Science > Physics > A gasoline generator with a 97% efficiency rating.
| Topic: |
Science > Physics |
| User: |
"Laurent" |
| Date: |
05 Mar 2004 10:25:49 AM |
| Object: |
A gasoline generator with a 97% efficiency rating. |
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
It's really very simple and low tech. It is basically an airplane
gasoline motor fitted with a sliding-vane turbine on the intake,
which would take advantage of the air flow created by sea level
atmospheric pressure. Since this would be an airplane engine whose
performance is supposed to peak at high altitudes, or at low
atmospheric pressures (airplane engine manufacturers do this by
simply using a specially grinded camshaft), and since my generator
is supposed to work at sea level, at standard atmospheric pressure,
the air flow restriction caused by the intake turbine would work to
its advantage. The extra power would come from a generator attached
to the intake sliding-vane turbine.
--
Laurent
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| User: "Franz Heymann" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 04:07:17 PM |
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"Laurent" <cyberdyno4@starpower.net> wrote in message
news:acOdnWcQQfd4NNXdRVn-ig@comcast.com...
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
(T1 - T2)/T1
Therefore the rest is nonsense.
[snip]
Franz
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| User: "Ian Stirling" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 11:51:19 AM |
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In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
The requestor should be interned in guantanamo bay.
You can't get 97% from an internal combustion engine on earth
for basic thermodynamic reasons.
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| User: "Opus Penguin" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 11:59:33 AM |
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Ian Stirling wrote:
In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
The requestor should be interned in guantanamo bay.
You can't get 97% from an internal combustion engine on earth
for basic thermodynamic reasons.
Heat loss is the biggest issue, no? Could they line the cylinder walls,
piston top, and valves with some sort of bakelite to keep the heat in the
chamber? That would help, wouldn't it? Also, don't they lose energy in
unspent gasses? Can't they put in 3 or 4 spark plugs per cylinder to make
sure they burn every last drop of fuel mixture?
--
____________________________
Pear pimples for hairy fishnuts?
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| User: "Greg Neill" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 01:07:30 PM |
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"Opus Penguin" <OpusPenguin@BloomCounty.nospam> wrote in message
news:9e32c.55898$vj5.42695@newssvr33.news.prodigy.com...
Ian Stirling wrote:
In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
The requestor should be interned in guantanamo bay.
You can't get 97% from an internal combustion engine on earth
for basic thermodynamic reasons.
Heat loss is the biggest issue, no? Could they line the cylinder
walls,
piston top, and valves with some sort of bakelite to keep the heat in the
chamber? That would help, wouldn't it? Also, don't they lose energy
in
unspent gasses? Can't they put in 3 or 4 spark plugs per cylinder to make
sure they burn every last drop of fuel mixture?
You dump and lose hot gases with every exhaust stroke,
regardless of how thoroughly combustion went. The
heat in the exhaust represents energy lost.
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| User: "Steve Ralph" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 01:25:14 PM |
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"Greg Neill" <gneillREM@OVE.netcom.ca> wrote in message
news:Td42c.100805$PU4.1263767@wagner.videotron.net...
"Opus Penguin" <OpusPenguin@BloomCounty.nospam> wrote in message
news:9e32c.55898$vj5.42695@newssvr33.news.prodigy.com...
Ian Stirling wrote:
In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
The requestor should be interned in guantanamo bay.
You can't get 97% from an internal combustion engine on earth
for basic thermodynamic reasons.
Heat loss is the biggest issue, no? Could they line the cylinder
walls,
piston top, and valves with some sort of bakelite to keep the heat in
the
chamber? That would help, wouldn't it? Also, don't they lose
energy
in
unspent gasses? Can't they put in 3 or 4 spark plugs per cylinder to
make
sure they burn every last drop of fuel mixture?
You dump and lose hot gases with every exhaust stroke,
regardless of how thoroughly combustion went. The
heat in the exhaust represents energy lost.
