst"

As I said, that's a non-technical article that tells you where the car manufacturers are going with diesels. They're getting close to 50% thermal efficiency. Another 20%, as the article claims is coming, would put them up in the range of the very best combined-cycle electric powerplant generators -- close to 60%.
As for the technical side, there really is only one place to get your answers: the Society of Automotive Engineers. They have hundreds of white papers on the subject. They cost a bundle, but the abstracts are free, and you can get the bottom lines from them. Trying to figure it out from chemistry and elementary physics won't do it. The dynamics of those engines are very subtle.
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What'd you think of the "incomplete combustion from too much oxygen"?? Reporters.... writers.... editors <aack>

It's good that alternatives are being pursued. Hopefully one technology won't bury the other, but that each will spur the other. Can you say, "Diesel AngstMobile", boyzngerlz?? lol
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On Tue, 9 Jul 2013 08:08:02 -0400, "Existential Angst"

That one threw me, and it's probably a mistake. HOWEVER -- and this is where things get subtle -- a lean mixture first gets a little hot as you start to lean it out, and then it gets COLD as you lean it out further. Less fuel burning in a given volume of gas puts less heat into the burning mixture. With spark ignition, you quickly reach a point where it won't even ignite -- except with stratified-charge, direct injection, designed to burn very lean mixtures. There are such engines in the labs.
What I think is that they meant more *air*, not more oxygen. But I don't know. I'd need to see an engineering report on it because I can visualize a lean mixture that's burning too cold to get complete combustion of some of the higher-flash-point components of the fuel.
I'm not about to assume anything. _The Economist_ is pretty good at fact-checking.
And before you dismiss reporters/writers/editors, I'll remind you that I'm a reporter/writer/editor, and I check things like that out carefully before publishing anything. d8-)

The question is whether hybridizing these diesels would produce enough benefit to bother with the electrics at all. The Europeans seem to think the answer is no. Remember, the gain for diesel hybrids is less than half that of spark-ignition hybrids, as we discussed before.
I'd like to see some results from those Bosch/Citroen experiments with diesel hybrids, but not enough to spend time looking for them.
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But you have a traditional education.
Read Yahoo News or Motley Fool to see what bird-brained articles the young'uns write. They serve only as early warning canaries.
jsw
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On Tue, 9 Jul 2013 09:05:24 -0400, "Jim Wilkins"

I don't think it's the education as much as a traditional background in journalism. I started as an editor for the only trade magazine in history that won the National Magazine Award outright (American Machinist, 1969). We took accuracy *very* seriously. At least three editors read everything before it was published, and the first two were responsible for checking facts.
And then I spent 6 years as a medical editor, where one mistake could get an editor fired.
The crap on the Internet is not written by journalists. They may be educated, but they have never absorbed the ethics and discipline of the business. They all want to be pundits, where anything goes.
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And lazyassed pundits..... mostly what goes is paraphrased press releases..... and mebbe not even paraphrased....
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That was part of your OJT education. The chemistry profs told us that college only prepared us to understand the lessons we would hear on the job.

Watching big-name reporters interview politicians clearly reveals which were popularly chosen as leaders. There isn't a single network newsperson I'd vote onto the town's budget committee.
We see them here during the NH Primary debates. So far I've managed to stay off camera by prompting the reporters to share their own opinions and pretending to care what they think.
This last election the photographers seem to have switched from Banana Republic beige to North Face black for their distinctive uniform. Or maybe I don't see them often enough to keep up. All black or black + jeans was the tribal costume for backstage personnel when I was in theatre. jsw
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I was just checking to see if you were awake.... lol

By "benefit", I'm assuming part of that is ROI. As some of the banter here has shown, very little added cost over a base ice 40 mpg car (like, uh, my Fit) can be supported, even for 100 mpge -- to Kidding's ignerint chagrin..
Heh, when GM drops the price for the Gen2 Volt by $10K, dumbfuckKidding won't be able to give his volt away.... and I'm sure he had all kinds of resale value built in to his bullshit ultra-low cost to own.... LOL
Heh, but I got a great idea: Kidding can keep his Volt as a quiet backup generator for his barn.... which oughtta be quiet, for $40K.... iffin he can figger out how to drop 350 V to center-tapped 220.... lol
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EA



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On Tue, 9 Jul 2013 09:24:16 -0400, "Existential Angst"

No, I mean strictly in terms of fuel economy.

Of course, it depends on fuel prices. In Amsterdam right now, a US gallon of gas costs $9.09.
And it depends somewhat on whether you value driving in something other than a shitbox. <g> I drove my Focus out to Chicago last Fall. I can tell the difference between that and my Sonata, which I usually drive out there. I could put a value on it, if I had to.

If you're really serious about ROI, consider a moped. d8-)
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Ed Huntress wrote:

OK, is this "thermal efficiency" the same as thermodynamic efficiency? I find that hard to believe, and 50 + 20 = 70%, which seems impossible thermodynamically. Certainly, I don't think there's anything like that out on the road now.
I know a bunch of people worked on adiabatic Diesels some time ago, and it seems a concept that ought to work. Recover all that heat in the exhaust and use it to heat the intake air, then you can manage with lower compression. Compressing the air requires energy, but if you can extract it from (free) waste heat, you get a big benefit.
Jon
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wrote:

Yes.

It's 50% plus 20% of that 50% = 60%. But they're not there yet. There are some small diesels in the labs that approach or slightly surpass 50%. A few car-sized HCCI engines have gone well over 50%. The latest automotive turbodiesels are doing between 40% and 45%; possibly one or two percent more. And large, stationary diesels get up to 54%.

See above.

The theoretical Carnot efficiency of a diesel operating between 298K and 1750K is 83%. The potential is higher than for any turbines, including combined-cycle stationary electrical generators. They've made some breakthroughs over the past few years and I expect to see 50% within a year or two, for engines available in passenger cars.
With alternative fuels and the aforementioned HCCI, lots of lab engines are getting over 50% now.
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Ed Huntress wrote:

That's pretty exciting, and I am awaiting seeing this show up in cars. Might bring back the Diesel autos to the US.
Jon
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wrote:

It is exciting. I've never seen as much research activity on engines as we have going on now. The SAE papers are flying like snowflakes, and the researchers are trying every combination of fuels, ignition, supercharging, and so on that you can think of.
The ones to watch, short term to long term, are diesel and turbodiesel; homogeneous-charge, compression-ignition (HCCI); combined-fuel (two or more fuels at once, or at different times in the combustion cycle); and combinations of two or more of these things. Meantime, we have Atkinson-cycle engines for hybrids and gasoline spark-ignition with direct injection that still have more development room left in them.
Diesels, particularly, are being re-thought from the ground up.
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This Ragone chart gives the game away:
<
http://www.sciencemag.org/content/334/6058/935/F4.large.jpg

I think that SOFC is Solid Oxide Fuel Cell; this may be the chief long-term danger to internal combustion engines. If they can get the practical details worked out.
<http://en.wikipedia.org/wiki/Solid_oxide_fuel_cell .
Joe Gwinn
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wrote:

Yeah, practicality is the big roadblock for alternatives. That, and limited availability of solar and wind power, plus a real distribution difficulty for hydrogen. When you're getting your electricity from conventional sources and your hydrogen is reformed natual gas, there isn't a lot to encourage proliferation of alternative power sources.

Interesting. I've been waiting most of my lifetime for one of those brilliant alternatives to make it out of the science pages of the newspapers, and I'm getting old enough that it's been a very long time. d8-)
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Ed Huntress

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