Re: adding water to fuel
- From: clare at snyder dot ontario dot canada
- Date: Thu, 13 Mar 2008 23:38:11 -0400
On Thu, 13 Mar 2008 21:52:59 -0400, "Ed Huntress"
<huntres23@xxxxxxxxxxxxx> wrote:
<clare at snyder dot ontario dot canada> wrote in message
news:0hhjt3til4od2evegq7667u9m96cgauv3f@xxxxxxxxxx
On Thu, 13 Mar 2008 17:36:32 -0400, "Ed Huntress"
<huntres23@xxxxxxxxxxxxx> wrote:
It's a scam. Most of what you were told is not true. First, the most
efficient industrial processes for electrolysis of water run around 65%
efficiency. Theoretical peak efficiency lies in the 80% range. Nothing you
can do in a car-scale setup is going to come close to either figure.
That's
*before* you burn the hydrogen, which, like the real fuel, will burn at an
overall efficiency approaching 28% at best. That's a matter of physics and
the temperature limitations of the process, not inefficient design. So
you've lost at least 50% before you start, then the results may be running
at around 26% of *that*, given excellent design.
This could get tedious so I'll let someone else take over after this, but
throttle restriction has nothing whatever to do with the efficiency of
diesels. Diesels are efficient for three reasons: they always run at their
nominal compression ratio;
And how is this possible other than the FACT that a deisel engine is
unthrottled. Unthrottled means less pumping losses - and therefore
higher efficiency.
The diesel engine is unthrottled. A modern throttled, spark-ignition,
fuel-injected engine has no significantly greater restriction, when it's
running at full throttle. And the pumping losses are trivial in either a
spark-ignition OR a diesel, compared to the loss of thermal efficiency that
results from the lower effective compression ratio in the spark-ignition
engine.
If you said that the throttle results in less filling of the cylinder at
part-throttle operation, and that the resulting lower effective compression
ratio shot thermal efficiency to hell, you'd have it. But pumping losses,
even at part throttle, are not the significant issue. Not in an injected
engine, which is to say, virtually all modern automotive engines.
Ed - you did not read what I wrote very well - I said "at less than
full throttle" and pumping losses "at less than full throttle" are
virtually no different between a properly sized carb and a fuel
injection system, as at full throttle their manifold pressures will be
almost identical.
Not the WHOLE advantage but a very large one.
that compression ratio is very high; they can run
at mixtures leaner than stoichiometric (too much air) without losing much,
if any, efficiency. And they always do run lean, at any part-throttle
setting.
There is practically no loss in efficiency today that results from poor
ignition in a spark-ignition engine. Ignition in modern engines is not a
limiting factor.
You are missing the point and not fully understanding the issue..
Gasoline spark ignition engines can not run excessively lean because
you cannot ignite an over-lean mixture. The theory expounded here
(whether true or not) is that a hydrogen augmented mixture would light
even if terribly lean, making the lean mixture possible with gasoline
as well as with deisel.
Chrysler and Honda experimented with all kinds of ignition and lean mixtures
back in the '70s. After a brief, initial increase in efficiency (and
combustion temperature) as you pass stoichiometric on the downside, thermal
efficiency actually falls off as the mixture is leaned further.
As I said, It is EXTREMELY difficult to light and burn an extremely
lean mixture of gasoline and air effectively (and therefore
efficiently). Adding a bit of Hydrogen could make a huge difference as
the flamability range of hydrogen is MUCH wider - and if the hydrogen
burns and provides adequate heat, the lean fuel mixture could burn
smoothly as well. Not saying it WOULD, but the theory is viable. Same
thing happens with propane augmentation in a deisel - virtually NO
particulates as the fuel burn is MUCH more complete with the aid of
the "dry gas" fuel component (Propane).
It's a case of chasing your tail. With spark ignition and normal
compression, fuel efficiency doesn't get much better than it is at
stoichiometric mixtures, no matter how lean you go. And, at the slightly
lean mixtures where there *is* a slight improvement in fuel efficiency,
you're in the combustion temperature range where you generate large amounts
of NOx. All it all, it wasn't worth it.
But NOx isn't the issue here, of course, and there are benefits to running
somewhat lean. And yes, research shows that hydrogen, in some combinations,
lets you run leaner. But it's not that simple.
Remember, the only reason a deisel runs lean
at less than full power is because it is a NON THROTTLED engine. Power
output is controlled by controll fuel only, not air as in a spark
combustion engine.ing
Yeah, I know.
Again, it's a scam. Making scams sound "plausible" is how people scam
other
people. d8-)
I think it's a scam too, but the theory IS SOUND - even if it doesn't
work out in practice.
Which theory? The idea of adding hydrogen to the mix in a SI engine is based
on sound theories. It's being experimented with all over the world. Some
university in Norway has been publishing papers on it, and I've seen others.
It's very tricky to get the supposed benefits. It ain't going to happen with
some piece of bolt-on junk that runs on an otherwise normal engine.
For reference, the researchers are using various types of hydrogen
generators; mostly using an external source of power, for the experiments.
One generator I read about was producing around 5% hydrogen mixtures (the
minimum that seems to give a benefit) and requires 2.4 kW of power in a
highly efficient thermal/electrolytic setup. Now, running at a typical 50%
or so efficiency, a car alternator would require close to 7 hp just to
generate the electricity to produce the hydrogen in such a setup -- and a
400-amp alternator, running at peak output all the time.
What do you think these little "electrolytic crackers" are running at?
Certainly nothing like that. What they're doing is borrowing some theory and
exploiting it to produce a scam. How long have "water crackers" like that
been around? I remember seeing ads for them when I was a kid. They were a
scam then; they're a scam now.
The theories that Half-Nutz were talking about, which you've sort of picked
up on, are what I said were wrong. Look at this statement he made, based on
what he was told:
"Since it can still light in a lean state, you can do without the
throttle body, and lose the intake restriction, (just) one of the
reasons for a diesels better afficiency."
Now, how does lean burning eliminate the need for a throttle body? How do
you then throttle an SI engine? Somebody was handing him a line. I was
surprised to see your comment about restriction; maybe you missed what he
actually said. Are you suggesting that you don't need a throttle with this
engine?
IF you could properly combust an extremely lean fuel mixture you COULD
control the output of the engine STRICTLY by the amount of fuel
injected - just like in a deisel - with no throttle. And IF you could
do this, there would be virtually NO NOX produced because the excess
air at idle would cool the combustion gasses enough to keep the
nitrogen in the air from being oxidized - same principal as EGR if you
study it a bit closer.
I doubt the amount of hydrogen produced by in on-car cracker would be
sufficient to provide this range of combustibility - if hydrogen is
even the fuel most suited for this "experiment" - but it is DEFINITE
that IF you could acheive a wide enough combustibility range, a spark
ignition engine COULD be run throttle-less and still have reasonable
power control.
Low power/speed operation would be tricky, but on a hybrid the low
speed could be regulated by controlling the load of the generator -
and when no power was required the engine could be shut off as in
current synergy drive practice.
Anyway, from here we'd have to look at a specific system to see just where
the scams are.
--
Posted via a free Usenet account from http://www.teranews.com
.
- References:
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- Re: adding water to fuel
- From: Ed Huntress
- Re: adding water to fuel
- From: Half-Nutz
- Re: adding water to fuel
- From: Ed Huntress
- Re: adding water to fuel
- From: clare at snyder dot ontario dot canada
- Re: adding water to fuel
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