Rolls Royce are adressing converting this lost heat to power
http://www.coolchips.gi/press/pr_030707.shtml
Which if it works would increase the efficiency of the total system
SR
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| User: "Gregory L. Hansen" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 12:35:52 PM |
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In article <9e32c.55898$vj5.42695@newssvr33.news.prodigy.com>,
Opus Penguin <OpusPenguin@BloomCounty.nospam> wrote:
Ian Stirling wrote:
In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
The requestor should be interned in guantanamo bay.
You can't get 97% from an internal combustion engine on earth
for basic thermodynamic reasons.
Heat loss is the biggest issue, no? Could they line the cylinder walls,
piston top, and valves with some sort of bakelite to keep the heat in the
chamber? That would help, wouldn't it? Also, don't they lose energy in
unspent gasses? Can't they put in 3 or 4 spark plugs per cylinder to make
sure they burn every last drop of fuel mixture?
The Carnot efficiency of a heat engine is (T_hot - T_cold)/T_hot. That's
a theoretical maximum efficiency. You could line cylinder walls,
recirculate and reheat, add spark plugs, put turbines in the exhaust, and
anything else you want, and you won't beat Carnot.
An engine that reaches 97% of Carnot efficiency would at least be
believable.
--
"The average person, during a single day, deposits in his or her underwear
an amount of fecal bacteria equal to the weight of a quarter of a peanut."
-- Dr. Robert Buckman, Human Wildlife, p119.
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| User: "Laurent" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 02:32:29 PM |
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Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
--
Laurent
"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in
message news:c2aha8$3lc$1@hood.uits.indiana.edu...
In article <9e32c.55898$vj5.42695@newssvr33.news.prodigy.com>,
Opus Penguin <OpusPenguin@BloomCounty.nospam> wrote:
Ian Stirling wrote:
In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency.
Currently the
best they can do is about 65%, the rest is lost as heat.
The requestor should be interned in guantanamo bay.
You can't get 97% from an internal combustion engine on earth
for basic thermodynamic reasons.
Heat loss is the biggest issue, no? Could they line the
cylinder walls,
piston top, and valves with some sort of bakelite to keep the
heat in the
chamber? That would help, wouldn't it? Also, don't they
lose energy in
unspent gasses? Can't they put in 3 or 4 spark plugs per
cylinder to make
sure they burn every last drop of fuel mixture?
The Carnot efficiency of a heat engine is (T_hot - T_cold)/T_hot.
That's
a theoretical maximum efficiency. You could line cylinder walls,
recirculate and reheat, add spark plugs, put turbines in the
exhaust, and
anything else you want, and you won't beat Carnot.
An engine that reaches 97% of Carnot efficiency would at least be
believable.
--
"The average person, during a single day, deposits in his or her
underwear
an amount of fecal bacteria equal to the weight of a quarter of a
peanut."
-- Dr. Robert Buckman, Human Wildlife, p119.
.
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| User: "Greg Neill" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 03:09:30 PM |
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"Laurent" <cyberdyno4@starpower.net> wrote in message
news:Do-dnZj7iv13ftXdRVn-vA@comcast.com...
Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
What's creating the pressure difference to turn the
turbine? Power from the engine is.
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| User: "Laurent" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 03:29:33 PM |
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"Greg Neill" <gneillREM@OVE.netcom.ca> wrote in message
news:e062c.644$vj.36826@wagner.videotron.net...
"Laurent" <cyberdyno4@starpower.net> wrote in message
news:Do-dnZj7iv13ftXdRVn-vA@comcast.com...
Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
What's creating the pressure difference to turn the
turbine? Power from the engine is.
Right, but the engine is made to work at low atmospheric pressures
anyway, so it isn't affected. On the contrary, it would be adversely
affected if it were made to operate at sea level without any intake
restrictions.
Also keep in mind that when a vacuum cleaner is doing work (or
sucking up dirt) is when it uses the least energy, that's why the
centrifugal turbine speeds up if you block its intake.
