H2 Combustion-Booster Claimed

Here's one I just read:

http://www.canada.com/montreal/montr...ry.html?id=cfe...

Some fellow is claiming he has a small device that will boost
combustion efficiency and save drivers lots of money, while reducing
emissions.

Obviously, plenty of claims have been made before, so I'm asking --
does this sound on the level?

It sounds reasonable that injecting H2 into your fuel stream can
improve the combustion. I assume that combusting the H2 in your
cylinders along with the regular fuel will boost temperature to give a
cleaner burn. Would the higher temperature harm your engine life at
all?

Since this device supposedly only holds a limited supply of distilled
H2O, KOH, etc which get periodically replaced, can I assume that it's
catalytically cracking some hydrogen from the hydrocarbon fuel stream
itself, so that hydrogen can improve the combustion of the remaining
fuel at the cylinder?

Is this somehow akin to a sort of turbocharger, but which uses hydrogen
instead of pressurized oxygen? Can it work for other things like
aircraft engines, in order to boost their operating ceiling?

Hmm, I dunno, I feel a little puzzled or suspicious of how he's
achieving a net energy gain here. Can anyone debunk any obvious
fallacies here?

Some fellow is claiming he has a small device that will boost
combustion efficiency and save drivers lots of money, while reducing
emissions.

Obviously, plenty of claims have been made before, so I'm asking --
does this sound on the level?


Water injection has been around for a long time, both for internal
combustion and aircraft jet engines, it does improve efficiency, reduce
temperatures and reduce some emissions. It depends what is being claimed for
the actual device.

Regards
Jeff

Water injection does not increase efficiency, it lowers it. The water goes
in as a liquid and goes out as a gas. The energy to do that comes from
burning fuel. It will always take more fuel to produce a given amount of
power with water injection than without. Water injection does allow higher
MP or higher compression so the engine can produce more power. Piston
engine fighters used it for more peak horsepower and some turbines use it
for the same purpose but it definately come at the price of higher fuel burn
per horsepower.

Mike


"Jeff" wrote in message
...
Some fellow is claiming he has a small device that will boost
combustion efficiency and save drivers lots of money, while reducing
emissions.

Obviously, plenty of claims have been made before, so I'm asking --
does this sound on the level?


Water injection has been around for a long time, both for internal
combustion and aircraft jet engines, it does improve efficiency, reduce
temperatures and reduce some emissions. It depends what is being claimed
for the actual device.

Regards
Jeff

"Mike Rapoport" wrote in message
ink.net...
Water injection does not increase efficiency, it lowers it. The water
goes
in as a liquid and goes out as a gas. The energy to do that comes from
burning fuel. It will always take more fuel to produce a given amount of
power with water injection than without. Water injection does allow
higher
MP or higher compression so the engine can produce more power. Piston
engine fighters used it for more peak horsepower and some turbines use it
for the same purpose but it definately come at the price of higher fuel
burn
per horsepower.

Mike

Hmm, consulting my ancient copy of Ricardo's "High Speed Internal Combustion
Engines", Sir Harry said that water injection can be substituted for any
excess fuel consumed for the purpose of reducing cylinder temperature and/or
increasing detonation margin. Further, evaporation of the water reduces the
intake charge temperature so as to reduce pumping losses. He goes on to say
that, while there is energy lost to evaporating the water droplets, the
overall fuel economy of an aircraft engine at max power setting will be
improved by use of water injection particularly if the compression ratio has
been increased to take advantage of the increased detonation margin.

Bill Daniels

"Bill Daniels" wrote in message
...

"Mike Rapoport" wrote in message
ink.net...
Water injection does not increase efficiency, it lowers it. The water
goes
in as a liquid and goes out as a gas. The energy to do that comes from
burning fuel. It will always take more fuel to produce a given amount of
power with water injection than without. Water injection does allow
higher
MP or higher compression so the engine can produce more power. Piston
engine fighters used it for more peak horsepower and some turbines use it
for the same purpose but it definately come at the price of higher fuel
burn
per horsepower.

Mike

Hmm, consulting my ancient copy of Ricardo's "High Speed Internal
Combustion
Engines", Sir Harry said that water injection can be substituted for any
excess fuel consumed for the purpose of reducing cylinder temperature
and/or
increasing detonation margin. Further, evaporation of the water reduces
the
intake charge temperature so as to reduce pumping losses. He goes on to
say
that, while there is energy lost to evaporating the water droplets, the
overall fuel economy of an aircraft engine at max power setting will be
improved by use of water injection particularly if the compression ratio
has
been increased to take advantage of the increased detonation margin.

Bill Daniels


Yes, water injection can replace fuel used for cooling. I was not precise
enough in my wording. In the case of using water injection at lower power
settings (where excess fuel for cooling is not used) efficiency will be
reduced. I used water injection in a Corvette that had 11:1 compression to
stop detonation. It worked but power was definately less than with high
octane gasoline and without water injection.

Mike

Mike Rapoport wrote:


"Bill Daniels" wrote in message
...

"Mike Rapoport" wrote in message
ink.net...
Water injection does not increase efficiency, it lowers it. The
water
goes
in as a liquid and goes out as a gas. The energy to do that comes
from
burning fuel. It will always take more fuel to produce a given
amount of
power with water injection than without. Water injection does
allow
higher
MP or higher compression so the engine can produce more power.
Piston engine fighters used it for more peak horsepower and some
turbines use it for the same purpose but it definately come at the
price of higher fuel
burn
per horsepower.