--
Laurent
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| User: "Gregory L. Hansen" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 03:59:05 PM |
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In article <kaOdnVvy2uf3bNXd4p2dnA@comcast.com>,
Laurent <cyberdyno4@starpower.net> wrote:
"Greg Neill" <gneillREM@OVE.netcom.ca> wrote in message
news:e062c.644$vj.36826@wagner.videotron.net...
"Laurent" <cyberdyno4@starpower.net> wrote in message
news:Do-dnZj7iv13ftXdRVn-vA@comcast.com...
Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
What's creating the pressure difference to turn the
turbine? Power from the engine is.
Right, but the engine is made to work at low atmospheric pressures
anyway, so it isn't affected. On the contrary, it would be adversely
affected if it were made to operate at sea level without any intake
restrictions.
So it can run closer to its Carnot efficiency at low pressures, and would
be much less efficient at atmospheric pressure. It doesn't get 97% fuel
efficiency.
Also keep in mind that when a vacuum cleaner is doing work (or
sucking up dirt) is when it uses the least energy, that's why the
centrifugal turbine speeds up if you block its intake.
--
"And don't skimp on the mayonnaise!"
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| User: "Ian Stirling" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 03:48:38 PM |
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In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
"Greg Neill" <gneillREM@OVE.netcom.ca> wrote in message
news:e062c.644$vj.36826@wagner.videotron.net...
"Laurent" <cyberdyno4@starpower.net> wrote in message
news:Do-dnZj7iv13ftXdRVn-vA@comcast.com...
Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
What's creating the pressure difference to turn the
turbine? Power from the engine is.
Right, but the engine is made to work at low atmospheric pressures
anyway, so it isn't affected. On the contrary, it would be adversely
affected if it were made to operate at sea level without any intake
restrictions.
Err, no.
The engine works at its design pressure, and is not affected by that,
but it has to do work pumping the exhaust out.
This turns out to be less than the amount you'll get from the turbiune.
Also keep in mind that when a vacuum cleaner is doing work (or
sucking up dirt) is when it uses the least energy, that's why the
centrifugal turbine speeds up if you block its intake.
No, it's becaus the blades stall.
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| User: "The Ghost In The Machine" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
06 Mar 2004 10:59:47 AM |
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In sci.skeptic, Laurent
<cyberdyno4@starpower.net>
wrote
on Fri, 5 Mar 2004 15:32:29 -0500
<Do-dnZj7iv13ftXdRVn-vA@comcast.com>:
Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
Does it matter?
A theoretical Carnot engine converts heat to mechanical work at
efficiency (Th - Tc) / Th, which reprises the formula below. I'm
not up on my enthalpy, regrettably, but it's clear that, in order
to have a 97% conversion efficiency of heat to work, one has to have
(Th - Tc) / Th = 0.97
Th - Tc = Th * 0.97
Tc = Th * 0.03
Th = Tc / 0.03
Since Tc = 300 K (on a warm day), Th would therefore have to be
approximately 10,000 K.
I don't think gasoline burns that hotly. :-) The Sun's surface
is about 5800 K.
--
Laurent
"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in
message news:c2aha8$3lc$1@hood.uits.indiana.edu...
In article <9e32c.55898$vj5.42695@newssvr33.news.prodigy.com>,
Opus Penguin <OpusPenguin@BloomCounty.nospam> wrote:
Ian Stirling wrote:
In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency.
Currently the
best they can do is about 65%, the rest is lost as heat.
The requestor should be interned in guantanamo bay.
You can't get 97% from an internal combustion engine on earth
for basic thermodynamic reasons.
Heat loss is the biggest issue, no? Could they line the
cylinder walls,
piston top, and valves with some sort of bakelite to keep the
heat in the
chamber? That would help, wouldn't it? Also, don't they
lose energy in
unspent gasses? Can't they put in 3 or 4 spark plugs per
cylinder to make
sure they burn every last drop of fuel mixture?
The Carnot efficiency of a heat engine is (T_hot - T_cold)/T_hot.
That's
a theoretical maximum efficiency. You could line cylinder walls,
recirculate and reheat, add spark plugs, put turbines in the
exhaust, and
anything else you want, and you won't beat Carnot.
An engine that reaches 97% of Carnot efficiency would at least be
believable.
--
"The average person, during a single day, deposits in his or her
underwear
an amount of fecal bacteria equal to the weight of a quarter of a
peanut."
-- Dr. Robert Buckman, Human Wildlife, p119.
--
#191,
It's still legal to go .sigless.
.
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| User: "Fletch F. Fletch" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
06 Mar 2004 11:36:57 AM |
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"The Ghost In The Machine" <ewill@sirius.athghost7038suus.net> wrote in
message news:c6bph1-dh8.ln1@lexi2.athghost7038suus.net...
In sci.skeptic, Laurent
<cyberdyno4@starpower.net>
wrote
on Fri, 5 Mar 2004 15:32:29 -0500
<Do-dnZj7iv13ftXdRVn-vA@comcast.com>:
Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
Does it matter?
A theoretical Carnot engine converts heat to mechanical work at
efficiency (Th - Tc) / Th, which reprises the formula below. I'm
not up on my enthalpy, regrettably, but it's clear that, in order
to have a 97% conversion efficiency of heat to work, one has to have
(Th - Tc) / Th = 0.97
Th - Tc = Th * 0.97
Tc = Th * 0.03
Th = Tc / 0.03
Since Tc = 300 K (on a warm day), Th would therefore have to be
approximately 10,000 K.
I don't think gasoline burns that hotly. :-) The Sun's surface
is about 5800 K.
I refuse to drive beneath the sun's surface.
Slainte,
Fletch
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| User: "The Ghost In The Machine" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
07 Mar 2004 10:50:09 AM |
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In sci.skeptic, Fletch F. Fletch
<notme31415@yahoo.com>
wrote
on Sat, 06 Mar 2004 17:36:57 GMT
<Z_n2c.19460$YN5.807@nwrdny03.gnilink.net>:
"The Ghost In The Machine" <ewill@sirius.athghost7038suus.net> wrote in
message news:c6bph1-dh8.ln1@lexi2.athghost7038suus.net...
In sci.skeptic, Laurent
<cyberdyno4@starpower.net>
wrote
on Fri, 5 Mar 2004 15:32:29 -0500
<Do-dnZj7iv13ftXdRVn-vA@comcast.com>:
Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
Does it matter?
A theoretical Carnot engine converts heat to mechanical work at
efficiency (Th - Tc) / Th, which reprises the formula below. I'm
not up on my enthalpy, regrettably, but it's clear that, in order
to have a 97% conversion efficiency of heat to work, one has to have
(Th - Tc) / Th = 0.97
Th - Tc = Th * 0.97
Tc = Th * 0.03
Th = Tc / 0.03
Since Tc = 300 K (on a warm day), Th would therefore have to be
approximately 10,000 K.
I don't think gasoline burns that hotly. :-) The Sun's surface
is about 5800 K.
I refuse to drive beneath the sun's surface.
Good for you. :-) You might live longer that way. :-)
(Fun fact: it's impossible to get anything hotter than the
Sun's surface by using lenses and mirrors. Of course, the
Sun's surface is plenty hot (enough to melt and vaporise
anything I know of!) but in light of my computation above,
not hot enough.)
Slainte,
Fletch
--
#191,
It's still legal to go .sigless.
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| User: "Ian Stirling" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
07 Mar 2004 02:26:01 PM |
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In sci.physics The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.skeptic, Fletch F. Fletch
<notme31415@yahoo.com>
wrote
on Sat, 06 Mar 2004 17:36:57 GMT
<Z_n2c.19460$YN5.807@nwrdny03.gnilink.net>:
"The Ghost In The Machine" <ewill@sirius.athghost7038suus.net> wrote in
message news:c6bph1-dh8.ln1@lexi2.athghost7038suus.net...
In sci.skeptic, Laurent
<cyberdyno4@starpower.net>
wrote
on Fri, 5 Mar 2004 15:32:29 -0500
<Do-dnZj7iv13ftXdRVn-vA@comcast.com>:
Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
Does it matter?