Mike

Hmm, consulting my ancient copy of Ricardo's "High Speed Internal
Combustion
Engines", Sir Harry said that water injection can be substituted
for any excess fuel consumed for the purpose of reducing cylinder
temperature and/or
increasing detonation margin. Further, evaporation of the water
reduces the
intake charge temperature so as to reduce pumping losses. He goes
on to say
that, while there is energy lost to evaporating the water droplets,
the overall fuel economy of an aircraft engine at max power setting
will be improved by use of water injection particularly if the
compression ratio has
been increased to take advantage of the increased detonation
margin.

Bill Daniels


Yes, water injection can replace fuel used for cooling. I was not
precise
enough in my wording. In the case of using water injection at lower
power settings (where excess fuel for cooling is not used)
efficiency will be
reduced. I used water injection in a Corvette that had 11:1
compression to
stop detonation. It worked but power was definately less than with
high octane gasoline and without water injection.

That's because you weren't running a lean mixture at high manifold
pressures while the water was going in. An integral part of ADI
(Anti Detonant Injection) systems on the big reciprocating airplane
engines was that the mixture would be leaned much closer to
stochiometric, and specific power and fuel burn would increase.
For example, the Wright R3350-32WA used on the P2V Neptune patrol
airplane, and on most Constellations and DC-7s, burned 45 lbs/minute
at max Dry Power (277 BMEP/2900 RPM), 'bout 3400 HP. The equivalent
info with ADI operating was 34 lbs/min at 301 BMEP/2900 RPM, giving
3700 HP. These engines generally ran on 115/145 Octane fuel.

While you can make water injection work by just dumping water in,
you don't get the full benefit unless you can adjust the fuel flow
properly.

--
Pete Stickney
Java Man knew nothing about coffee.

Mike Rapoport wrote:
Water injection does not increase efficiency, it lowers it. The water goes
in as a liquid and goes out as a gas. The energy to do that comes from
burning fuel.

Same thing is true of a steam engine. In a steam engine it is
the phase-change of the water that makes it possible to convert
the heat from burning fuel into mechanical energy.

It will always take more fuel to produce a given amount of
power with water injection than without. Water injection
does allow higher
MP or higher compression so the engine can produce more power.

The thermodynamic efficiency of a heat engine is a function of the
compression ratio. Increasing the compression ratio increases
the efficiency. That is not to say that with water injection
there are not also increased losses that negate that advantage,
but the fact remains that increased compression ratio, absent
other factors, increases efficiency.

Piston
engine fighters used it for more peak horsepower and some turbines use it
for the same purpose but it definately come at the price of higher fuel burn
per horsepower.


Ok, I believe you.

--

FF

wrote in message
oups.com...

Mike Rapoport wrote:
Water injection does not increase efficiency, it lowers it. The water
goes
in as a liquid and goes out as a gas. The energy to do that comes from
burning fuel.

Same thing is true of a steam engine. In a steam engine it is
the phase-change of the water that makes it possible to convert
the heat from burning fuel into mechanical energy.


Yes but the steam engine takes the high-energy water vapor and produces
mechanical energy while returning the water as a low energy liquid.

Mike

Mike Rapoport wrote:
wrote in message
oups.com...

Mike Rapoport wrote:
Water injection does not increase efficiency, it lowers it. The water
goes
in as a liquid and goes out as a gas. The energy to do that comes from
burning fuel.

Same thing is true of a steam engine. In a steam engine it is
the phase-change of the water that makes it possible to convert
the heat from burning fuel into mechanical energy.


Yes but the steam engine takes the high-energy water vapor and produces
mechanical energy while returning the water as a low energy liquid.


Actually the conversion to mechanical energy ceases before the vapor
condenses. Condensate in a turbine or even a steam piston is
undesireable.

Regarding water-injection of an internal combustion engine
I would assume the water is injected during the intake stroke,
evaporates completely or almost so near TDC and then mechanical
energy is extracted from the water vapor, along with the combustion
products, during the power stroke. One of those combustion
products was already water, so it's not like such an engine
doesn't already extract energy from expanding water vapor.

There is an increase in entropy associated with the phase change.
That energy is irretreiveably lost and probably accounts for
why the water-injected engine is less efficient than a 'dry'
engine despite the improved thermodynamic efficiency resulting
from the higher compression ratio.

But I'm not about to attempt the math. Entropy always make my
brain hurt.

--

FF

Mike

Yep

Big John
`````````````````````````````````````````````````` ```````````````````````````

On Fri, 23 Sep 2005 15:19:07 GMT, "Mike Rapoport"
wrote:

Water injection does not increase efficiency, it lowers it. The water goes
in as a liquid and goes out as a gas. The energy to do that comes from
burning fuel. It will always take more fuel to produce a given amount of
power with water injection than without. Water injection does allow higher
MP or higher compression so the engine can produce more power. Piston
engine fighters used it for more peak horsepower and some turbines use it
for the same purpose but it definately come at the price of higher fuel burn
per horsepower.

Mike


"Jeff" wrote in message
...
Some fellow is claiming he has a small device that will boost
combustion efficiency and save drivers lots of money, while reducing
emissions.

Obviously, plenty of claims have been made before, so I'm asking --
does this sound on the level?


Water injection has been around for a long time, both for internal
combustion and aircraft jet engines, it does improve efficiency, reduce
temperatures and reduce some emissions. It depends what is being claimed
for the actual device.

Regards
Jeff