A theoretical Carnot engine converts heat to mechanical work at
efficiency (Th - Tc) / Th, which reprises the formula below. I'm
not up on my enthalpy, regrettably, but it's clear that, in order
to have a 97% conversion efficiency of heat to work, one has to have
(Th - Tc) / Th = 0.97
Th - Tc = Th * 0.97
Tc = Th * 0.03
Th = Tc / 0.03
Since Tc = 300 K (on a warm day), Th would therefore have to be
approximately 10,000 K.
I don't think gasoline burns that hotly. :-) The Sun's surface
is about 5800 K.
I refuse to drive beneath the sun's surface.
Good for you. :-) You might live longer that way. :-)
(Fun fact: it's impossible to get anything hotter than the
Sun's surface by using lenses and mirrors. Of course, the
Take a small black hole, with mirrors in orbit around it at
..nC
Reflect sunlight from these mirrors onto the object being heated.
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| User: "Uncle Al" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 04:11:36 PM |
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Laurent wrote:
Can't you guys read or what? The additional power comes from an
additional generator coupled to an intake turbine. The engine
wouldn't be powering the extra generator, atmospheric pressure
would. Read again.
Yer stooopid. Atmospheric pressure is at both ends of the engine.
What powers the air sucker? The engine. Oh no! The air is scooped
in as the engine roars forward. Now what powers the air sucker? The
engine. Oh no! The air sucker is powered by a battery! Now what
powers the air sucker? The engine. On no! The air sucker has a
separate engine! Now what powers the air sucker? The other engine -
with crappy efficiency. Oh no! There is whole stack of engines
alternately powering the air suckers... The engine. Sadie Carnot
wins.
Superchargers (run off the engine) and turbochargers (run off the
exhaust) are old stuff. Why not add a Peltier stack at the rear and
power an Autosuck off the exhaust temperature?
Idiot.
You could have a nice fuel cell and electric motor. Pour in ethanol
from agriculture (losing 2/3 of total energy input already), reform it
to hydrogen and carbon monoxide (losing about 20% of the energy in the
ethanol alone), separate out the CO with a Pd/Ag membrane (lose
another 5% vs. ethanol; CO poisons fuel cells). Now put the hydrogen
through the fuel cell and get 85% efficiency vs. hydrogen.
Idiot.
Whatcha gonna do with the CO, burn it to CO2 as an open flame? HA HA
HA.
--
Uncle Al
http://www.mazepath.com/uncleal/qz.pdf
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)
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| User: "EjP" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 12:18:30 PM |
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Opus Penguin wrote:
Ian Stirling wrote:
In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
The requestor should be interned in guantanamo bay.
You can't get 97% from an internal combustion engine on earth
for basic thermodynamic reasons.
Heat loss is the biggest issue, no? Could they line the cylinder walls,
piston top, and valves with some sort of bakelite to keep the heat in the
chamber? That would help, wouldn't it? Also, don't they lose energy in
unspent gasses? Can't they put in 3 or 4 spark plugs per cylinder to make
sure they burn every last drop of fuel mixture?
I think he was referring to the maximum efficiency out of any engine,
which is (Thot-Tcold)/Thot. If you take the cold bath to be the
typical environment - about 300K - then you would need an operating
temperature of at least 10,000K to get 97% efficiency, even if you
could somehow get a perfect Carnot cycle. I think the typical
combustion energy of gasoline is around 2000K, so this sounds like
a stretch.
-E
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| User: "tadchem" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 01:55:33 PM |
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"EjP" <nospam@hackers.are.bad> wrote in message
news:c2ag5t$r0v$1@info4.fnal.gov...
<snip>
I think he was referring to the maximum efficiency out of any engine,
which is (Thot-Tcold)/Thot. If you take the cold bath to be the
typical environment - about 300K - then you would need an operating
temperature of at least 10,000K to get 97% efficiency, even if you
could somehow get a perfect Carnot cycle. I think the typical
combustion energy of gasoline is around 2000K, so this sounds like
a stretch.
Correct.
To this I would like to add that Edison, in his search for filaments for his
incandescent lamp, needed to find a material that could maintain structural
integrity (i.e. it would not melt) at the highest temperature possible -
because emissivity (brightness) increases rapidly with temperature (to the
fourth power as I recall) and spectral characteristics of light are ideal
for humans at 6000K.
The best he could do was with tungsten, which melts at about 3683K.
This would limit the efficiency of a real-world internal combustion engine
to a little over 92%.
Each percentage point gain in efficiency costs more than the previous one.
Tom Davidson
Richmond, VA
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| User: "Ian Stirling" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 02:34:09 PM |
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In sci.physics tadchem <tadchemNOSPAM@comcast.net> wrote:
"EjP" <nospam@hackers.are.bad> wrote in message
news:c2ag5t$r0v$1@info4.fnal.gov...
<snip>
I think he was referring to the maximum efficiency out of any engine,
which is (Thot-Tcold)/Thot. If you take the cold bath to be the
typical environment - about 300K - then you would need an operating
temperature of at least 10,000K to get 97% efficiency, even if you
could somehow get a perfect Carnot cycle. I think the typical
combustion energy of gasoline is around 2000K, so this sounds like
a stretch.
Correct.
To this I would like to add that Edison, in his search for filaments for his
incandescent lamp, needed to find a material that could maintain structural
integrity (i.e. it would not melt) at the highest temperature possible -
because emissivity (brightness) increases rapidly with temperature (to the
fourth power as I recall) and spectral characteristics of light are ideal
for humans at 6000K.
The best he could do was with tungsten, which melts at about 3683K.
This would limit the efficiency of a real-world internal combustion engine
to a little over 92%.
It's not completely inconcievable to imagine am engine using liquid
cylinder liners and pistons.
Osmium boils at some 6000K.
There are some minor engineering details to be solved.
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| User: "tadchem" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
06 Mar 2004 10:18:56 AM |
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"Ian Stirling" <root@mauve.demon.co.uk> wrote in message
news:5v52c.17933$Y%6.1648382@wards.force9.net...
<snip>
It's not completely inconcievable to imagine am engine using liquid
cylinder liners and pistons.
Osmium boils at some 6000K.
There are some minor engineering details to be solved.
Such as finding a container for a 6000K liquid that will also withstand the
pressures exerted by the working fluid...
How do you *mount* a liquid engine block???
Tom Davidson
Richmond, VA
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| User: "Gregory L. Hansen" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
06 Mar 2004 04:54:00 PM |
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In article <KJadnSoPFuk_ZNTdRVn-hA@comcast.com>,
tadchem <tadchemNOSPAM@comcast.net> wrote:
"Ian Stirling" <root@mauve.demon.co.uk> wrote in message
news:5v52c.17933$Y%6.1648382@wards.force9.net...
<snip>
It's not completely inconcievable to imagine am engine using liquid
cylinder liners and pistons.
Osmium boils at some 6000K.
There are some minor engineering details to be solved.
Such as finding a container for a 6000K liquid that will also withstand the
pressures exerted by the working fluid...
How do you *mount* a liquid engine block???
I'm reminded of some *ahem* speculative designs for fission rockets. The
classic nuclear rocket passes hydrogen through a reactor core to heat it.
But heat must diffuse from the fuel into the gas, so the temperature
can't get as high as that of a typial chemical rocket. The improvement in
specific impulse comes strictly from the molecular weight of the
propellant.
Improving on that design was one that allowed the fuel to actually melt in
a centrifuge, and the propellant would be bubbled up through it. Going a
step further was a design that would allow the fuel to vaporize in a
cyclone chamber which would contain "most" of it.
These sorts of ideas were thrown around back in the days when they could
consider feasible such ideas as nuclear-powered airplanes, rockets
propelled by fission bombs, and x-ray lasers powered by same. Ah, we
sorely miss the Golden Age of nuclear power.
--
"Are those morons getting dumber or just louder?" -- Mayor Quimby
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| User: "Russ Lyttle" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
06 Mar 2004 07:12:45 PM |
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Gregory L. Hansen wrote:
In article <KJadnSoPFuk_ZNTdRVn-hA@comcast.com>,
tadchem <tadchemNOSPAM@comcast.net> wrote:
"Ian Stirling" <root@mauve.demon.co.uk> wrote in message
news:5v52c.17933$Y%6.1648382@wards.force9.net...
<snip>
It's not completely inconcievable to imagine am engine using liquid
cylinder liners and pistons.
Osmium boils at some 6000K.
There are some minor engineering details to be solved.
Such as finding a container for a 6000K liquid that will also withstand
the pressures exerted by the working fluid...
How do you *mount* a liquid engine block???
I'm reminded of some *ahem* speculative designs for fission rockets. The
classic nuclear rocket passes hydrogen through a reactor core to heat it.
But heat must diffuse from the fuel into the gas, so the temperature
can't get as high as that of a typial chemical rocket. The improvement in
specific impulse comes strictly from the molecular weight of the
propellant.
Improving on that design was one that allowed the fuel to actually melt in
a centrifuge, and the propellant would be bubbled up through it. Going a
step further was a design that would allow the fuel to vaporize in a
cyclone chamber which would contain "most" of it.
These sorts of ideas were thrown around back in the days when they could
consider feasible such ideas as nuclear-powered airplanes, rockets
propelled by fission bombs, and x-ray lasers powered by same. Ah, we
sorely miss the Golden Age of nuclear power.
--
"Are those morons getting dumber or just louder?" -- Mayor Quimby
Remember the movie "From the Earth to the Moon"? The rocket was propelled by
pumping water through a reactor turning it to steam. A cool idea, except
when you try to pre-heat the reactor without any water for a moderator.
--
Russ Lyttle
lyttlec(@)earthlink.net
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| User: "Franz Heymann" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 04:07:17 PM |
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"EjP" <nospam@hackers.are.bad> wrote in message
news:c2ag5t$r0v$1@info4.fnal.gov...
Opus Penguin wrote:
Ian Stirling wrote:
In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
The requestor should be interned in guantanamo bay.
You can't get 97% from an internal combustion engine on earth
for basic thermodynamic reasons.
Heat loss is the biggest issue, no? Could they line the cylinder
walls,
piston top, and valves with some sort of bakelite to keep the heat in
the
chamber? That would help, wouldn't it? Also, don't they lose
energy in
unspent gasses? Can't they put in 3 or 4 spark plugs per cylinder to
make
sure they burn every last drop of fuel mixture?
I think he was referring to the maximum efficiency out of any engine,
which is (Thot-Tcold)/Thot.
He did not say so.
If you take the cold bath to be the
typical environment - about 300K - then you would need an operating
temperature of at least 10,000K to get 97% efficiency, even if you
could somehow get a perfect Carnot cycle. I think the typical
combustion energy of gasoline is around 2000K, so this sounds like
a stretch.
You surely did not think that Laurent would bother with such mundane
considerations?
Franz
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| User: "" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
06 Mar 2004 12:02:50 PM |
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In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
It's really very simple and low tech. It is basically an airplane
gasoline motor fitted with a sliding-vane turbine on the intake,
which would take advantage of the air flow created by sea level
atmospheric pressure. Since this would be an airplane engine whose
performance is supposed to peak at high altitudes, or at low
atmospheric pressures (airplane engine manufacturers do this by
simply using a specially grinded camshaft), and since my generator
is supposed to work at sea level, at standard atmospheric pressure,
the air flow restriction caused by the intake turbine would work to
its advantage. The extra power would come from a generator attached
to the intake sliding-vane turbine.
--
Laurent
If DOE is actually concidering this, they need to read a few aircraft
engine manuals to learn the idea is DOA.
Piston aircraft engine performance does NOT peak at high altitude, it
peaks at sea level (or below is you can get there).
Before anyone says blower, all a turbo does is increase the maximum
altitude where the engine continues to develop usefull power.
Piston AIRPLANES are "more efficient" at altitude because the aircraft
drag decreases faster than the engine output.
Let's look at the performance chart for a Cessna 172N for power output
airspeed and fuel flow at 2500 RPM and standard temperature:
air fuel
Alt % BHP speed GPH
2000 75 116 8.4
4000 71 115 8.0
6000 67 115 7.6
8000 64 114 7.2
10000 61 114 6.8
12000 58 113 6.6
Maximum obtainable power at 12000 feet is 64% at 2600 RPM and 7.2 GPH
giving a true airspeed of 118 knots.
Since the intial premise is utter nonsense, there is no need to do an
analysis of the rest of the idea.
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "Russ Lyttle" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
06 Mar 2004 07:07:57 PM |
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wrote:
In sci.physics Laurent <cyberdyno4@starpower.net> wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
It's really very simple and low tech. It is basically an airplane
gasoline motor fitted with a sliding-vane turbine on the intake,
which would take advantage of the air flow created by sea level
atmospheric pressure. Since this would be an airplane engine whose
performance is supposed to peak at high altitudes, or at low
atmospheric pressures (airplane engine manufacturers do this by
simply using a specially grinded camshaft), and since my generator
is supposed to work at sea level, at standard atmospheric pressure,
the air flow restriction caused by the intake turbine would work to
its advantage. The extra power would come from a generator attached
to the intake sliding-vane turbine.
--
Laurent
If DOE is actually concidering this, they need to read a few aircraft
engine manuals to learn the idea is DOA.
Piston aircraft engine performance does NOT peak at high altitude, it
peaks at sea level (or below is you can get there).
Before anyone says blower, all a turbo does is increase the maximum
altitude where the engine continues to develop usefull power.
Piston AIRPLANES are "more efficient" at altitude because the aircraft
drag decreases faster than the engine output.
Let's look at the performance chart for a Cessna 172N for power output
airspeed and fuel flow at 2500 RPM and standard temperature:
air fuel
Alt % BHP speed GPH
2000 75 116 8.4
4000 71 115 8.0
6000 67 115 7.6
8000 64 114 7.2
10000 61 114 6.8
12000 58 113 6.6
Maximum obtainable power at 12000 feet is 64% at 2600 RPM and 7.2 GPH
giving a true airspeed of 118 knots.
Since the intial premise is utter nonsense, there is no need to do an
analysis of the rest of the idea.
--
Jim Pennino
Remove -spam-sux to reply.
An additional point is that you can't get more power by increasing fuel
flow. There isn't enough air to burn extra fuel. Effeciency will decrease
if extra fuel is injected. I mention this because I'm right now fixing an
engine where an idiot thought he could do just that.
The advantage of flying at altitude is you get a fuel savings of 21% at a
cost of 2.6% in air speed. That means either an increase in range or
savings in cost.
--
Russ Lyttle
lyttlec(@)earthlink.net
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| User: "Uncle Al" |
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| Title: Re: A gasoline generator with a 97% efficiency rating. |
05 Mar 2004 01:38:48 PM |
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Laurent wrote:
DOE is considering a grant request for a gasoline generator
prototype which could operate at about 97% efficiency. Currently the
best they can do is about 65%, the rest is lost as heat.
It's really very simple and low tech. It is basically an airplane
gasoline motor fitted with a sliding-vane turbine on the intake,
which would take advantage of the air flow created by sea level
atmospheric pressure. Since this would be an airplane engine whose
performance is supposed to peak at high altitudes, or at low
atmospheric pressures (airplane engine manufacturers do this by
simply using a specially grinded camshaft), and since my generator
is supposed to work at sea level, at standard atmospheric pressure,
the air flow restriction caused by the intake turbine would work to
its advantage. The extra power would come from a generator attached
to the intake sliding-vane turbine.
Hey stooopid - Second Law vs. source and sink temps for a heat
engine. You are a liar, an imbecile, or a crook. Do not think of
each category as being exclusive of the others.
--
Uncle Al
http://www.mazepath.com/uncleal/qz.pdf
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)
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